Upper Body Workout Doesn't Impair 48h Leg-Day Recovery, Lactobacillus for Immunity & Alcohol Impairs Your Gains

PWO alcohol is not for male athletes. But before you rejoice, ladies. The ill health effects of a given amount of alcohol are more severe for the fairer sex.

It's Christmas! And you can almost smell the new year with its smell of alcohol approach... and that's bad news for your gains, as a recent study in the latest issue of the Journal of Strength and Conditioning Research shows. With a study on the possible interference of upper body training on your leg-day recovery (Abaïdia. 2017), and the purported benefits of lactic acid bacteria for athletes' immunity (Michalickova. 2017), Duplanty's study, which shows that alcohol will impair the adaptation to resistance training in previously resistance trained men, but not female trainees w/ RT experience (Duplanty. 2017), constitutes what's probably going to be the last SuppVersity Science Update for 2016.

Read about rather exercise-related studies at the SuppVersity

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• Doing an upper body workout after muscle damaging "leg day" won't impair your recovery, study shows (Abaïdia. 2017) -- The purpose of this study was to investigate the effects of an upper-limb strength training session the day after an exercise inducing muscle damage on recovery of performance.
  
  

  

  Figure 1: Creatine kinase (CK) and muscle force recovery ofter the 48h period w/ and w/out upper body exercise on the day after the leg workout (Abaïdia. 2017).

  In a randomized crossover design, subjects performed the day after the exercise, on 2 separate occasions (passive vs. active recovery conditions) a single-leg exercise (dominant in one condition and nondominant in the other condition) consisting of 5 sets of 15 eccentric contractions of the knee flexors. Active recovery consisted of performing an upper-body strength training session the day after the exercise. Creatine kinase, hamstring strength, and muscle soreness were assessed immediately and 20, 24, and 48 hours after exercise-induced muscle damage.
  
  The upper-body strength session, after muscle-damaging exercise accelerated the recovery of slow concentric force (effect size = 0.65; 90% confidence interval = −0.06 to 1.32), but did not affect the recovery kinetics for the other outcomes. The addition of an upper-body strength training session the day after muscle-damaging activity does not negatively affect the recovery kinetics.
  
  "Upper-body strength training may be programmed the day after a competition," the authors conclude and rightly so, after all their efforts to measure Creatine kinase, hamstring strength, and muscle soreness does indeed provide reliable information about the subjects' recovery.
• Lactobacillus helveticus Lafti L10 as an immune booster for elite athletes (Michalickova. 2017) -- To test the influence of probiotic supplementation on humoral immune response, a double-blind, placebo-controlled trial was conducted. Thirty athletes (24 males and 6 females, females: V_O2max 38.2 ± 4.9 ml·kg−1·min−1, age 23.2 ± 1.4 years; males: V_O2max 57.5 ± 9.2 ml·kg−1·min−1, age 24.0 ± 2.4 years, mean ± SD) were randomized either to the probiotic group (Lactobacillus helveticus Lafti L10, 2 × 1010 colony-forming units) or to the placebo group. Serum and saliva samples were collected at the baseline and after 14 weeks. Total and specific antibacterial antibody levels of IgM, IgG, and IgA classes were determined for different bacteria in the serum, and in saliva, total and specific antibacterial IgA levels were examined.
  
  

  

  Teddy bears are like vitamin C and zinc. They can help you when you are already sick, but what are supplements athletes and gymrats take in advance to survive the flu season without getting sick at all?

  The scientists' analyses showed: Total IgM was elevated in both probiotic (18%, 15–20%; mean, 90% confidence interval; p = 0.02) and placebo group (35%, 22–47%; p = 0.02), without observed differences in changes between the groups. No significant changes in IgM levels specific for tested bacteria were found. Total IgG level was constant in both groups. A significant (16%, −2.8 to 35%, p = 0.04) reduction of anti–Enterococcus faecalis IgG was noted in the placebo group, in comparison with the probiotic group.
  
  There was a substantial decrease in total IgA level in the placebo group, when measured either in serum (15%, 12–18%, p = 0.04) or in saliva (35%, −1.4 to 53%, p = 0.03).
  
  Significantly reduced levels of serum anti–lactic acid bacteria IgA antibodies in the placebo group compared with the probiotic group were detected for Lactobacillus rhamnosus LA68 (24%, 5.8–42%, p = 0.02) and for L. rhamnosus LB64 (15%, 2.7–27%, p = 0.02).
  
  Nice? Well, there's one word in the scientists' conlusion I want you to pay specific attention to the small word "could" in "Probiotic administration could have beneficial effects on systemic humoral and mucosal immune responses" (Michalickova. 2017).
• Alcohol post-workout = impaired gains, at least in men (Duplanty. 2017) -- If this is not surprising to you, you must be unaware of the mixed evidence from previous studies on the impact of alcohol on post-workout protein synthesis.
  
  

  

  Figure 2: Bar graphs represent the quantification of western blot images for proteins (phosphorylated proteins relative to total proteins and normalized to a-tubulin | Duplanty. 2017).

  The purpose of the latest study on this subject was to further elucidate the effects postexercise alcohol ingestion.
  
  In that, the study had many novel aspects including using a resistance exercise (RE) only exercise design and the inclusion of women. Ten resistance-trained males and 9 resistance-trained females completed 2 identical acute heavy RE trials (6 sets of Smith machine squats) followed by ingestion of either alcohol or placebo.
  
  All participants completed both conditions. Before exercise (PRE) and 3 (+3 hours) and 5 (+5 hours) hours postexercise, muscle tissue samples were obtained from the vastus lateralis by biopsies. Muscle samples were analyzed for phosphorylated mTOR, S6K1, and 4E-BP1.
  
  For men, there was a significant interaction effect for mTOR and S6K1 phosphorylation. At +3 hours, mTOR and S6K1 phosphorylation (unlike mTOR S6K1 is usually a reliable marker of protein synthesis) was higher for placebo than for alcohol.
  
  For women, there was a significant main effect for time. mTOR phosphorylation was higher at +3 hours than at PRE and at +5 hours.  There were no significant effects found for 4E-BP1 phosphorylation in men or women.

  "The major findings of this study was that although RE elicited similar mTORC1 signaling both in men and in women, alcohol ingestion seemed to only attenuate RE-induced phosphorylation of the mTORC1 signaling pathway in men" (Duplanty. 2017)

  Yes, guys, that's right: alcohol should not be ingested after RE as this ingestion could potentially hamper the desired muscular adaptations to RE by reducing anabolic signaling. The one thing that's still necessary, now, is a study investigating the dose-response effect and whether it takes vodka (40% vol/vol alcohol; Smirnoff Co., Norwalk, CT, USA) diluted in water at a concentration of 15% vol/vol absolute alcohol and thus a dose of 1.09 g of alcohol per kg of fat-free body mass to do the ergolytic trick.

Health food for sick people - Much better than cholesterol supplements ;-) -- Cholesterol Boosts Your Immune Defenses: Infections Can Lower Cholesterol, Extra-Chol. Will Help You Battle Them | Learn more

So, here's what you should remember: (1) You can do upper body workouts the day after hitting your legs without compromising your muscular recovery, but you must not forget that your central nervous system needs time to recover, too. Accordingly, the long-term performance effects of doing this regularly may differ significantly with the CNS beating taking it's toll after a certain number of back to back workouts. (2) Your immunity could benefit from lactobacillus supplements, but don't dare paying for these supps before you don't get at least enough cholesterol to fuel your immune function. (3) As a man, you want to pay particular attention not to go overboard on alcohol, as it appears to have sign. more pronounced effects on you compared to your significant other | Comment! 

References:

• Abaïdia, A-E, Delecroix, B, Leduc, C, Lamblin, J, McCall, A, Baquet, G, and Dupont, G. Effects of a strength training session after an exercise inducing muscle damage on recovery kinetics. J Strength Cond Res 31(1): 115–125, 2017.
• Duplanty, AA, Budnar, RG, Luk, HY, Levitt, DE, Hill, DW, McFarlin, BK, Huggett, DB, and Vingren, JL. Effect of acute alcohol ingestion on resistance exercise–induced mTORC1 signaling in human muscle. J Strength Cond Res 31(1): 54–61, 2017
• Michalickova, DM, Kostic-Vucicevic, MM, Vukasinovic-Vesic, MD, Stojmenovic, TB, Dikic, NV, Andjelkovic, MS, Djordjevic, BI, Tanaskovic, BP, and Minic, RD. Lactobacillus helveticus Lafti L10 supplementation modulates mucosal and humoral immunity in elite athletes: a randomized, double-blind, placebo-controlled trial. J Strength Cond Res 31(1): 62–70, 2017.

Spore-Forming Probiotics - The Better Probiotics? Review

Sauerkraut is one of the best known probiotic foods, but there's more: Kefir & yogurt, kimchi, kombucha, miso, pickles, apple cidar vinegar, and - as discussed recently - raw cheese.

I found out rather accidentally that there is a potentially relevant difference between "probiotics" and "spore-forming probiotics". Relevant enough for me to believe that you should learn about this difference, as well. After all, it seems as if the spores, you will probably only know from anthrax, provide a solution to the #1 major obstacle of efficient probiotic therapies: the destruction and digestion of the life bacteria before they even reach their destination in the colon.

If we go by the WHO definition probiotics are "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host" (FAO/WHO. 2002) - spore-forming or not, stable or unstable freeze dried or encapsulated.

You can learn more about the gut & your health at the SuppVersity

Bugs Dictate What You Crave

Sweeteners & Your Gut

Foods, Not Ma- cros for the Gut

Lactulose For Gut & Health

Probiotics Don't Cut Body Fat

The Macrobiotic MaPi2.0 Diet

Not all of them, however, share the often mourned lack of shelf-life and susceptibility to breakdown in the acidic milieu of the upper gastroinstestinal tract. This is why chances are that only a very small percentage of your probiotic supplement is (a) viable at the end of its shelf-life and (b) able to transit the ph-barrier of your upper gastrointestinal tract.

Figure 1: Illustration of the process of spore-formation from a presentation by Marthese Azzopardi.

The most commonly available alternative that will guarantee both, i.e. a long shelf-life and successful transit of the intestinal pH barrier is "Bacillus coagulans", a gram-positive, spore-forming, microaerophilic, lactic-acid producing bacillus that is not - by definition - part of the Lactobacillus genus; and that despite the fact that it is still often falsely referred to and even labelled as "Lactibacillus sporogenes"... needless to say: you also have to distinguish coagulans from unfortunately better-known spores such as ahtrax, the 1,300 year old lethal weapon of terror.

What's special about spore-forming probiotics?

B. coagulans and other spore-forming probiotics protect themselves with a unique spore-like protein coating, "which allows it to survive stomach acid, reach the small intestine, germinate, and multiply" (Jurenka. 2012). As Jurenka et al. point out in their 2012 review of the literature ...

"[...] B. coagulans arrives in the stomach in its spore form, where it is exposed to the stomach's churning action and acidic pH that causes the spore coating to absorb water, swell, and begin the germination process. Upon arrival in the duodenum, the spores germinate and multiply rapidly" (Jurenka. 2012). 

Ghandi et al. have estimate the average duration of time between oral consumption and germination to be roughly 4-6 hours (Gandhi. 1988). This, alone, obviously isn't a major advantage. Rather than the time to germination, it is their ability to germinate in the intestinal tract, at all, that makes them stand out of the probiotic crowd. With a 85% survival rate (meaning 85% of the starting material reaching the intestinal tract intact), B coagulans is the #1 among easily obtainable probiotics when it comes to becoming metabolically active in the intestines (other species such as lactobacilli require special treatment like micro-encapsulation to achieve similar absorption rates | Kailasapathy. 2000).

Figure 2: Many scientists believe that our battle against commensurable bacteria is the reason for many modern diseases (auto-)immune diseases.

Once they are there, B. cuagulans does practically the same as the often hailed lactobacillii strains: it produces levorotatory L(+)lactic acid (Ong. 2016), the form most readily metabolized in glycogen synthesis by the body (i.e., the isomeric form that would not be expected to contribute to metabolic acidosis).

What is particularly intriguing, though, is that they do so without superseeding their 'regular' cousins, because the colonization is transient and the spores of B. coagulans are excreted slowly via the feces for approximately seven days after discontinuation of administration (Majeed. 1998).

Wait - If it doesn't stay, how does it work?

As Jurenka et al. highlight in their previously referenced review, B. cuagulans will, despite the transient of this organism in the digestive tract, "produce a shift in the intestinal environment in support of a complex gastrointestinal flora" (Jurenka. 2012). In pigs which constitute the best animal model for the human digestive tract, for example, they have been shown to reduce 'bad' bacteria as effectively as antibiotics (Adami. 1999) - and they do that without negative impact on any of the 'good' bacteria which makes them the ideal , and meanwhile scientifically proven - alternative for the chronic administration of antibiotics in livestock breeding (Zhenya. 2015).

Can't these bacilli harm you? Toxicological safety assessments for B. coagulans indicate no mutagenic, clastogenic, or genotoxic effects. Results of an acute and 90-day subchronic oral toxicity study in rats yielded a No Adverse Effects Level (NOEL) greater than 1,000 mg/kg per day (Endres. 2009). As Jurenka et al. point out in their review, Endres et al. used B. coagulans at a concentration equal to 95.2 x 10^11, i.e. almost 100 billion CFU for a 70-kg human - that's 30x more than the typical upper limit you will find in supplements which are usually dosed between 100 million an 3 billion CFUs daily. Furthermore, "in humans, adverse reactions following supplementation have not been reported in the peer-reviewed literature" - and this includes even minor side effects such as bloating. More recently human safety data for another strain has been published (Majeed. 2016c).

This effect is presumably mediated by improvements of the gastrointestinal ecology, replenishing the quantity of desirable obligate microorganisms and antagonizing pathogenic microbes (Jurenka. 2012), which, in turn, is a result of the increased production of bacteriocins, bacteriocin-like substances, which are both germ-specific natural antibiotics, as well as short-chain fatty acids that nourish the colonic mucosa (Mandel. 2010). This and direct influence on local and systemic inflammation that have been observed in vitro and - as in the case of the arthritic subjects in Mandel's 2010 study - in vivo, explains the repeatedly observed effects of B. coagulans on both, gastrointestinal disorders (local inflammation) and metabolic disease & inflammatory diseases such as arthritis.

Proven health benefits of B. coagulans, the most widely available form of spore-forming probiotics (there are different strains available and there's insufficient evidence to compare their efficacy, though) that have been documented in animal and human studies and summarized in reviews are similar to what you already have seen with classic probiotics:

• improved digestion, esp. of lactose, because B. coagulans shows [beta]-galactosidase (lactase) activity in vitro and may also have lactic acid dehydrogenase activity, thereby enhancing the digestibility of lactose in those who are lactose intolerant (Jurenka. 2012) 
• improved cholesterol levels, because B. coagulans assimilates and incorporates cholesterol into its cellular structure, binds cholesterol in the gut, and may inhibit the cholesterol-producing enzyme HMG-CoA reductase | Mohan. 1990)
  

  

  Figure 3: As early as in 1990, Mohan et al. observed that the provision of "only" 360 million CFU of B. coagulans can significantly improve the cholesterol profile of  17 patients with type II hyperlipidemia (Mohan. 1990).

• promotion of a healthy, balanced microbiome (+ all downstream health benefits), especially after antibiotic treatments and in the aging population in whom the prevalence of 'good' bacteria declines (Nyangale. 2015), because of B. cuagulans ability to prevent and counter dysbiosis, i.e. the over-growth of pathogenic microorganisms, battle irritable bowel syndeome (IBS), prevent antibiotic-associated or regular diarrhea (duration of diarrhea in kids is reduced by 12% | Dutta. 2011) and + flatulence (Kalman. 2009) and help the body cope with viral attacks (e.g. influenca; see Baron. 2009)
  

  

  Figure 4: Compared to regular probiotics B. coagulans is surprisingly effective at low doses of 5 million CFU when it comes to managing diarrhea in IBS patients (Majeed. 2016a).

• athletic performance can be enhanced by B coagulans' ability to reduces indices of muscle damage, increases recovery and may maintain athletic performance after muscle damaging exercise (Jäger. 2015) - at least according to a recent study in which 30 healthy recreationally-trained males (mean+/-SD; age: 21.5 ± 2.8 years; height: 177.4 ± 8.0 cm; weight: 89.7 ± 28.2 kg) were randomly assigned to consume either 20 g of casein (Control = CON) or 20 g of casein plus probiotic (500M CFU | BC30) twice daily in a crossover, diet-controlled design for a two-week time period.
  

  

  Figure 5: In recreationally trained subjects, supplementing with B. coagulans prevents muscle damage and enhances subjective and objective measures of recovery from hitting the weights (Jäger. 2015).

  Subjects performed a damaging exercise bout consisting of 10 sets × 10 repetitions unilateral leg press at 70% 1 RM with 1 minute rest, one legged - leg extension (5 sets × 12 reps), and rear foot elevated split squat 5 sets × 12 reps with one minute rest at baseline and after two weeks of supplementation. Athletic performance consisting of peak power (Wingate 10 sec Peak Power Assessment at 7.5% BW at 175RPM threshold loaded drop), vertical jump power (Tendo unit, single-leg jump), and 1-RM single-leg press; and muscle damage was analyzed by muscle swelling (ultrasonography) and blood draws (creatine kinase (CK), blood urea nitrogen (BUN)) were taken at baseline (pre-supplementation) and 48 hours after damaging exercise bout. Perceptual measures (perceived recovery, soreness) were taken before, 24, 48 and 72 hours after exercise.
  
  The results are quite convincing: (1) the supplement significantly increased recovery at 24 and 72 hours, and decreased soreness at 72 hours post exercise in comparison to CON; and that's based on perceptual measures and (2) reduced increase in CK (CON: +266.8%, p = 0.0002; BC30: +137.7%, p = 0.01), as well as (3) preserved athletic performance in in BC30 (+10.1 watts, +1.7%) vs. CON (Wingate Peak Power; CON: (-39.8 watts, - 5.3%, p = 0.03).
• women's health, when administered locally, B. coagulans have also been shown to be an anti-biotic alternative for women suffering from non-specific vaginitis (Shirodkar. 1980) - simply eating them will yet obviously not necessarily have that effect, ladies

Now all these are nice to have, but what my be of even greater importance is the fact that their resiliance makes B. coagulans the ideal addon to commercially available foods (even in liquids the bacteria will survive 6-24 months (!) | Majeed. 2016b), where their downstream effects on your metabolism (think of the microbiome <> diabesity connection) may help us control the obesity and diabetes epidemic... what? Oh, yes! There's an emphasis on "may", whether this is actually going to be the case will have to be confirmed in future studies, obviously ;-)

Yes, diet may affect your microbiome. Whether the changes are (a) relevant or (b) irrelevant is yet as questionable as whether the changes the scientists observed will (i) have a negative (ii) a positive or (iii) no effect | learn more.

So, you better take spore-forming vs. 'normal' probiotics? Well, I guess it would be too early to say that, but the fact that Russian scientists report that B. coagulans treatment in conjunction with traditional probiotics results in 20- to 30-percent higher treatment efficacy in humans with bacterial dysbiosis than traditional probiotics such as Lactobacillus acidophilus or Bifidobacteria alone (Voĭchishina. 1991). Since neither I nor one of the reviews I have read had access to an English version of Voĭchishina's paper, I cannot tell you whether the design allows any conclusions as to whether it is the combination of both or simple the addition of B. cougulans that is responsible for the 20-30% increase in efficacy.

In view of the fact that respective supplements are - in contrast to what you may think now - not extremely expensive and considering the fact that dosages as low as 100 million CFU have been shown to have significant health effects, it may not hurt to give B. cuagulans, which is currently the only easily obtainable sporeforming probiotic a try (don't ask me about the exact strain, though, there is insufficient evidence to say which one is best and if they even have sign. different health effects) - especially if you're having issues with your digestive tract: 30 days and if it doesn't work, you can still drop it | Comment on Facebook!

References:

• Adami, Annunciata, and Valeria Cavazzoni. "Occurrence of selected bacterial groups in the faeces of piglets fed with Bacillus coagulans as probiotic." Journal of basic microbiology 39.1 (1999): 3-10.
• Baron, Mira. "Original research: A patented strain of bacillus coagulans increased immune response to viral challenge." Postgraduate medicine 121.2 (2009): 114-118.
• Dutta, Phalguni, et al. "Randomised controlled clinical trial of Lactobacillus sporogenes (Bacillus coagulans), used as probiotic in clinical practice, on acute watery diarrhoea in children." Tropical Medicine & International Health 16.5 (2011): 555-561.
• FAO/WHO Joint Working Group Report on Drafting Guidelines for the Evaluation of Probiotics in Food. London, Ontario, Canada; April 30 and May 1, 2002.
• Gandhi, A. B. "Lactobacillus sporogenes, an advancement in Lactobacillus therapy." The Eastern Pharmacist (1988): 41-43.
• Jäger, Ralf, et al. "Effects of probiotic supplementation on markers of skeletal muscle damage, perceived recovery and athletic performance after an intense single leg training bout." Journal of the International Society of Sports Nutrition 12.Suppl 1 (2015): P36.
• Jurenka, Julie S. "Bacillus coagulans." Altern. Med. Rev 17 (2012): 76-81.
• Kailasapathy, Kaila, and James Chin. "Survival and therapeutic potential of probiotic organisms with reference to Lactobacillus acidophilus and Bifidobacterium spp." Immunology and Cell Biology 78.1 (2000): 80-88.
• Kalman, Douglas S., et al. "A prospective, randomized, double-blind, placebo-controlled parallel-group dual site trial to evaluate the effects of a Bacillus coagulans-based product on functional intestinal gas symptoms." BMC gastroenterology 9.1 (2009): 1.
• Majeed, Muhammed, et al. "Bacillus coagulans MTCC 5856 supplementation in the management of diarrhea predominant Irritable Bowel Syndrome: a double blind randomized placebo controlled pilot clinical study." Nutrition journal 15.1 (2016a): 1.
• Majeed, Muhammed, et al. "Evaluation of the stability of Bacillus coagulans MTCC 5856 during processing and storage of functional foods." International Journal of Food Science & Technology (2016b).
• Majeed, Muhammed, et al. "A Double-Blind, Placebo-Controlled, Parallel Study Evaluating the Safety of Bacillus coagulans MTCC 5856 in Healthy Individuals." Journal of Clinical Toxicology 2016 (2016c).
• Mandel, David R., Katy Eichas, and Judith Holmes. "Bacillus coagulans: a viable adjunct therapy for relieving symptoms of rheumatoid arthritis according to a randomized, controlled trial." BMC complementary and alternative medicine 10.1 (2010): 1.
• Mohan, J. C., R. Arora, and M. Khalilullah. "Preliminary observations on effect of Lactobacillus sporogenes on serum lipid levels in hypercholesterolemic patients." The Indian journal of medical research 92 (1990): 431-432.
• Nyangale, Edna P., et al. "Bacillus coagulans GBI-30, 6086 modulates Faecalibacterium prausnitzii in older men and women." The Journal of nutrition 145.7 (2015): 1446-1452.
• Ong, Shufen Angeline, Zhi Jian Ng, and Jin Chuan Wu. "Production of high concentration of l-lactic acid from cellobiose by thermophilic Bacillus coagulans WCP10-4." Applied microbiology and biotechnology (2016): 1-8.
• Shirodkar, N. V., et al. "Multi-Centre Clinical Assessment Myconip Vaginal Tablets-in Non-Specific Vaginitis." The Indian Practitioner 33.4 (1980): 207-210.
• Zhenya, Zhai, et al. "Effect of dietary supplementation with dimethyl potassium and Bacillus coagulans instead of antibiotics on growth performance and immune parameters in weaned piglets [J]." Feed Industry 12 (2015): 002.

Anti-Microbial Effects of Artificial Sweeteners in Humans - 2/3rds of a Can of Diet Coke May Have a Sign. Effect on the Gut Microbiome, but the Relevance is Questionable

2/3 of this can may suffice to make a difference. Whether this difference is (a) relevant or (b) irrelevant is yet as questionable as whether the changes the scientists observed will (i) have a negative (ii) a positive or (iii) no effect.

As a SuppVersity user you know that the whole craze about aspartam and sucralose is overblown. You will also know that any potential "pro-insulinogenic" effects occurred only in less than a handful of human studies. If they did, though, they occurred in response to the ingestion of artificial sweeteners and glucose or other insulinogenic carbohydrate sources (learn more). Against that background it's also not surprising that in clinical trials vs. observational bogus, artificial sweeteners have been shown to help people with weight problems lose body fat (learn more).

The one thing about the myth of the bad sweetener that has yet not been completely debunked, though, revolves around their negative effects on the human gut microbiome.

You can learn more about the gut & your health at the SuppVersity

Bugs Dictate What You Crave

Sweeteners & Your Gut

Foods, Not Ma- cros for the Gut

Lactulose For Gut & Health

Probiotics Don't Cut Body Fat

The Macrobiotic MaPi2.0 Diet

You will remember from my previous post on this topic that - as (unfortunately) usual - all empirically valid data we have is based on rodent trials. In our mammalian cousins, the consumption of artificially sweetened products on top of an obesogenic diet has in fact been shown to have an additional effect on the modulation of the gut bacteria that appears to make turn an already "bad" diet into a nightmare (learn more). It is yet still very questionable, which part of the research can be translated to humans and to which subgroup of the population this would apply. Even if we assume a 1:1 translation from rodent to human, we would after all have to exclude most of you, because none of you will be consuming a hypercaloric, hyper-processed high fat + high carbohydrate diet (at least that's what I'd hope).

If we trust the results of a soon-to-be-published observational study from the George Mason University, though, our gut microbiomes could be in danger - although no one knows for sure.

Sweeteners, pre- and probiotics are not the only foods / supplements that can have a major impact on the bacterial ecosystem in your gut. Only recently scientists have found that the ergogenic effects of glutamine may also be mediated by the gut | more

Why do you have to care about the microbes in your gut? The good guys produce vitamins like vitamin K for you, they digest resistant starches and produce short-chain fatty acids which in are have beneficial effects on your intestine, your satiety and directly or indirectly even on your glucose control. There is unfortunately no way to really tell the good from the bad guys. At the moment, it would seem as if the lactobacilli and bifidobacteria would be the ones you want to have most. On the other hand, the number of bacteria cells in our gut surpasses the number of cells in our body and form a very complex and vurnerable ecosystem, where too much of one and too little of another species may be more of a problem than "having the wrong bacteria". For now, however, supplements containing various strains of the two aforementioned types of bacteria does in fact seem to be the most promising, but certainly not fully proven strategy to improve ones gastro-intestinal health.

Even if the good guys are unconditionally good, the ambiguous results of pertinent research clearly indicates that this doesn't imply that all of use will benefit from exogenous provisions of bacteria. There are for example both positive and negative associations for certain strains of bifidobacterium or lactobacillus species (Million. 2011), so that supplementation is mostly based on guessing which are good based on individual studies. This is also why I personally believe that tweaking the environment and thus steering the gut microbiome into the right direction with prebiotics, is a more viable and promising strategy than the ingestion of bazillions of preformed bacteria aka probiotics.

In their thorough, but small scale (N=31) analysis, Cara L. Frankenfeld and her colleagues analysed the fecal sample of their subjects using Multitag Pyrosequencing. This allowed them to compare the bacterial abundance and bacterial diversity across consumers and non-consumers of aspartame and acesulfame-K using non-parametric statistics and UniFrac analysis, respectively.

To predict some of the consequences of possible difference in the bacterial make-up Frankenfeld et al. applied a phylogenetic investigation of the communities by reconstruction of unobserved states (PICRUSt) in order to predict mean relative abundance of gene function.

Table 1: There were no sign. differences in BMI, energy intake, total carbohydrate and added sugar intake or the "quality" of the diet (as assessed on the Healthy Eating Index) between AS consumers and non-consumers (Frankenfeld. 2015)

Thus, the results of the gene function analysis must be met with a healthy degree of skepticism, because unlike the bacterial counts and diversity, which was also just estimated based on what "left" the subjects in form of feces, the gene assay is a model-based result... think of it like the weather forecast, one of which studies say it's relatively reliable (Langille. 2013).

Don't be a fool, stevia will mess with your microbiome just like if not even more than "unnatural" sweeteners.

Sweeteners could be a bad, but also a good thing. In pigs, SUCRAM® (a mixture of saccharin and neohesperidin dihydrochalcone) will significantly increase the abundance of the allegedly good Lactobacilli by more than 100% (Daly. 2014). In other studies, like the previously discussed study in rodents, saccharin has a negative effect. Whether a 100% increase in Lactobacilli as in Daly et al. (2014) or decreases in other bacteria as they have been observed in several rodent studies is something we'd want or not, is yet totally unknown. It's simply too early to predict the effect. For many of you that may be enough to avoid sweeteners, and I fully understand that.

I just want you to know that stevia is not the "healthy alternative", just because it's "natural". In fact, for stevia we even know that it will kill lactobacilli, i.e. those bacteria of which we think that they are the good guys (learn more about how stevia messes with the gut micriobome).

Among the seven aspartame consumers and seven acesulfame-K consumers (some consumed both), the researchers did indeed find some significant differences in the bacterial make-up compared to those subjects who had abstained from consuming sweeteners in the four days before the fecal samples were collected. I quote from the FT (Frankenfeld. 2015):

• Bacteriodetes and Firmicutes had the highest median abundances and together accounted for the majority of the bacterial class representation in all individuals. 
• The median Bacteriodetes:Firmcutes ratio did not significantly differ across aspartame non-consumers (0.96, range: 0.15-2.97) and consumers (1.08, range: 0.69-1.87), (median test p-value=0.60). 
• There was no overall visual clustering of individuals by acesulfame-K consumption . 
• Overall bacterial diversity evaluated with UniFrac analysis was different across consumers and non-consumers, but there were no significant differences in relative abundance of gene function across consumers and non-consumers (Figure 3).
• There were no observable difference in the three individuals who consumed both aspartame and acesulfame-K (Supplemental Figure 1). 

So, let's briefly sum this up. In line with the overall hysteria about sweeteners, the changes were more significant in the aspartame group (p<0.01) than they were in the acesulfame-K group (p=0.03), but this could be explained by the simple fact that the subjects consumed significantly more aspartame (one can of diet coke contains 150mg, by the way) than acesulfam-K (5.3 mg/day to 112 mg/day vs. 1.7 mg/day to 33.2 mg/day).

Figure 1: Yes, there were differences in the bacterial make-up of the gut microbiome of the four groups, but no one can tell you what these or the vast individual differences in the groups mean for your health (Frankenfeld. 2015) !

Against that background, the "aspartame is the worst" hypothesis could neither be refuted nor supported based on the study at hand, even if the results would signify overall ill-health effects. With all three potentially important markers remaining unchanged, though, this is not the case:

• the ratio of mostly "bad" gram-negative bacteriodetes and "good" gram positive bacteria remained the same - it's thus hard to argue that the subjects who consumed artificial sweeteners had an unhealthier gut microbiome
• there was no general reduction in gut bacteria, which would indicate a general anti-microbial effect of artificial sweeteners as it occurs with antibiotics - it's thus hard to argue that the anti-microbial effects (which don't exist) of artificial sweeteners would leave you similarly defenseless and open to colonization with "bad" bacteria as antibiotics.
• the gene essays say that despite the differences in the numbers of certain bacteria, the gene expression is the same - it's thus hard to argue that there was an epigenetic effect of artificial sweeteners that precipitates us to obesity or even makes us sick / diabetic / whatever

Against that background, there may be an urgent need for future research and technological development that would allow us to go beyond observing changes in the number and ratio of largely unknown gut bacteria that are (as of now) completely meaningless for us. 

Probiotics Inhibit Ill-Health Effects of 7-Day Overfeeding in Man - Does This Make Yakult(R) the Perfect Tool in Your Bulking Toolbox or is it Just Another Marketing Gag? Learn more!

Don't be fooled! Scientists may understand the format of the graph in Figure 1 better, but if they were honest, they would have to admit that they have absolutely no clue what the changes they observed mean. Yes, they can use mathematics to tell you they are statistically significant, but they can't even tell you whether they're rather good or bad for you.

Eventually, the data in Figure 1 shows us only one thing: The gut microbiome is like a finger-print. It's different for all of us and despite changes due to artificial sweetener consumption, there's no clear pattern in any of the artificial sweetener groups that would allow us to predict negative or positive effects based on what we know now.

Against that background I would try not to freak out about the fact that aspartame and acesulfam-k can affect your gut microbiome. There is no, and I repeat, no convincing experimental evidence in humans that would remotely confirm that any potential changes of the gut microbiome that occur in response to the consumption of artificial sweeteners would entail ill health effects. The only thing we have,are observational and epidemiological studies that correlate obesity with artificial sweetener use and are abused by people who don't know or simply ignore the difference between associations and causation as "proof" that artificial sweeteners are (usually together with fructose) at the heart of the obesity epidemic. And even in the study at hand, the dietary control was not rigorous enough to exclude that the observed association was actually due to aspartame and acesulfam-K and not due to other agents in the artificially sweetened drinks or totally different foods, the subjects consumed during the four day lead-in, during the last months, or even chronically for years or decades | Comment on Facebook!

References:

• Daly, Kristian, et al. "Dietary supplementation with lactose or artificial sweetener enhances swine gut Lactobacillus population abundance." British Journal of Nutrition 111.S1 (2014): S30-S35.
• Frankenfeld, Cara L., et al. "High-intensity sweetener consumption and gut microbiome content and predicted gene function in a cross-sectional study of adults in the United States." Annals of Epidemiology (2015).
• Langille, Morgan GI, et al. "Predictive functional profiling of microbial communities using 16S rRNA marker gene sequences." Nature biotechnology 31.9 (2013): 814-821.
• Million, M., et al. "Obesity-associated gut microbiota is enriched in Lactobacillus reuteri and depleted in Bifidobacterium animalis and Methanobrevibacter smithii." International journal of obesity 36.6 (2012): 817-825.

Stevia Kills Good Gut Bacteria - One Study Enough to Stop Using the Natural Sweetener? Probably Not in View of its Anti-Diabetes, Anti-LDL, Anti-Viral & Anti-Cancer Effects

Study indicates stevia kills healthy gut bacteria. So, how bad is it? Are the effects significant, will they have an impact on your overall health and does this mean you must not use stevia any longer?

A recent study from the Institute of Microbiology and Biotechnology at the University of Latvia in Riga shows the impossible: Stevia, the "natural" sweetener that's everybody's darling, could mess up your gut microbiome by killing large numbers of the beneficial Lactobacillus Reuteri bacteria in your tummy - exactly those bacteria of which several studies have shown that supplementing will help cure acute diarrhea in young children (Shornikova. 1997), is capable of reducing frequency and intensity of antibiotic-associated side-effects during eradication therapy for H. pylori. (Lionetti. 2006), confers broad-spectrum protection against disease in humans and animals (Casas. 2000), has cholesterol lowering effects (Jones. 2012) and much much more.

You can learn more about the gut & your health at the SuppVersity

Bugs Dictate What You Crave

Sweeteners & Your Gut

Foods, Not Ma- cros for the Gut

Lactulose For Gut & Health

Probiotics Don't Cut Body Fat

The Macrobiotic MaPi2.0 Diet

In view of the fact that it would appear as id Lactobacillus reuteri was clearly one of the "good guys" it seems that the results I. Denin a, P. Semjonovs, A. Fomina, R. Treimane and R. Linde report on their latest study in Letters in Applied Microbiology (Denin. 2014) were really bad news:

Figure 1: Influence of stevioside (a) and rebaudioside A (b) on biomass formation in Lactobacillus reuteri strains (24 h | Denin. 2014).

"In samples supplemented with stevia glycosides, the growth of all Lact. reuteri strains was slightly inhibited – however, a statistically significant concentration-dependent inhibitory effect was not observed for all strains (Fig. 1).

Comparing both the glycosides, the inhibitory effect of stevioside was more pronounced for strains 44 and 16, while the effect of rebaudioside A was more pronounced for strains 16 and 19. Statistically significant concentration-dependent inhib itory effect was observed for lactic acid and acetic acid synthesis. The decrease in lactic acid and acetic acid production was observed for both stevioside and rebaudioside A. [...] Although the inhibitory effect of stevioside on pH was observed at different stevioside concentrations, the effect was evident for all strains. Rebaudioside A had a more pronounced inhibitory effect on pH values of certain strains including Lact. reuteri 12, 16, 43 and 44" (Denin. 2014 | my emphasis).

The good news, however, is in the details: The inhibitory effect was "slight" (see quotation above) and the design of the study leaves it open, whether similar effects would occur in vivo and thus outside of a glycoside, stevioside and rebaudioside laden Petri dish.

Previous studies seem to refute significant effects of stevia on the human microbiome! In 2003, Gardana et al. found no effect of stevia on the make-up of human fecal cultures when they were incubated with either stevioside or rebaudioside A. Only the fact that bacteroides, i.e. the "enemies" of lactobacilli, were the most efficient in hydrolyzing Stevia sweeteners to steviol would suggest that there may be an overall effect on the human microbiome form stevia (ab-)use.

And while we have little in vivo evidence that stevia is bad for you, a brief review of the contemporary scientific literature on Stevia yields the following "proven" (mostly only in a handful, if not just a single study) benefits:

• Stevia has been implicated in diabetes and hyperlipidemia treatment and its effects on blood glucose levels are not a mere result of the corresponding reduction in sugar intake.

  

  Figure 2: Effects of stevia vs. diabetes drug Glibenclamide on blood glucose and lipid levels in diabetic rodents; data expressed relative to healthy control (Singh. 2014)

  In a recent rodent study that compared the effects of stevia against those of the often-prescribed diabetes-drug Glibenclamide, the natural sweetener outperformed the drug in many in its ability to reduce LDL and blood sugar and was not far off of what the Glibencamide did for the diabetic lab animals in terms of its effects on HDL and VLDL (see Figure 2).
  
  Previous human studies indicate that stevia extracts will also increase the increased 16 healthy human volunteers whose plasma glucose levels during an oral glucose tolerance tests were significantly lower after having consumed 5 grams of aqueous leave extract at regular 6-h intervals for 3 days (Curi. 1985).

  

  Figure 3: Effects of stevia and aspartame replacement of sucrose in test meals that were fed to obese and normal-weight volunteers on postprandial blood glucose levels (Anton. 2010)

  Moreover, in a more recent study by Anton et al. where stevia was compared to aspartame, it had the same beneficial effects on total energy intake and let to statistically significant reductions in postprandial glucose levels of both obese and lean study subjects (see Figure 3) that did not reach significance when the sucrose content of the test meal was replaced by aspartame.
• In-vitro stevia appears to have anti-cancer effects, as well. That's at least what studies by  Jayaraman et al. (2008) observed with stevia extracts. An effect that may be related to both it's anti-microbial, as well as its potent anti-oxidant activity (Tadhani. 2007) of the whole leaves and leave extracts of which Tahani et al. found that they contain significant effects of folic acid (52.18 mg/100 g) and vitamin C, as well as 130.76 μg catechin and 15.64 μg quercetin for leaves and 43.99 μg catechin and 1.57 μg quercetin for cellus at mg of water extracts, respectively.
  
  Furthermore, Tadhani et al.'s results showed that the leaf extracts contained higher amounts of free radicals, hydroxyl radicals and superoxide anion radical scavenging activities than those of the callus extracts or the anti-mutagenic effects Cariño-Cortés et al. report in their 2007 study. Whether anything similar can be observed with the white "stevia" powder that is used by most people to sweeten their foods is yet questionable - it's after all pure steviosid and thus devoid of all of the previously mentioned compounds.

  

  Figure 1: Several natural constituents of the stevia plant, including steviosides, which are the naturally sweet agents in stevia have potent anti-viral activity against Epstein-Barr virus; values in brackets
  represent % of untreated control dish (Konoshima. 2002)

  Another possible anti-cancer mechanism may be related to stevia's ability to kill viruses like the Epstein-Barr virus that has been implicated in the pathogenesis of Burkitt’s lymphoma, Hodgkin’s disease, non-Hodgkin’s lymphoma, nasopharyngeal carcinoma, and lymphomas, as well as leiomyosarcomas arising in immunocompromised individuals.in humans (Thompson. 2014).

Against that background it seems questionable that the new evidence of negative effects on allegedly healthy gut bacteria (just want to remind everyone that we have no clue what the optimal gut microbiome would look like) is significant enough to have us all reconsider our use of tiny amounts of stevia as a sweetener in our foods.

Read more about the effects artificial sweeteners have on the microbiome in a prevoius article | go ahead!

Interim conclusion: While I am not all too scared that stevia will mess with my gut microbiome in a way that makes me sick, fat and what not, I truly believe that the effects of artificial sweeteners on the make-up and density of the human gut microbiome is still massively under-researched - and that in spite of the fact that it could have a significant effect on the health of us all.

As s SuppVersity reader you will also be aware that this is not a stevia-specific effects. Only recently I have written about similar effects for a bunch of artificial sweeteners - an article I can only recommend to anyone who hasn't read it yet | Comment on Facebook.

References:

• Anton, Stephen D., et al. "Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels." Appetite 55.1 (2010): 37-43.
• Casas, Ivan A., and Walter J. Dobrogosz. "Validation of the probiotic concept: Lactobacillus reuteri confers broad-spectrum protection against disease in humans and animals." Microbial ecology in health and disease 12.4 (2000): 247-285. 
• Curi, R., et al. "Effect of Stevia rebaudiana on glucose tolerance in normal adult humans." Brazilian journal of medical and biological research= Revista brasileira de pesquisas médicas e biológicas/Sociedade Brasileira de Biofísica 19.6 (1985): 771-774.
• Deniņa, Ilze, et al. "The influence of stevia glycosides on the growth of Lactobacillus reuteri strains." Letters in applied microbiology 58.3 (2014): 278-284. 
• Gardana, Claudio, et al. "Metabolism of stevioside and rebaudioside A from Stevia rebaudiana extracts by human microflora." Journal of agricultural and food chemistry 51.22 (2003): 6618-6622. 
• Jayaraman, Sathishkumar, Muthu Saravanan Manoharan, and Seethalakshmi Illanchezian. "In-vitro antimicrobial and antitumor activities of Stevia rebaudiana (Asteraceae) leaf extracts." Tropical Journal of Pharmaceutical Research 7.4 (2008): 1143-1149.
• Jones, M. L., C. J. Martoni, and S. Prakash. "Cholesterol lowering and inhibition of sterol absorption by Lactobacillus reuteri NCIMB 30242: a randomized controlled trial." European journal of clinical nutrition 66.11 (2012): 1234-1241.
• Konoshima, Takao, and Midori Takasaki. "Cancer-chemopreventive effects of natural sweeteners and related compounds." Pure and applied chemistry 74.7 (2002): 1309-1316.
• Lionetti, E., et al. "Lactobacillus reuteri therapy to reduce side‐effects during anti‐Helicobacter pylori treatment in children: a randomized placebo controlled trial." Alimentary pharmacology & therapeutics 24.10 (2006): 1461-1468.
• Shornikova, Aino-Vieno, et al. "Lactobacillus reuteri as a therapeutic agent in acute diarrhea in young children." Journal of pediatric gastroenterology and nutrition 24.4 (1997): 399-404.
• Singh, Sunanda. "Antidiabetic, Antidyslipidymic and Antioxidative potential of methanolic root extract of Stevia rebaudiana (Bertoni) on Alloxan induced Diabetic Mice Sunanda Singh and Veena Garg Department of Bioscience and Biotechnology, Banasthali Vidyapeeth, Banasthali, Rajasthan, India." (2014). 
• Tadhani, M. B., V. H. Patel, and Rema Subhash. "In vitro antioxidant activities of Stevia rebaudiana leaves and callus." Journal of Food Composition and Analysis 20.3 (2007): 323-329. 
• Thompson, Matthew P., and Razelle Kurzrock. "Epstein-Barr virus and cancer." Clinical Cancer Research 10.3 (2004): 803-821.

Not All Artificial Sweeteners Are Created Equal: New Studies on Aspartame, Acesulfame-K & Combination of Saccharin + Neohesperidin Dihydrochalcone

It was about time for an artificial sweetener update, wasn't it?

Alright, I have to admit I am not following the artificial sweetener scene closely enough to have heard about SUCRAM, an artificial sweetener that is composed of saccharin (a classic) and neohepseridin dihydrochalcone, the new kid on the blog, which is yet not officially approved by either the FDA or it European equivalent o be used in the processed junk, most people call "food", these days. If we put some faith into the latest study investigating the effects of this agent, which is apparently already heavily used in animal feeds in Europe it does yet "dramatically reduce enteric disease" and "enhance growth performance in early-weaned piglets." (Daly. 2014)

Whether and to which extent these beneficial effects on gut health are mediated by changes in the gut microbiome is yet still uncertain; and since "uncertain" is a word scientists don't like, Kristian Daily and his colleagues from the University of Liverpool conducted a study to find out, whether the non-negligible health benefits would be brought about by AI <> gut interactions.

You can learn more about this topic at the SuppVersity

Food Gut Interactions

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Sweet But not Innocent?

Sucralose is for Diabetics Not

Stevia: Much More Than Sweet

Sweeter Than Legal

To this ends, the scientists employed a DNA-based pyrosequencing technology to investigate the changes in the intestinal microbiota of piglets weaned to a diet supplemented with either a natural sugar, lactose or said artificial sweetener (SUCRAM)

Figure 1: Total and lactobacillus OTU4228 concentrations in piglets on hydrolzysate carbohydrate diet without sweeteners, with lactose or SUCRAM diets and corresponding concentration of lactic acid in the caecal contents (Daly. 2014)

As you can see in Figure 1, both, the addition of lactose and the saccharin/NHDC mix lead to dramatical increases in the caecal Lactobacillus population and could well explain the previously reported "pro gut health" effect of SUCRAM in piglets (Vente-Spreeuwenberg. 2004; Pierce. 2006)

But that's obviously not all that's news-worthy!

I did after all promise you news on products you may be using, as well - aspartame and acesulfame-k, to be precise. Now, while the former is a constant target of public (mostly broscientific) criticism, the latter has been a thorn in my side ever since I have started investigating artificial sweeteners.

Lean more about the "Gut Type Diet" - No Fad, Guaranteed!

And while previous studies only suggested that the effects of acesulfam-k on the pancreas could have pro-obesogenic consequences, a recent model experiment from the Louisiana State University appears to finally prove that acesulfam-k may actively promote the deposition of body fat in the presence of insulin resistance.

Ok, the results have been derived in a Caenorhabditis elegans, a "worm", but one that has long and actually surprisingly successfully been used as a "model for studying the basic biology of obesity" (Jones. 2009) - I know, I am not convinced either, but if the results do actually translate to humans, this would be major (bad) news for the food industry.

In view of the fact that most companies have been pulling acesulfame-k from their products over the past years, anyway, I would not discard the findings Jolene Zheng et al. present in their latest paper in Chemico-Biological Interactions as meaningless, not despite, but rather because a scientists from PepsiCo was part of the research team which observed these significant increases in intestinal fat (=visceral fat of the worm) when the critters were fed with acesulfam-k sweetened coke.

Cheating? Why would be using artificial sweeteners cheating? In spite of the fact that there is no credible evidence for a causal relationship between the consumption of artificially sweetened foods and obesity (there is a correlation that could well be the result of reverse causation), there is some concerning evidence that the extreme sweet taste and the way people appear to escalate the dosages reduce your bodies ability to control its energy balance by thwarting with its mostly sugar-based first-line energy intake sensor.

What I would not recommend either, though, is to (ab-)use aspartame-containing diet coke as a "weight loss beverage": It's certainly ok to sooth your sweet tooth, when you're dieting and I am not saying that you must not drink one or another Diet Coke or Pepsi on the weekend. What I am saying, though, that I don't believe that the consumption of copious amounts of this stuff will result in a similar body fat reduction (see Figure 2) in you, where compensatory mechanisms, your sweet tongue and a whole host of other things complicate weight and even more so fat loss compared to C. elegans.

That being said, I would be inclined to know, when and if SUCRAM is going to be available as a food additive for humans. It does after all sound quite nice to do your tummy a favor while you're "cheating", right? Although,... when I come to think about it, we actually don't need a "new" sweetener to mess up our gut microbiome. As I already hinted at in a related SuppVersity Classic Article Series with the telling title "Sucralose, Hazardous or Innocent?" (Part I, Part II, Part III), Payne et al.  (2012) have already identified fructose, mannitol and d-tagatose as promoters of lactobacillus growth and sucrose as their primary enemy (learn more about the interaction in Part II of the series).

References: 

• Payne, A. N., C. Chassard, and C. Lacroix. "Gut microbial adaptation to dietary consumption of fructose, artificial sweeteners and sugar alcohols: implications for host–microbe interactions contributing to obesity." Obesity Reviews 13.9 (2012): 799-809.
• Pierce, K. M., et al. "The effect of lactose and inulin on intestinal morphology, selected microbial populations and volatile fatty acid concentrations in the gastro-intestinal tract of the weanling pig." ANIMAL SCIENCE-GLASGOW THEN PENICUIK- 82.3 (2006): 311.
• Jones, Kevin T., and Kaveh Ashrafi. "Caenorhabditis elegans as an emerging model for studying the basic biology of obesity." Disease models & mechanisms 2.5-6 (2009): 224-229.
• Vente-Spreeuwenberg, M. A. M., et al. "Effect of dietary protein source on feed intake and small intestinal morphology in newly weaned piglets." Livestock Production Science 86.1 (2004): 169-177.