Morinaga Milk probiotic may ease digestive issues linked to high-protein diets
Key takeaways
- Morinaga Milk’s joint study suggests Bifidobacterium longum BB536 may help improve diarrhea-related QOL scores in male athletes consuming high-protein diets.
- Findings indicate BB536’s effects may depend on gut microbiota composition.
- The probiotic may also reduce body-odor-related metabolites in certain enterotypes, pointing to more personalized sports nutrition applications.

Morinaga Milk Industry has released joint research findings together with Japan-based scientists to investigate the effects of Bifidobacterium longum BB536 consumption in male athletes following a high-protein diet. These diets may disturb the gut environment and increase body-odor-related metabolites production, such as gases, sweat, and other body smells.
Under such dietary distress, probiotic supplementation has been proposed to support gut health, and the new findings suggest that BB536 may improve diarrhea-related quality-of-life (QOL) scores and reduce body-odor-related metabolites production.
The study was conducted together with professor Shuichi Machida of the Graduate School of Health and Sports Science at Juntendo University and professor Daisuke Asaoka of the Juntendo Tokyo Koto Geriatric Medical Center.
“The results of this study point to the potential of personalized nutritional approaches based on differences in gut microbiota composition within the unique dietary context of athletes. As this was an exploratory study, we will continue to conduct further studies and advance the research and development of probiotics aimed at maintaining athletes’ health and improving their QOL,” says Morinaga Milk.
The findings have been published in the Journal of the International Society of Sports Nutrition.
Probiotics for high-protein
The study found improvements in diarrhea-related QOL scores following ingestion of BB536. The participants with improved scores also had an increased abundance of the butyrate-producing genus Faecalibacterium.
The effect of body-odor-related metabolites was shown to be dependent on the person’s type of gut microbiome. Probiotics are known for improving the gut environment, but research on athletes following a high-protein diet is limited, notes Morinaga Milk.
Excessive protein intake disrupts the gut environment, notes the study.Excessive protein intake disrupts the gut environment, gastrointestinal symptoms, and increases metabolites that contribute to body odor.
This randomized, double-blind, placebo-controlled, parallel-group trial included 60 male athletes. For four weeks, the men received either a placebo or a capsule containing BB536. Both groups consumed 70 g of whey protein daily.
There was no significant difference observed between groups, but the capsule group showed a within-group improvement in diarrhea-related QOL scores after four weeks. The men who experienced these improved scores also had increased levels of Faecalibacterium when compared to those who did not see improvements.
Morinaga Milk says that these findings suggest that the improvement effect of BB536 on diarrhea-related QOL scores may depend on the composition of the gut microbiota.
Differences between microbiomes
To further investigate how the differences in the participants’ gut microbiota were influenced by BB536 on body-odor-related metabolites, the men were classified into two enterotypes — a concept used to classify patterns in the gut microbiota composition.
The classification was done on their gut microbiota composition before the study intervention took place.
The participants were divided into R-type — Ruminococcus-dominant or F-type — Faecalibacterium-dominant microbiomes.
The study found that the R-type participants were associated with a trend toward increased propionic acid and a significant increase in butyric acid. Meanwhile, the F-type group was associated with a trend of decreased ammonia and a significant decrease in methyl mercaptan.
“These findings suggest that the effect of BB536 on body-odor-related metabolites may depend on enterotype, and that in the F-type in particular, BB536 may act to reduce body-odor-related metabolites in athletes consuming a high-protein diet,” notes the company.













