Among athletes, nutrition plays a key role, supporting training, performance, and post-exercise recovery. Research has primarily focused on the effects of diet in support of an athletic physique; however, the role played by intestinal microbiota has been much neglected. Emerging evidence has shown an association between the intestinal microbiota composition and physical activity, suggesting that modifications in the gut microbiota composition may contribute to physical performance of the host. Probiotics represent a potential means for beneficially influencing the gut microbiota composition/function but can also impact the overall health of the host. In this review, we provide an overview of the existing studies that have examined the reciprocal interactions between physical activity and gut microbiota. We further evaluate the clinical evidence that supports the effects of probiotics on physical performance, post-exercise recovery, and cognitive outcomes among athletes. In addition, we discuss the mechanisms of action through which probiotics affect exercise outcomes. In summary, beneficial microbes, including probiotics, may promote health in athletes and enhance physical performance and exercise capacity. Furthermore, high-quality clinical studies, with adequate power, remain necessary to uncover the roles that are played by gut microbiota populations and probiotics in physical performance and the modes of action behind their potential benefits.

As plant-based diets become more popular, there is an interest in developing innovations to improve the bioaccessibility of plant protein. In this study, seven probiotic strains (Bifidobacterium animalis subsp. lactis B420, B. lactis Bl-04, Lactobacillus acidophilus NCFM, Lacticaseibacillus rhamnosus HN001, Lacticaseibacillus paracasei subsp. paracasei Lpc-37, Lactiplantibacillus plantarum Lp-115, and Lactococcus lactis subsp. lactis Ll-23) were evaluated for their capacity to hydrolyze soy and pea protein ingredients in an in vitro digestion model of the upper gastrointestinal tract (UGIT). Compared to the control digestion of protein without a probiotic, all the studied strains were able to increase the digestion of soy or pea protein, as evidenced by an increase in free α-amino nitrogen (FAN) and/or free amino acid concentration. The increase in FAN varied between 13 and 33% depending on the protein substrate and probiotic strain. The survival of probiotic bacteria after exposure to digestive fluids was strain-dependent and may have affected the strain’s capacity to function and aid in protein digestion in the gastrointestinal environment. Overall, our results from the standardized in vitro digestion model provide an approach to explore probiotics for improved plant protein digestion and bioaccessibility of amino acids; however, human clinical research is needed to evaluate the efficacy of probiotics on amino acid absorption and bioavailability in vivo.

Diets high in red and processed meat and low in plant-based foods are associated with an increased risk of colorectal cancer. We investigated whether berry supplementation can impact gut metabolism to counteract the presumably cancer promoting luminal environment sustained by high red and processed meat consumption. Altogether 43 healthy adults were randomized either into Meat group (150 g/d red and processed pork meat) or Meat & Berries group (150 g/d red and processed meat and 200 g/d of mixed berries). Fecal samples and 3-d food records were collected at baseline and at the end of the four-week intervention. Intakes of vitamin C, vitamin E, manganese, insoluble fiber, and the polyphenols available in the database were significantly higher in the Meat & Berries than Meat group. While between-group comparisons found no significant differences in the gut microbiota, the within-group analyses showed that the relative abundances of beneficial Roseburia and Faecalibacterium were decreased and an unclassified group of Peptostreptococcaceae increased significantly in the Meat group. In comparison to the Meat group, berry consumption resulted in higher fecal concentrations of p-coumaric and protocatechuic acids and lower viability of fecal water (FW) -treated CV1-P fibroblastoma and human colon adenocarcinoma HCA-7 and Caco-2 cells (P<.05 with 30% FW). Berry consumption provided protective nutrients and mitigated potentially unfavourable gut microbiota changes seen in the Meat group, increased fecal polyphenol metabolites, and reduced viability of FW-treated colon adenocarcinoma cells, collectively suggesting that berries may protect against colorectal cancer development.