Changes in the Gut Bacteria Composition of Healthy Men with the Same Nutritional Profile Undergoing 10-Week Aerobic Exercise Training: A Randomized Controlled Trial.

Nutrient consumption and body mass index (BMI) are closely related to the gut microbiota, and exercise effects on gut bacteria composition may be related to those variables. Thus, we aimed to investigate the effect of 10-week moderate aerobic exercise on the cardiorespiratory fitness and gut bacteria composition of non-obese men with the same nutritional profile. Twenty-four previously sedentary men (age 25.18 [SD 4.66] years, BMI 24.5 [SD 3.72] kg/m2) were randomly assigned into Control (CG; n = 12) or Exercise Groups (EG; n = 12). Body composition, cardiorespiratory parameters, blood markers, dietary habits and gut bacteria composition were evaluated. EG performed 150 min per week of supervised moderate (60-65% of VO2peak) aerobic exercise, while CG maintained their daily routine. The V4 16S rRNA gene was sequenced and treated using QIIME software. Only EG demonstrated marked improvements in cardiorespiratory fitness (VO2peak, p < 0.05; Effect Size = 0.971) without changes in other gut bacteria-affecting variables. Exercise did not promote clustering based on diversity indices (p > 0.05), although significant variations in an unclassified genus from Clostridiales order and in Streptococcus genus were observed (p < 0.05). Moreover, α-diversity was correlated with VO2peak (Pearson's R: 0.47; R2 0.23: 95%CI: 0.09 to 0.74, p = 0.02) and BMI (Pearson's R: -0.50; R2 0.25: 95%CI: -0.75 to -0.12, p = 0.01). Roseburia, Sutterella and Odoribacter genera were associated with VO2peak, while Desulfovibrio and Faecalibacterium genera were associated with body composition (p < 0.05). Our study indicates that aerobic exercise at moderate intensity improved VO2peak and affected gut bacteria composition of non-obese men who maintained a balanced consumption of nutrients.

Probiotic supplementation in marathonists and its impact on lymphocyte population and function after a marathon: a randomized placebo-controlled double-blind study.

Probiotic supplementation arises as playing an immune-stimulatory role. High-intensity and -volume exercise can inhibit immune cell function, which threatens athletic performance and recovery. We hypothesized that 30 days of probiotic supplementation could stabilize the immune system of athletes preventing immune suppression after a marathon race. Twenty-seven male marathonists were double-blinded randomly into probiotic (Bifidobacterium-animalis-subsp.-Lactis (10 × 109) and Lactobacillus-Acidophilus (10 × 109) + 5 g of maltodextrin) and placebo (5 g of maltodextrin) group. They received 30 sachets and supplemented 1 portion/day during 30 days before the race. Blood were collected 30 days before (rest), 1 day before (pre), 1 h after (post) and 5 days after the race (recovery). Both chronic and acute exercise modulated a different T lymphocyte population (CD3+CD4-CD8- T-cells), increasing pre-race, decreasing post and returning to rest values at the recovery. The total number of CD8 T cell and the memory subsets statistically decreased only in the placebo group post-race. Pro-inflammatory cytokine production by stimulated lymphocytes decreased in the probiotic group after the supplementation period. 30 days of probiotic supplementation maintained CD8 T cell and effector memory cell population and played an immunomodulatory role in stimulated lymphocytes. Both, training and marathon modulated a non-classical lymphocyte population regardless of probiotic supplementation.

Probiotics and sports: A new magic bullet?

The use of probiotics in sports has been growing in the past years focusing on the attenuation of upper respiratory tract (URS) and gastrointestinal (GI) symptoms commonly present in endurance athletes. Researches shown different results and this may related to the probiotic strain, dose, period consumption or even the form of administration (capsules, sachets or fermented milk). These four factors directly influence in the probiotic's outcome and this question still remains unclear. Thus, the goal of this review is to clarify how these factors may influence the outcomes, approaching the major differences among studies, mechanisms by which the probiotic may contribute in sports field and applied conclusions. It was used 'probiotics', 'athletes', 'sports', 'exercise', 'athletes performance', 'immune response', 'intestinal symptoms' as keywords and its combinations and 20 original articles were selected for our purpose. All the articles were performed in healthy physically active people and/or athletes. Putting together, it was observed that athletes may benefit from probiotics consumption. It seems that multi strain ingested via sachet or fermented food and a larger period of consumption may shown better results at minimizing URS and GI symptoms. Also, specific species appears to have a role in exercise recovery. Therefore, the beneficial effect of probiotics in sports field is strictly dependent on the four factors abovementioned. The molecular mechanisms behind the probiotics effectiveness have not yet been elucidated and perhaps the biological assessments performed in the studies as well the few number of studies published did not answer the question yet.