Does the Intestinal Microbiome Impact Athletic Performance?

Explorative Characterization of GI Complaints, General Physical and Mental Wellbeing, and Gut Microbiota in Trained Recreative and Competitive Athletes with or without Self-Reported Gastrointestinal Symptoms

The current state of the literature lacks a clear characterization of gastrointestinal (GI) symptoms, gut microbiota composition, and general physical and mental wellbeing in well-trained athletes. Therefore, this study aimed to characterize differences in self-reported symptoms, gut microbiota composition, and wellbeing (i.e., sleep quality, mood, and physical (PHQ) and mental wellbeing) between athletes with and without GI symptoms. In addition, we assessed the potential impact of a 3-week multi-ingredient fermented whey supplement in the GI complaints group, without a control group, on the gut microbiota and self-reported GI symptoms and wellbeing. A total of 50 athletes (24.7 ± 4.5 years) with GI issues (GI group at baseline, GI-B) and 21 athletes (25.4 ± 5.3 years) without GI issues (non-GI group, NGI) were included. At baseline, there was a significant difference in the total gastrointestinal symptom rating scale (GSRS) score (24.1 ± 8.48 vs. 30.3 ± 8.82, p = 0.008) and a trend difference in PHQ (33.9 ± 10.7 vs. 30.3 ± 8.82, p = 0.081), but no differences (p > 0.05) were seen for other outcomes, including gut microbiota metrics, between groups. After 3-week supplementation, the GI group (GI-S) showed increased Bifidobacterium relative abundance (p < 0.05), reported a lower number of severe GI complaints (from 72% to 54%, p < 0.001), and PHQ declined (p = 0.010). In conclusion, well-trained athletes with GI complaints reported more severe GI symptoms than an athletic reference group, without showing clear differences in wellbeing or microbiota composition. Future controlled research should further investigate the impact of such multi-ingredient supplements on GI complaints and the associated changes in gut health-related markers.

Integrated physiological, intestinal microbiota, and metabolomic responses of adult zebrafish (Danio rerio) to subacute exposure to antimony at environmentally relevant concentrations

The available information regarding the impact of antimony (Sb), a novel environmental pollutant, on the intestinal microbiota and host health is limited. In this study, we conducted physiological characterizations to investigate the response of adult zebrafish to different environmental concentrations (0, 30, 300, and 3000 µg/L) of Sb over a period of 14 days. Biochemical and pathological changes demonstrated that Sb effectively compromised the integrity of the intestinal physical barrier and induced inflammatory responses as well as oxidative stress. Analysis of both intestinal microbial community and metabolome revealed that exposure to 0 and 30 µg/L of Sb resulted in similar microbiota structures; however, exposure to 300 µg/L altered microbial communities' composition (e.g., a decline in genus Cetobacterium and an increase in Vibrio). Furthermore, exposure to 300 µg/L significantly decreased levels of bile acids and glycerophospholipids while triggering intestinal inflammation but activating self-protective mechanisms such as antibiotic presence. Notably, even exposure to 30 µg/L of Sb can trigger dysbiosis of intestinal microbiota and metabolites, potentially impacting fish health through the "microbiota-intestine-brain axis" and contributing to disease initiation. This study provides valuable insights into toxicity-related information concerning environmental impacts of Sb on aquatic organisms with significant implications for developing management strategies.

What if gastrointestinal complications in endurance athletes were gut injuries in response to a high consumption of ultra-processed foods? Please take care of your bugs if you want to improve endurance performance: a narrative review

To improve performance and recovery faster, athletes are advised to eat more often than usual and consume higher doses of simple carbohydrates, during and after exercise. Sports energetic supplements contain food additives, such as artificial sweeteners, emulsifiers, acidity regulators, preservatives, and salts, which could be harmful to the gut microbiota and impair the intestinal barrier function. The intestinal barrier plays a critical function in bidirectionally regulation of the selective transfer of nutrients, water, and electrolytes, while preventing at the same time, the entrance of harmful substances (selective permeability). The gut microbiota helps to the host to regulate intestinal homeostasis through metabolic, protective, and immune functions. Globally, the gut health is essential to maintain systemic homeostasis in athletes, and to ensure proper digestion, metabolization, and substrate absorption. Gastrointestinal complaints are an important cause of underperformance and dropout during endurance events. These complications are directly related to the loss of gut equilibrium, mainly linked to microbiota dysbiosis and leaky gut. In summary, athletes must be cautious with the elevated intake of ultra-processed foods and specifically those contained on sports nutrition supplements. This review points out the specific nutritional interventions that should be implemented and/or discontinued depending on individual gut functionality.

Nutrient Adequacy in Endurance Athletes

Proper nutrition is critical for optimal performance in endurance athletes. However, it is unclear if endurance athletes are meeting all their energy and nutrient needs. We examined if endurance athletes are meeting their nutritional requirements and if this differed by sex. Ninety-five endurance athletes (n = 95; 50.5% men; 34.9 ± 12.9 y) participated in the study. Dietary intake was evaluated using the 24 h dietary recall method. Energy and nutrient intakes were calculated using the ESHA Food Processor Diet Analysis Software and compared against reference nutrient intakes. Endurance athletes did not consume the recommended amount of energy (76.8% of athletes), carbohydrates (95.8%), linoleic acid (75.8%), α-linolenic acid (ALA) (77.9%), eicosatetraenoic and docosahexaenoic acid (96.8%), dietary fiber (49.5%), vitamins D (93.7%), E (71.6%), and K (54.7%), folate (54.7%), pantothenic acid (70.5%), biotin (83.2%), manganese (58.9%), magnesium (56.8%), chromium (91.6%), molybdenum (93.7%), choline (85.3%), and potassium (56.8%), and consumed too much saturated fat (50.5%) and sodium (94.7%) than recommended. Fisher's Exact test showed that the requirements for dietary fiber (70.8% vs. 27.7%), ALA (87.5% vs. 68.1%), and total water (70.8% vs. 44.7%) were not met by more men versus women (p < 0.05). The needs for protein (70.2% vs. 25%) and vitamin B12 (46.8% vs. 22.9%) were not met by more women compared to men (p < 0.05). These findings need to be confirmed by a larger study.

Fecal microbiota monitoring in elite soccer players along the 2019-2020 competitive season

Physical exercise affects the human gut microbiota that, in turn, influences athletes' performance. The current understanding of how the microbiota of professional athletes changes along with different phases of training is sparse. We aim to characterize the fecal microbiota in elite soccer players along with different phases of a competitive season using 16S rRNA gene sequencing. Fecal samples were collected after the summer off-season period, the pre-season retreat, the first half of the competitive season, and the 8 weeks COVID-19 lockdown that interrupted the season 2019-2020. According to our results, the gut microbiota of professional athletes changes along with the phases of the season, characterized by different training, diet, nutritional surveillance, and environment sharing. Pre-season retreat, during which nutritional surveillance and exercise intensity were at their peak, caused a decrease in bacterial groups related to unhealthy lifestyle and an increase in health-promoting symbionts. The competitive season and forced interruption affected other features of the athletes' microbiota, i.e. bacterial groups that respond to dietary fibers load and stress levels. Our longitudinal study, focusing on one of the most followed sports worldwide, provides baseline data for future comparisons and microbiome-targeting interventions aimed at developing personalized training and nutrition plans for performances maximization.

Hiding in Plain Sight: Factors Influencing the Neuroinflammatory Response to Sport-Related Concussion

Sport-related concussion (SRC) is a major concern among athletes and clinicians around the world. Research into fluid biomarkers of SRC has made significant progress in understanding the complex underlying pathophysiology of concussion. However, little headway has been made toward clinically validating any biomarkers to improve the clinical management of SRC. A major obstacle toward clinical translation of any fluid biomarker is the heterogeneity of SRC overlapping with multiple physiological systems involved in pathology and recovery. Neuroinflammation post-SRC is one such system that may confound fluid biomarker data on many fronts. Neuroinflammatory processes consist of cell mediators, both within the central nervous system and the periphery, that play vital roles in regulating the response to brain injury. Further, neuroinflammation is influenced by many biopsychosocial variables present in most athletic populations. In this commentary, we propose that future fluid biomarker research should take a systems biology approach in the context of the neuroinflammatory response to SRC. We highlight how biological variables, such as age, sex, immune challenges, and hypothalamic-pituitary-adrenal (HPA)-axis responses to stress, may alter neuroinflammation. Further, we underscore the importance of accounting for health and lifestyle variables, such as diet, exercise, sleep, and pre-morbid medical factors, when measuring inflammatory markers of SRC. To successfully move toward clinical translation, fluid biomarker research should take a more holistic approach in study design and data interpretation, collecting information on hidden variables that may be influencing the neuroinflammatory response to SRC.

PROBIOTIC SUPPLEMENTS FOR ENDURANCE EXERCISE PERFORMANCE AND IMMUNE FUNCTION

ABSTRACT Introduction: After long-term research, it was found that athletes are susceptible to suffering from upper respiratory tract infections and digestive system diseases when subjected to high-intensity exercise for long periods. Objective: To verify whether consuming probiotic supplements after exercise can significantly improve the function of the immune system and play a positive role in the health of athletes. Method: This is a quantitative study with distribution analysis to verify whether probiotic supplements could improve immune response after exercise. Results: After using probiotic supplements, by recording the individual differences in the distribution characteristics of athletes› gastrointestinal flora, we found that the changes of subjects› sports performance, leukocytes, neutrophils, lymphocytes, and gastrointestinal flora after six weeks of special training were different. Conclusion: Long-term oral probiotics for athletes can effectively reduce inflammation in the body, reduce damage to the body during exercise, and effectively improve the gastrointestinal tract›s immune function. Level of evidence II; Therapeutic studies - investigation of treatment results.

Fueling Gut Microbes: A Review of the Interaction between Diet, Exercise, and the Gut Microbiota in Athletes

The athlete's goal is to optimize their performance. Towards this end, nutrition has been used to improve the health of athletes' brains, bones, muscles, and cardiovascular system. However, recent research suggests that the gut and its resident microbiota may also play a role in athlete health and performance. Therefore, athletes should consider dietary strategies in the context of their potential effects on the gut microbiota, including the impact of sports-centric dietary strategies (e.g., protein supplements, carbohydrate loading) on the gut microbiota as well as the effects of gut-centric dietary strategies (e.g., probiotics, prebiotics) on performance. This review provides an overview of the interaction between diet, exercise, and the gut microbiota, focusing on dietary strategies that may impact both the gut microbiota and athletic performance. Current evidence suggests that the gut microbiota could, in theory, contribute to the effects of dietary intake on athletic performance by influencing microbial metabolite production, gastrointestinal physiology, and immune modulation. Common dietary strategies such as high protein and simple carbohydrate intake, low fiber intake, and food avoidance may adversely impact the gut microbiota and, in turn, performance. Conversely, intake of adequate dietary fiber, a variety of protein sources, and emphasis on unsaturated fats, especially omega-3 (ɷ-3) fatty acids, in addition to consumption of prebiotics, probiotics, and synbiotics, have shown promising results in optimizing athlete health and performance. Ultimately, while this is an emerging and promising area of research, more studies are needed that incorporate, control, and manipulate all 3 of these elements (i.e., diet, exercise, and gut microbiome) to provide recommendations for athletes on how to "fuel their microbes."