The athletic gut microbiota

Abstract

The microorganisms in the gastrointestinal tract play a significant role in nutrient uptake, vitamin synthesis, energy harvest, inflammatory modulation, and host immune response, collectively contributing to human health. Important factors such as age, birth method, antibiotic use, and diet have been established as formative factors that shape the gut microbiota. Yet, less described is the role that exercise plays, particularly how associated factors and stressors, such as sport/exercise-specific diet, environment, and their interactions, may influence the gut microbiota. In particular, high-level athletes offer remarkable physiology and metabolism (including muscular strength/power, aerobic capacity, energy expenditure, and heat production) compared to sedentary individuals, and provide unique insight in gut microbiota research. In addition, the gut microbiota with its ability to harvest energy, modulate the immune system, and influence gastrointestinal health, likely plays an important role in athlete health, wellbeing, and sports performance. Therefore, understanding the mechanisms in which the gut microbiota could play in the role of influencing athletic performance is of considerable interest to athletes who work to improve their results in competition as well as reduce recovery time during training. Ultimately this research is expected to extend beyond athletics as understanding optimal fitness has applications for overall health and wellness in larger communities. Therefore, the purpose of this narrative review is to summarize current knowledge of the athletic gut microbiota and the factors that shape it. Exercise, associated dietary factors, and the athletic classification promote a more "health-associated" gut microbiota. Such features include a higher abundance of health-promoting bacterial species, increased microbial diversity, functional metabolic capacity, and microbial-associated metabolites, stimulation of bacterial abundance that can modulate mucosal immunity, and improved gastrointestinal barrier function.

Recent advances in clinical probiotic research for sport

“…Commonly used probiotic strains for the application of exercise include Lactobacillus , Bifidobacterium , and Bacillus genera, however, new microbiome research and technological advances are identifying potential next-generation probiotic candidates [ 4 ]. In the context of exercise, and especially athletes, the present body of literature suggests their microbiota has several key differences in comparison with other populations, likely driven, in part, by exercise and diet [ 5 ▪ ]. These characteristics may influence the effects of probiotics on the resident microbiome and host physiology, as well as consideration for probiotic application.…”

“…However, the recent positive findings noted above are promising and investigators are encouraged to continue this line of research for both macro and micronutrients. It may be that the exercise associated gut microbiota may be more receptive to improved nutrient utilization as it appears to possess a functional capacity that is primed for tissue repair and a greater ability to harness energy from the diet with increased capacity for carbohydrate, cell structure, and nucleotide biosynthesis [ 5 ▪ ].…”

Biomimetic Gut Model Systems for Development of Targeted Microbial Solutions for Enhancing Warfighter Health and Performance

“…Bioinformatics studies have quantitively illustrated how stress can reduce intestinal barrier integrity, altering gut microbiota composition, which in turn modulates immunoregulatory responses in the host (9,40,41). A compromised gut microbiota profile introduces disruption in the uptake of fluids, electrolytes, and vital nutrients, exerting negative impacts on exercise performance and recovery (42)(43)(44). Host-gut microbiota interactions are also implicated in the nervous system control of glucose, impacting another aspect of host metabolic efficiency (45).…”

“…The gut microbiome is highly dynamic and correlated with multiple factors including diet, genetic makeup, stress, socioeconomic status, interactions between social and physical environments (42), and exercise (43). It fluctuates over time (13) and varies biogeographically across different sections of the gut (14).…”

Does simulated microgravity induce significant changes in human gut microbiota? New answers with dry immersion, an innovative ground-based model.

“…Recent research has revealed that the gut microbiota impacts the host physiology and human health [2]. Indeed, the data obtained on earth argue to preserve an optimized gut microbiota composition, as its disruption/deregulation of these bacteria communities referred to as dysbiosis, is associated with health disorders [3] and/or altered physical performance [4][5][6][7][8]. As a modulator of the immune system, the gut microbiota contributes to intestinal homeostasis and integrity (permeability and in ammation) and exerts a nutritional role via its bacteria-derived metabolites [4].…”