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There is a lot of information out there about “gut health,” or the gut microbiome, and how that affects our health. This topic is of particular interest to endurance athletes, since the gut microbiome has a significant effect on sports performance.


First of all, what is the gut microbiome? It is the billions of microbial cells in the gut that affect the immune system, digestion, nutrient absorption, mood regulation, and other aspects of health and athletic performance. Physical activity is very good for the gut microbiome. A few of the benefits are decreased intestinal permeability, lower inflammation and weight maintenance. It is possible that intense and sustained exercise may have some negative effects, but it is well-known that athletes tend to have higher levels of health-associated bacteria in their gut microbiome.


Modifying the gut microbiome to improve sports performance

Studies have shown an increase in certain metrics of sports performance in animals and humans following treatment with probiotics. Probiotic supplements are defined as “live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.”


Another method of influencing the microbiome is with prebiotics, which are defined as “a substrate that is selectively utilized by host microorganisms conferring a health benefit.” This consists of dietary fiber that cannot be easily directly digested by humans and thus serves to feed certain bacteria in the intestines with a favorable effect on health. Research on the effects of prebiotics on athletic performance is rather limited and has so far largely focused on symbiotic supplements, which are a combination of probiotics and prebiotics.


Potential effects of the gut microbiome on sports performance

Modulating the gut microbiome has the potential to improve athletic performance in several ways:

1. Protect against gastrointestinal disorders and upper respiratory tract infections (URTIs)

2. Improve VO2 max

3. Increase muscle mass

4. Increase motivation to exercise

5. Reduce inflammation

6. Improve body composition

7. Improve nutrient absorption

8. Improve sleep


How to optimize your gut microbiome

The best thing to do is to optimize the diversity of your gut bacteria by adopting a balanced diet, high in fiber, and with as much variety as possible. Fibers are found in plant-based whole foods: fruits, vegetables, whole grains, nuts, seeds and legumes. It is recommended to eat at least 30 different plants per week.


It is also important to limit saturated fats, which are associated with a pro-inflammatory composition of the gut microbiome. Saturated fats are found in red meat, fried foods, high fat dairy, butter, tropical oils (coconut oil, palm oil) and processed bakery products. Those should be replaced by unsaturated fats and omega-3s, which promote the production of SCFAs (short-chain fatty acids). Good sources of unsaturated fats include nuts, seeds, avocado and olive oil. Good sources of omega-3s include fatty fish (e.g. salmon, trout, tuna, sardines), ground flax seeds, chia seeds and walnuts.


In conclusion, regular moderate physical activity as well as adopting a varied and balanced diet can help improve gut microbiome and overall health, and contribute to the improvement of sports performance.




Hungry for more information? Here are the references that were used in the writing of this article:


1)    O’Brien et al. (2022) The athlete gut microbiome and its relevance to health and performance: A Review. Sports Medicine; 52 (Suppl 1):S119–S128.

2)    Scheiman et al. (2019). Meta-omics analysis of elite athletes identifies a performance-enhancing microbe that functions via lactate metabolism. Nat Med;25:1104–9.

3)    Shing et al. (2014). Effects of probiotics supplementation on gastrointestinal permeability, inflammation and exercise performance in the heat. Eur J Appl Physiol;114:93–103.

4)    Lee et al. (2020). Subspecies SA-03 is a new probiotic capable of enhancing exercise performance and decreasing fatigue. Microorganisms; 8(4), 545.

5)    Estaki et al. (2016). Cardiorespiratory fitness as a predictor of intestinal micro- bial diversity and distinct metagenomic functions. Microbiome;4:42.

6)    Valentino et al. (2021). Dysbiosis of the gut microbiome impairs mouse skeletal muscle adaptation to exercise. J Physiol; 599(21): 4845-63.

7)    Dohnalova et al. (2022) A microbiome-dependent gut–brain pathway regulates motivation for exercise. Nature; 612 (7941):739-747.

8)    Diener et al. (2021) Baseline Gut Metagenomic Functional Gene Signature Associated with Variable Weight Loss Responses following a Healthy Lifestyle Intervention in Humans. mSystems 6:e00964-21.

9)    Hughes and Holscher (2021) Fueling Gut Microbes: A Review of the Interaction between Diet, Exercise, and the Gut Microbiota in Athletes. Adv Nutr; 12:2190-2215.

10)  Han, Yuan and Zhang (2022) The interplay between sleep and gut microbiota. Brain Res Bull;180:131-146. 

11) Hugues (2020) A Review of the Role of the Gut Microbiome in Personalized Sports Nutrition. Front Nutr;6:191.

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