Running with Trillions: Gut Microbiome’s Influence on Athletic Performance

May 28, 2023

Picture the human gut as a lively city, home to microorganisms crucial to our health, including vitamin absorption, digestion, and immunity. Recent research hints at a symbiotic relationship between physical activity and this gut microbiome, raising the exciting prospect of enhancing athletic performance by tweaking it. This review uncovers current evidence and potential future developments in this burgeoning field.


Diving into the Microbiome

Our gut houses about 40 trillion microbial cells, our gut microbiome. Advanced technologies reveal these micro-dwellers as diligent workers, aiding in digestion, immune defense, and more. Research on the human microbiome has surged over the last decade, illustrating that our diet, age, and medications influence it.

The gut microbiome’s adaptability presents a golden opportunity for boosting health and performance. While it’s generally stable, specific triggers can cause drastic shifts impacting our health.

Athletes have now entered this microbial scene. There’s growing interest in the potential role of the gut microbiome in improving athletic performance. Although we lack a solid playbook for athlete-specific microbiome modifications, the future holds promise for tapping into the power of the gut microbiome in sports science.


Exercise, the Gut, and Microbiome: A Delicate Balance

The impact of exercise on gut health swings both ways. While moderate exercise can enhance gut health and reduce inflammation, intense and prolonged activity may cause negative effects. For example, endurance athletes often report gut issues during intense sessions, leading some to abandon races. Conversely, inactive individuals have been found to have higher serum endotoxin levels than trained athletes, underscoring the positive influence of exercise on gut health.

Intense exercise can lead to ‘intestinal ischaemia,’ which increases gut inflammation and permeability, potentially causing severe issues. But new evidence also implicates the gut microbiome in these problems. Specifically, some studies suggest that consuming probiotics before a race can help athletes avoid gut discomfort and infections. As we understand this relationship better, harnessing the gut microbiome could become a critical part of sports nutrition.


Gut Microbiomes Influence on Athletic Performance
Gut Microbiomes Influence on Athletic Performance


The Interplay of Microbiome, Respiratory Illnesses, and Inflammation

Elite athletes’ intense training can unfortunately make them more prone to upper respiratory tract infections (URTIs) and gastrointestinal problems, which can disrupt training and performance. Here’s where probiotics come in – they’re not just great for gut health but can also help safeguard against URTIs through immune modulation. Certain strains of probiotics, for example, have significantly reduced URTIs in marathon runners.

Likewise, intense workouts can result in chronic systemic inflammation, causing gastrointestinal discomfort and more. Probiotics again show promise in managing this inflammation, improving health, and potentially enhancing performance. Additionally, they could cut down the need for regular anti-inflammatory medications, which can harm the gut microbiome.

So, incorporating specific probiotics into athletes’ routines could be a powerful strategy for combating URTIs and inflammation, thereby boosting performance.


The Dance Between Gut Health and Athletic Performance

Athletes’ gut microbiomes are quite unique. They’re not only more diverse, but they’re also enriched with health-promoting bacteria, which can help predict and shape their performance. Various types of sports may influence the gut microbiome differently, with those that require more cardiovascular fitness, like long-distance running, showing a higher abundance of beneficial bacteria.


Understanding Gut Microbiome and Athletic Performance: A Focus on Pro-, Pre-, and Synbiotics

The gut microbiome, with its multitude of microorganisms, plays a critical role in our health and has exciting implications for athletic performance. These insights make gut-altering substances like pro-, pre-, and synbiotics a fascinating prospect for sports nutrition.

Probiotics, beneficial bacteria mainly from the Bifidobacterium and Lactobacillus genera, have gained popularity due to their potential to balance gut microbiota, ward off harmful organisms, and stimulate gut immunity. Interestingly, some research has also linked them with enhanced athletic performance, such as improved running endurance and increased swimming endurance and grip strength in mice.

Alongside probiotics, fermented foods, rich in lactic acid bacteria, are gaining attention for promoting a healthy gut microbiome. Preliminary findings suggest they may also aid athletes by reducing post-exercise immune suppression.

Prebiotics, which act as food for our beneficial gut bacteria, can help steer our microbiome’s health. Although research on their effects on athletic performance is scant, early results are promising, particularly for synbiotics (a blend of probiotics and prebiotics). For instance, they have been linked to significant reductions in toxic endotoxins levels in triathlon runners.

Polyphenols, a type of prebiotic, have been highlighted for their antioxidant and anti-inflammatory properties. Some studies suggest they may enhance athletic performance by aiding muscle recovery, reducing fatigue, and decreasing lactate production.

In conclusion, while more research is needed, the potential impact of pro-, pre-, and synbiotics on athletic performance offers intriguing possibilities for sports nutrition, further underscoring the key role of the gut microbiome.

Emerging research has also spotlighted some fascinating findings. For instance, certain probiotics found in fermented cabbage have been linked to improved grip strength and endurance in mice. In marathon runners, a type of bacteria that metabolizes lactate, a compound that builds up during intense exercise, was found in greater quantities.

The gut microbiome also plays a crucial role in energy production, mainly through short-chain fatty acids (SCFAs). These not only serve as an energy source but also help maintain gut health and regulate the immune system. They’re found in higher levels in athletes and are believed to enhance carbohydrate uptake and fat metabolism.

Finally, the gut microbiome plays a part in muscle building and maintenance, notably through its role in protein metabolism. It can boost the availability of amino acids and influence muscle metabolism through certain nutrient-sensitive pathways. So, all in all, the gut microbiome and athletic performance are intricately connected, with future research promising to unlock even more insights for maximizing athletic performance through nutrition and gut health management.


Monitoring the Microbiome Over Time

The gut microbiome, similar to a bustling city, is a dynamic entity. Its monitoring over time allows us to understand how lifestyle changes affect it, which can inform healthier decisions. While some companies offer microbiome profiling, few explore longitudinal trends. A one-time snapshot of the gut microbiome gives limited insights, much like a photo of a city at noon doesn’t represent its different phases. Long-term monitoring, however, can uncover patterns related to recurring conditions like IBD or changes caused by diet modifications and gastrointestinal surgery.

Antibiotics serve as a perfect example of the value of long-term monitoring. They can disrupt gut health, favoring harmful bacteria like Clostridioides difficile. This shift may take up to six months to reverse, with some bacterial strains potentially going extinct, which is crucial information for athletes requiring such treatments.

The gut microbiome’s stability over time also bears significance. A healthy microbiome remains relatively stable, while drastic fluctuations may hint at diseases or health issues. Athletes with stable gut microbiomes have shown better performance improvement after dietary changes. Moreover, athletes experiencing gut distress before travel exhibited more microbiome instability.

Regular microbiome monitoring can be especially beneficial for athletes. Seasonal lifestyle and dietary changes could significantly alter their microbiome, impacting performance. Constant monitoring enables early detection of detrimental changes and subsequent adjustments. Although athletes’ unique lifestyle can negatively affect the gut microbiome, targeted pro-/prebiotic mixes could help rectify imbalances. However, more research is required to formulate effective strategies.

In essence, long-term microbiome monitoring can offer crucial insights into gut health, particularly for athletes, assisting in identifying and remedying negative changes to improve performance.



The Athlete Gut Microbiome and its Relevance to Health and Performance: A Review
Marcus T. O’Brien, Orla O’Sullivan, Marcus J. Claesson & Paul D. Cotter