No Guts, No Glory – 9 Ways The Gut Microbiome Impacts Athletic Performance


What if, one day, athletes could inoculate themselves with microscopic organisms that made them run faster, jump higher, and recover quickly like a comic book superhero? 

Sounds like a Marvel movie, doesn't it?

But what if we told you that every athlete is already covered in microbes living in and on them, which could give them an edge over their competition? 

There are trillions of bacteria, viruses, and fungi living in and on every living person, existing in multiple microbial ecosystems throughout the body called microbiomes. When it comes to athletes, their gut bacteria significantly influence how well they perform and how fast they recover. 

The microbes in our gut are responsible for the way in which we break down fiber, carbohydrates, protein, and regulate energy.1 They influence inflammation, stress resilience, and neurological function, even impacting mental toughness – all of which are incredibly important to athletic performance.2

The fundamental role our microbes play in energy regulation and athletic recovery has researchers exploring questions like:

  • Could microbiome genomics help us predict the next Michael Jordan, Michael Phelps, Simone Biles, or Serna Williams?

  • Can we harvest the microbes of professional athletes to pass on high-performing microbial capabilities?

  • Will we one day be able to purchase “performance probiotics?”

While no one can possibly predict the end result of these findings, the implications are thrilling. 

Harvard Researchers Find ‘Elite Gut Microbiota’

Imagine a world where you could mimic Michael Jordan's gut microbiome to improve your athletic abilities. What if you could jump higher, run faster, and outlast the competition with a Michael Jordan probiotic? This may sound like it came straight out of a sci-fi novel, but take a look at research, it suggests that this might actually be a possibility. 

Athletic performance, recovery, and even the type of sport athletes play have been linked to certain microbes colonizing the gut. These findings now have researchers looking for ways to increase the specific organism for better performance and faster recovery.

In one study, a group of Harvard researchers sampled the gut microbiomes of athletes training for the Boston Marathon. After the marathon, they found a spike in one species of bacteria that breaks down lactic acid, which floods muscles after intense exercise. These scientists believe the up-regulation of this particular bacteria is a response to the increased lactic acid levels in the body because it’s their food source.3 This begs the question—could this species be used to reduce lactic acid buildup and speed up recovery time?

In another study, Harvard researchers compared the gut microbiomes of rowers and ultramarathoners. They found clear differences in microbial composition, which suggests that certain sports may foster the growth of specific microbes.2

Maybe this is perhaps why Michael Jordan couldn’t quite succeed in the world of baseball the way he did in basketball – he just didn’t have the microbes for it. 

You probably aren't surprised to hear that the scientific findings have led to the quest for performance-based prebiotics and probiotics.2 What's even more interesting is that some scientists believe they will be able to mine the gut microbiomes of ultra-athletes to help others. 

It’s undeniable that the gut microbiome has an impact on athletic ability. Exercise also has the ability to alter the gut microbiome – making this relationship a two-way street.4 

Exercise Can Strengthen the Gut Microbiome

Though diet is the most influential factor in determining which microbes are in your gut, environmental factors play a role, too. Exercise is an important environmental factor shown to positively affect the gut microbiome – but only if it’s not excessive. 

Specifically, moderate exercise:4

  • Enriches microbiota diversity – This is important for signaling along the brain-gut access and body homeostasis.

  • Improves the Bacteroides to Firmicutes ratio – This helps maintain healthy weight and reduces risk for obesity-related conditions.

  • Stimulates bacteria known to improve gastrointestinal lining barrier functions –  Which can help fight obesity and metabolic diseases. 

  • Stimulates bacterial activities beneficial to human health – Some protect against gastrointestinal disorders and colon cancer. 

In case you need another motivator to get up and go for a run, here it is: Exercise can improve the health of your gut microbiome, which may make it easier for you to stay lean and healthy overall

However, like so many things in life, you can have too much of a good thing. In the case of exercise, regular overexertion appears to harm the health of the gut microbiome, so it’s all about finding balance.  

Extreme Exercise Can Wreck the Gut Microbiome

Extreme physical exercise can cause dysbiosis—an imbalance of the gut microbiome—which can negatively impact overall health. In some cases, overexercising could cause more harm than good.

Ultra-athletes put incredible demands on their body when they train, both physiologically and biochemically. The demand not only elicits responses from the muscles but across the entire body and can result in systemic reactions. When an elite athlete repeatedly exposes their body to these drastic physiological circumstances, it can disrupt the body’s homeostasis, overwhelm the organs, and affect normal function.5

Gut microbiome composition lies on a spectrum, with sedentary lifestyle microbes at one end and ultra athlete’s microbes at the other end. The key is to exercise in a way that’s ideal for your health, meaning finding the right place on the gradient for you and your gut microbiome. Finding this takes personal experimentation. 

If you aren’t a professional athlete but exercise regularly, chances are your workouts aren’t having a dramatically negative impact on your gut microbiome. 

9 Ways the Gut Microbiome Impacts Athlete Performance

While it’s a lot of fun to fantasize about all the different ways this science could play out in the future, we’re still left with the question…

How does the gut microbiome actually impact athletic performance? 

To answer this question accurately, we have to examine exactly what the science tells us. So, let’s dig a little deeper into the nitty gritty behind this question. For all you fitness nerds out there, you’re going to love this. 

1. Reducing Inflammation

The gut microbiome plays a significant role in inflammation – either increasing or decreasing levels. Inflammation interferes with athletic performance, slows recovery, and is the root cause of many chronic diseases. Gut microbiome imbalance, or dysbiosis, is associated with inflammatory conditions – so it’s important we maintain a healthy microbiome to help reduce bodywide inflammation.6

Research shows that improving your microbiome balance reduces systemic inflammation, which provides both short-term relief and long-term risk reduction.6 A balanced and diverse microbiome also provides a more stable environment, which reduces the impact of the repeated stress athletes place on their bodies.

When it comes to inflammation, the gut microbiome can either work for you or against you. In the case of ultra athletes, they may be unknowingly optimizing their gut microbiome through experimentation OR causing chaos when they overtrain. 

2. Boosting Energy Levels

When your gut microbiome is happy and healthy, it helps boost energy levels, which can translate into better performance by:

  • Reducing fatigue through better lactic acid breakdown.7

  • Controlling redox function, which can delay fatigue symptoms.8

  • Increasing ATP levels, your cell’s energy source.9

  • Modulating metabolism.4

  • Supplying essential metabolites to your mitochondria – your cell’s powerhouse.9

  • Regulating energy harvest, storage, and expenditure.4

Athletes rely on their high energy levels to launch themselves past their competitors and beyond. They must have a gut microbiome that operates at peak performance if they want to stand a chance. 

3. Improving Mental Strength

You might be surprised to hear this, but your gut microbes talk to your brain along the vagus nerve. They have a huge role in the state of your mental health, and when they are imbalanced, they can contribute to mental illness. Dysbiosis (gut microbiome imbalance) has even been linked to anxiety and depression. 

On the flip side, a healthy gut microbiome composition can contribute to mental strength. The composition of the gut microbiome significantly affects:3

  • Mood

  • Pain tolerance

  • Cognitive performance

  • Behavior

  • Mental clarity

  • Attitude 

  • Brain function

The gut-brain axis is an invisible hand that shapes mental fortitude, which is essential for professional athletes who can’t afford to buckle under pressure.

4. Shaping Ideal Body Composition

There aren’t too many overweight high-level athletes – well, maybe in sports like football, where many players are technically obese if you are only looking at their BMI. But when it’s an activity that relies on strength and speed, the gut microbiome helps the body run more efficiently – like a well-oiled machine. So, when the gut microbiome is in good shape, it can make being healthier easier. This is because the gut microbiome influences:10

  • Body mass composition (muscle vs. fat)

  • White vs. brown fat

  • Blood glucose response to meals

Every athlete knows just how important these factors are to overall performance. Now we know that the gut microbiome plays a huge role in each, making it the new focus of forward-thinking training regimens. 

5. Strengthening Bones

The microbiome helps build bone mass and strength through hormone and immune system regulation. A balanced gut microbiota can also increase mineral absorption of calcium and magnesium. This is especially good news in times of injury because a properly functioning microbiome can speed up bone healing during sport-related trauma.11

So, forget about drinking enough milk for stronger bones – you’d be much better off making sure you’re eating the right foods for your gut microbiome to support optimal bone metabolism. 

6. Nutrient Absorption & Use

One of the main takeaways about the gut microbiome should be that when it runs efficiently, the whole body runs efficiently. This is why scientists are so interested in mapping athletic gut microbiomes and using them to improve the health of others. 

Due to this fact, it’s no surprise that a balanced microbiome is essential for proper absorption and use of nutrients.12  If you have a toxic gut microbiome, then the microbes are fighting just to survive and don’t have time or energy to produce enzymes to pull out important vitamins and minerals from the food you eat – they’re just hanging on for dear life. 

A healthy gut microbiome is essential to any athlete interested in getting the most out of their food. What use is it to train hard and eat right if your microbes can’t extract critical nutrients?

When you eat the right foods for your microbial digestive machine, it can pull out maximum nutrients, resulting in bonus results. 

What’s more, the gut microflora actually synthesizes a lot of your needed nutrients. They take food your digestive tract can’t process and transform it into nutrients you need to survive.12  As you can imagine, it’s ideal for athletes to have gut microbiomes that are thriving.

7. Elevating Hydration Status

Elevating hydration status sounds super official, doesn’t it? It’s just a fancy way of saying that the gut microbiome has been linked to hydration regulation during exercise. Meaning, your body is using water efficiently. Also, the integrity of the gut lining is a key factor in proper hydration, which a healthy gut microbiome also helps maintain.13

8. Improving Sleep

Gut microbiome imbalance, or dysbiosis, is associated with poor sleep quality and lowered cognitive flexibility. This is because the gut microbiome controls levels of various hormones such as cortisol, serotonin, and GABA – all of which affect sleep quality.14 The microbiome also affects the production of melatonin – essential for proper sleep-wake cycles.15

Quality sleep, good gut health, energy levels, and performance all exist in a reinforcing cycle that can either compound on one another and build you up – or drag you down. Athletes know they need proper sleep to perform well, but many might not yet realize that there’s a pharmacy of sleep-promoting neurotransmitters generated by their gut. 

9. Antioxidant Defense System 

Your body has an impressive system called the antioxidant defense system, or redox signaling that uses antioxidant enzymes to keep you healthy.16 Athletes need this system to consistently perform well and recover in record time, keeping them at the top of their game. 

A healthy redox status is associated with a balanced gut microbiome. This gut microbiome-regulated antioxidant enzyme system:8,16

  • Prevents tissue damage from exercise

  • Protects against intense exercise-induced oxidative damage 

  • Is associated with the physical status of athletes

  • Reduces physical fatigue 

  • Improves exercise performance

In general, intensive and sustained exercise training and high-level competition generate large amounts of free radicals that likely exceed the buffering capacity of a typical body. This makes athletes susceptible to oxidative stress and more likely to build up damaging inflammation. 

The Future of Gut Microbiome Science is the Future of Performance Science

At this point, you’re probably wondering what you can do to improve the health of your gut microbiome and gain an edge over your competition. One of the best steps you can take right now is working to improve your gut microbiome diversity. 

A diverse gut microbiome is a healthy gut microbiome. 

Eating a healthy diet that is diverse in foods is a good start. But you can take this to the next level when you eat a diet individualized to your gut microbiome. And that’s where Viome comes in. With one test, you can discover the best foods and supplements that your body needs right now for better health. See for yourself! 


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