Going into the FIBA World Cup in China, Team USA are the favorites, with usual suspects like Argentina and Yugoslavia hot on their heels. But with a cluster of NBA players, Canada is one of the dark horse squads primed to spring a surprise on international basketball’s top seeds. Beyond the talent they can put onto the hardwood, the Canadians have assembled a solid staff behind the scenes to provide an edge on and off the court. One of their secret weapons is Dr. Marc Bubbs, who serves as Performance Nutrition Lead. He is a naturopathic doctor and former strength coach who also consults with professional sports teams in the NBA, NFL, NHL, and MLB. 

Marc recently published one of the most highly anticipated sports science books in years, Peak. In it, he shares evidence-based, competition-tested insights on a wide range of topics, from sleep and circadian rhythms to blood sugars and longevity to periodized recovery. One of the most fascinating sections focuses on gut health. In the first installment of a two-part interview, Marc shared insights about how athletes can improve their gut diversity, the benefits of doing so, and why probiotics don’t have to only come from pills.

// What’s the relationship between gut health and physical performance?

Gut health impacts physical function and athlete health. If you’re catching colds and the flu frequently, that’s incompatible with elite performance. To be at your best, you need to show up and you can’t if you’re ill. We know that around 70 percent of the immune system is rooted in the gut, which also has a strong connection with mindset, mood, and autonomic nervous system function through the vagus nerve. The food you eat can contribute to anxiety and low mood, while overtraining – or, more commonly, under-recovering – can be tied to IBS and other digestive issues.

// Probiotics are a huge growth area in the supplement industry. Can you tell me about how they impact immunity?

Sure. Researchers like Sam Gibbs, David Pyne, and Nick West are at the forefront in this area. Pyne and West did a meta-analysis of probiotic studies and found that those athletes who were taking them reduced the severity and duration of illness. On the other end, probiotics can reduce the incidence of cold and flu. In high level sports, players can get sick at just the wrong time – like during our build up to the FIBA World Cup. There are two factors at work – exposure to pathogens and a depressed or compromised immune system. While probiotics can help with the latter, there’s a lag time between when you start taking them and when they kick in. So if you’re getting ready to travel, you should start probiotic supplementation two or three weeks beforehand. 

We also try to go back to basics and identify other factors. For example, hand-to-hand contact is a big one for going from one guy being sick on the first day of camp to two or three reporting to the team doctor on day two, and so on. So we reiterate that the players should only fist bump rather than shaking hands or high-fiving. Then we encourage them to wash their hands, which can reduce the risk of getting the flu or a cold by 40 percent.

// What kinds of probiotics do you recommend, and does it matter when athletes take them?

There’s a lot of individualization in each person’s microbiome and different strains do different things. But that being said, there are some keystone bacteria that help keep many others in line. Bifodobacteria help digest fiber, support immunity, and aid nutrient absorption. They’re naturally found in dairy, but with more athletes moving away from this food group, bifodbacterium longum can be a useful supplement. You could look for a multi-strain probiotic that also contains lactobacillus rhamnosus, L. fermentum, B.infantis, and L. casei, all of which have studies to back up their efficacy. I believe the strains are more important than the number of CFUs. There are over a trillion bacteria in the human gut, so even 50 billion CFUs is a drop in the bucket. 

In terms of when athletes start taking probiotics, I recommend starting supplementation during pre-season to get used to them before the competitive schedule starts. They can also provide extra support if the team is flying, during peak season, and when the schedule gets hectic. And you don’t have to stay on probiotics forever – in an ideal situation you should still have a healthy gut if you take them away.

// Can exercise impact gut health?

We’re seeing more and more research that shows the link between physical fitness, a healthy diet, and the microbiome. Lauren Petersen and her colleagues did a study and found that a sedentary group who ate poorly and took amoxicillin was still missing most of their gut diversity a year later. And athletes who took the same antibiotics eradicated 95 percent of their gut diversity. She also studied amateur and competitive cyclists, whose test results showed that they had higher levels of prevotella. This suggests a relationship between training intensity and gut health. Another group of researchers discovered that Irish rugby players had double the gut diversity of the average person. Increasing aerobic fitness is great for gut health and can help overall wellbeing, even for power athletes. You just need to make sure you’re not consistently overreaching in your training.

// In your book, Peak, you explore a “food first” approach to gut health. Can you summarize this?

If an athlete gets tested and finds out they’re low in a certain kind of bacteria, it’s tempting for them to just start taking a probiotic to address this or to start eating one type of food. But this reductionist approach doesn’t tend to work well in the long run. It’s better to eat a lot of different fibrous foods, and a wide variety of fruit and vegetables. Fermented foods like Greek yogurt can also be beneficial. For those who don’t do dairy, even soy yogurt is a good choice. There’s a lot of noise on social media about soy and endocrine disruption, but a recent meta-analysis showed that normal dietary levels don’t impact hormone balance. Another food group that can increase gut diversity is resistant starches – just cook and cool oats, rice, and lentils before eating them. The work of researchers like Miguel Mateas show that if we want a healthy gut, a diverse diet is essential. 

It can be helpful to make a chart of 50 or more foods for players to try and check off the list. Each new food will signal their gut in a different way. Hydration is also part of the picture. You’ve got to get enough fluids. If an athlete is getting sick a lot or underperforming, we tend to obsess about their training, but it could be as simple as changing up what they’re eating. When they’re struggling, gut health is one lever we can pull to create a more resilient athlete and a healthier human being.

Check back soon for part 2