Well, sports fans, we have arrived at Volume 5, and very likely the last of the Performance Biology series. I started this series because I had a question. Professional sports organizations are highly adept at measuring athletes. They monitor sleep, heart rate, training load, recovery, hydration, nutrition, movement, performance, and probably quite a bit more that I don’t know about. It seems they can measure nearly everything except how annoyed an athlete is that someone keeps measuring him.
Over the course of these articles, I’ve followed the relationship between the gut and athletic performance through travel biology, gut training, exercise-induced gastrointestinal problems, immune resilience, postbiotics and, somewhat astonishingly, dead bacteria.
I’ve been very careful not to say that supporting the microbiome will make an athlete faster, stronger, healthier or more available to play, mostly because we don’t have the data to support that conclusion. But I am growing weary of saying, “I don’t know.”
What if we added gut health to what teams are already measuring?
What If We Added the Gut to the Data?
Professional teams already collect an extraordinary amount of information about their athletes. What would be the downside to adding a few gut-related measures to the mix?
Researchers studying probiotics in athletes have already measured things like gastrointestinal symptoms, respiratory illness symptoms and training information. The science is far from settled, but the idea of tracking these outcomes is certainly not new. So how difficult would it be to take the next step? From the bleachers out here, it doesn’t seem like a ridiculous addition.
What Would We Actually Do?
I’m not suggesting we recruit 500 professional athletes, hire twelve researchers and spend three years trying to publish a clinical trial. I would start smaller.
Take a group of athletes and establish a baseline. For several weeks, track what the team is already tracking, but add a handful of simple questions about the gut. I would include questions about digestive discomfort, bloating, reflux, bowel regularity, fueling and food tolerance. I would also ask about fatigue, illness symptoms, missed or modified training, and maybe even how the athlete responds to travel. Nothing particularly exotic or ridiculously clinical.
After establishing several weeks of baseline data, I would introduce one consistent gut-support intervention for, say, eight weeks. In my case, obviously, I would be interested in testing Original Biome. Ahem! And don’t come at me for a shameless plug. My game, my rules.
Then we measure what happens.
What Are We Looking For?
This is where I think the experiment becomes particularly interesting for gut-health fanatics like me. The question would not be: Did Original Biome make these athletes better athletes? Not only is that question too big, but in my opinion it completely ignores the foundation. Plus, we don’t want to change the measurements because we want a particular answer.
So instead we keep collecting the same information and asking the same questions:
- Did digestive discomfort change?
- Did bloating change?
- Was fueling easier to tolerate?
- Did bowel regularity change?
- Did athletes feel differently after travel?
- Were there differences in fatigue, illness symptoms, missed practices or modified training?
- Did anything change in the recovery information the team was already collecting?
- Did something happen that we weren’t looking for?
If I’ve learned anything from writing this series, it is that biological systems do not operate in neat little boxes. Sleep affects recovery. Travel affects sleep and digestion. Food isn’t particularly useful if an athlete can’t comfortably tolerate it. The gut and immune system communicate. Illness affects availability.
I’ve addressed each of these in earlier articles. We have seen together that one thing bumps into another. So rather than asking whether “gut health improves performance,” perhaps we should ask something more useful: What changes when we support the gut and watch the rest of the athlete?
Maybe Nothing Happens
Seeing the result would be my favorite part of the experiment.
Maybe nothing happens. Maybe eight weeks later, the numbers look exactly the same.I own the company that makes Original Biome, so obviously that isn’t the result I would be hoping for. But it would still be a result.
Maybe digestion improves but recovery doesn’t.
Maybe certain athletes notice a difference and others don’t.
Maybe travel days look different.
Maybe GI symptoms change.
Maybe nothing changes until week six.
Maybe something improves that we hadn’t even thought to measure.
Or maybe absolutely nothing happens.
Isn’t That Why We Measure?
Existing research gives us good reason to remain curious without pretending we already know the answer.
A meta-analysis of 14 studies involving athletes found that probiotic supplementation did not significantly reduce the number of illness days or respiratory illness episodes. But when athletes taking probiotics did get sick, their respiratory symptoms tended to be less severe.
Other research we’ve looked at throughout this series has raised questions about the microbiome and fueling tolerance, travel, immune function, fatigue and recovery.
None of that proves that a gut intervention will improve athlete availability. What it does do is give us a reason not only to ask the question, but to test the idea.
This Doesn’t Have to Be Complicated
Probably the biggest thing I have learned during my accidental education in sports science and professional athlete performance is that adding a measure for gut health doesn’t have to be remotely complicated. I started out assuming that professional sports organizations had already investigated every conceivable biological variable.
It hasn’t. Nobody has. The human body is far too complicated.
But professional sports may offer an unusually interesting place to investigate some of these questions precisely because so much information is already being collected. We don’t need another wearable. We don’t necessarily need another dashboard. Maybe we just need to put another piece of information beside the data we already have. How is the athlete’s gut doing?
And then watch.
Five Articles Later
I started the Performance Biology series wondering whether professional sports had become better at measuring recovery than influencing it. Since then, I have followed the gut through airplanes, fueling, illness, immune function and some extremely surprising research involving bacteria that weren’t even alive anymore.
All along, I’ve reiterated that I didn’t know where this was going. Five articles later, I still don’t have the answer I was looking for. But I have a better question. What happens when we add the gut to what we’re already measuring?
Again, maybe nothing. But what if it was something? What if we discovered a change we hadn’t expected or a connection we hadn’t thought to look for? What if the something turned out to be something pretty incredible.
There’s only one way to find out.
So, sports fans, who wants to measure it with us?
References
Łagowska K, Bajerska J. Probiotic Supplementation and Respiratory Infection and Immune Function in Athletes: Systematic Review and Meta-Analysis of Randomized Controlled Trials. Journal of Athletic Training. 2021;56(11):1213–1223. doi:10.4085/592-20.
Di Dio M, Calella P, Cerullo G, et al. Effects of Probiotics Supplementation on Risk and Severity of Infections in Athletes: A Systematic Review. International Journal of Environmental Research and Public Health. 2022;19(18):11534. doi:10.3390/ijerph191811534.
Costa RJS, Gaskell SK, Henningsen K, et al. Sports Dietitians Australia and Ultra Sports Science Foundation Joint Position Statement: A Practitioner Guide to the Prevention and Management of Exercise-Associated Gastrointestinal Perturbations and Symptoms. Sports Medicine. 2025;55:1097–1134. doi:10.1007/s40279-025-02186-6.
Mohr AE, et al. It’s Dead! Can Postbiotics Really Help Performance and Recovery? A Systematic Review. Nutrients. 2024;16(5):720.
Komano Y, Shimada K, Naito H, et al. Efficacy of heat-killed Lactococcus lactis JCM 5805 on immunity and fatigue during consecutive high intensity exercise in male athletes: a randomized, placebo-controlled, double-blinded trial. Journal of the International Society of Sports Nutrition. 2018;15:39. doi:10.1186/s12970-018-0244-9.
Disclaimer
The information in this article is for educational purposes only and is not medical advice. Research involving probiotics, postbiotics, the microbiome, immune function and athletic performance is ongoing. Findings discussed here should not be interpreted to mean that Original Biome or any supplement can prevent illness, improve athletic performance or produce any specific outcome. Individual results may vary, and athletes should consult their healthcare, sports medicine and nutrition professionals regarding individual health and supplementation.
