Research shows positive results in gastric issues reduction
Studies looking at probiotics and athletic performance are scarce and show contradictory results. However, research on the impact of probiotics on the gastric tract is more promising. A study published in the Journal of the International Society of Sports Nutrition in 2022 is a good example.
The authors recruited 27 elite cyclists and assigned half of them to take a daily multi-strain probiotic supplement for 90 days, while the other half received a placebo. Each participant had to go through a GI symptoms questionnaire, oxygen consumption test and time-to-fatigue at 85 % of max power at the beginning of the study and then at the end. The results revealed that cyclists in the probiotic group experienced less nausea, belching, vomiting, and other GI symptoms during training. There were no changes in oxygen usage or fatigue, which means their performance stayed the same.
While this is definitely an encouraging result and you may be thinking that every cyclist should start taking probiotics, it’s important to consider the limitations of researching probiotics and the practicalities of taking them.
Studies on probiotics are difficult to interpret
Studies on probiotics often suffer from methodological issues such as not testing whether the supplements used actually contain living bacteria, not reporting storing conditions of the probiotics, not tracking other dietary practices, and having a very small sample size. These and other shortcomings are described in a recent 2023 systematic review which says that interpretation of these studies is challenging even for health care practitioners.
And if that wasn’t enough, you also have to take into account that probiotic supplements are poorly regulated. There is often no independent institution testing the supplements to make sure they contain exactly what they claim. So, when you start taking a supplement you may not be getting what you think you are.
Start with probiotic foods
Even if you see positive results in a study here and there, it’s advisable to proceed with caution instead of assuming you will gain the same benefit as the participants of that study. We know that it’s important to build your supplementation regimen on top of a balanced diet with a wide range of whole foods. That should be your priority. A low-risk approach is also to start introducing probiotic-rich fermented foods such as yogurt, sauerkraut, pickles, tempeh, miso, or kimchi. Introducing a probiotic supplement is certainly not a guarantee of GI improvements related to cycling based on the latest available research.