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Gut Issues and Probiotics

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Gastrointestinal (GI) issues affect many endurance athletes and are a primary reason for performance impairment in ultrarunning. Most athletes encounter some form of stomach related issues during longer races and avoiding or mitigating these would be a real positive. Hour 7 physiologist, Dr Jamie Pugh, is an expert in this area and has been involved in several studies investigating the gut. His work includes this study on the potential role of probiotic supplementation.

In this paper, in which Jamie was the lead researcher, 4 weeks of probiotic supplementation reduced the incidence and the severity of GI issues in marathon runners. This reduction in GI issues may help athletes to maintain higher performance levels, particularly in the latter stages of a race. The pathways in which the probiotics elicit these positive effects is yet to be clarified but probiotic supplementation leading up to a key race appears to be a simple way to reduce the chances of a race being spoiled by an uncooperative gut.

Choosing the right probiotic supplement appears to be key as the types and amounts of bacteria can be different from product to product – and this may affect how effective it is. This paper also discusses different factors that can cause GI issues, some of them psychological. As with many aspects of endurance performance, there are a plethora of reasons why an athlete may encounter physiological issues and not all of them are as straight forward as taking a supplement for several weeks.

It should also be noted that even in the probiotic group, some athletes still experienced symptoms. So, they are by no means a cure all. If you are experiencing symptoms consistently during training, races, or just in your day-to-day activities, it is also important to seek further advice to rule out any clinical issues that may be underlying, and to also help ensure other potential causes of GI symptoms are considered (stress, diet, environmental, etc.)


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