Could the Therapeutic Effect of Physical Activity on Irritable Bowel Syndrome Be Mediated Through Changes to the Gut Microbiome? A Narrative and Hypothesis Generating Review

Abstract

Background: Irritable bowel syndrome (IBS) is one of the most prevalent gastrointestinal (GI) disorders worldwide. Defined as a disorder of gut-brain interaction, its pathophysiology is still not completely clear. Consequently, current treatments primarily target symptoms rather than addressing the cause of the condition. The gut microbiome is increasingly acknowledged as central to IBS pathophysiology and, thus, may have therapeutic potential. Several national treatment guidelines recommend increasing physical activity for IBS management. Aims: This review summarises the evidence about the relationship between physical activity, IBS symptoms, and the gut microbiome, investigating the hypothesis that physical activity's therapeutic effects on IBS may be explained via modulation of the gut microbiome. Results: This review revealed that routine exercise was associated with a 15%–66% reduction in symptom severity and up to 41% enhanced QoL in IBS participants, and modulates the gut microbiome in healthy controls. Discussion: This review generates the hypothesis that routine physical activity may favorably alter gut microbiome composition in IBS to improve IBS symptomology. While a plausible hypothesis, research needs to confirm whether gut microbiome modulation is involved in physical activity associated IBS symptom relief. Conclusion: Furthermore, the establishment of the most effective mode, duration, and intensity of physical activity for each sex and IBS-subtype is needed, with patient input during this process crucial to successfully translate science into practice.