Gut microbiota changes showed no consistent link to better exercise performance
A review of controlled interventions in healthy, active adults found mostly small, variable bacterial changes and too little evidence for firm performance conclusions.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Changing gut microbiota did not consistently accompany better exercise performance in the reviewed studies. Most changes in stool bacteria were small or variable, and direct links between those changes and performance were rarely examined. This leaves the effectiveness of microbiota-targeted approaches uncertain, rather than showing that every such intervention has no effect.
The review identified common risks of bias and differences in interventions, outcome measures and microbiota testing. Only a subset examined the microbiota–performance relationship, which limits conclusions about whether bacterial changes explain any performance changes.
What was measured
Researchers considered stool bacterial composition and diversity alongside exercise outcomes such as time trials, time to exhaustion and maximal strength. They also looked for short-chain fatty acids, although these were measured infrequently in the included studies.
Why the link remains unclear
Only 7 studies examined relationships between changes in bacterial profiles and performance, with limited or inconclusive results. A change in a stool measurement cannot itself be read as evidence of improved sporting performance.
The original publication
Gut Microbiota and Exercise: A Systematic Review of Interventions and Evidence Limitations.
Gaskell SK, Martinez I, Costa RJS
Int J Sports Med · 2026
- PubMed ID
- 40967590
- Record checked
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