Can a Prebiotic Really Help Your Gut During Exercise? Science Says Yes
It’s no secret that endurance athletes often face gut issues during intense training—especially in the heat. Now, a new clinical trial led by Monash University has put True Gut Health to the test to see whether it can offer protection during these physically demanding conditions. The results are promising - keep reading as our Head of Product Innovation, Sherry Sui PhD, breaks the study down for us.
Why Was the Study Done?
Many endurance athletes experience gastrointestinal distress during prolonged, high-intensity exercise—particularly in hot conditions. This is known as Exercise-Induced Gastrointestinal Syndrome (EIGS). When it occurs, blood flow is redirected away from the gut to fuel working muscles, which can damage the gut lining and allow harmful bacteria to enter the bloodstream. This increases inflammation and can lead to symptoms like nausea, vomiting, stomach cramps, and diarrhea—ultimately impairing performance and recovery.
The goal of this study was to investigate whether taking True Gut Health prebiotic supplement over 8 weeks could help reduce gut damage and support overall gut health during heat-stressed endurance exercise.
How Was the Study Conducted?
Researchers conducted a double-blind, randomised placebo-controlled trial involving sixteen endurance-trained athletes aged in their 20s to 40s. Participants completed two 3-hour treadmill runs in a climate chamber set to 30°C—once at the beginning and again after 8 weeks of daily supplementation.
Half the group received True Gut Health prebiotics (16g/day), while the other half received a placebo. Researchers measured multiple markers of gut health, including:
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Gut lining damage
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Bacterial toxin levels in the blood
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Inflammation
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Digestive function
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Gut microbiome diversity (from faecal samples)
What Did They Find?
The results showed several positive outcomes for those who took True Gut Health:
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Stronger gut barrier: Prebiotic users experienced less gut damage during exercise, while those on the placebo showed increased gut injury after 8 weeks.
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Reduced harmful bacteria leakage: Blood levels of bacterial toxins (sCD14) were lower in the prebiotic group, indicating better gut barrier protection.
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Improved gut microbiome: Prebiotic users saw an increase in beneficial bacteria, particularly from the Ruminococcaceae family. The placebo group showed minimal change.
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No increase in gut discomfort: Importantly, there were no additional symptoms like bloating, cramping, or discomfort during exercise.
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No effect on digestion speed: Prebiotics didn’t alter how quickly food moved through the gut.
What Does This Mean for You?
Taking True Gut Health for 8 weeks has been clinically shown to reduce gut lining damage and inflammation during prolonged, intense exercise in the heat.
It also enhanced gut microbiome diversity—supporting a healthier and more resilient gut. And importantly for athletes, it didn’t lead to unwanted digestive symptoms, making it a safe and promising option for endurance performance and recovery.
While more research is needed in larger groups, this study is a strong step forward in understanding how prebiotics can support athletes when they need it most.
Publication reference:
Rauch et al 2025, The Effects of Prebiotic Supplementation on Markers of Exercise-Induced Gastrointestinal Syndrome in Response to Exertional Heat Stress. International Journal of Sport Nutrition and Exercise Metabolism. DOI: https://doi.org/10.1123/ijsnem.2024-0127.
Disclaimer
This research was funded by True Protein Pty Ltd. through the Australian Government’s Innovation Connections grant scheme. True Protein had no involvement in the study design, data collection, analysis, or interpretation. True Protein provided the prebiotic supplement used in the study.
