A Stable Gut Helps Elite Athletes Perform Better

Summary: Short-term high-protein diets have been associated with gut microbial instability that appears to hamper performance in elite athletes.

Source: Anglia Ruskin University

New research has shown that microbial instability in the gut can hamper performance in elite endurance athletes and that short-term high-protein diets are associated with this type of imbalance.

Researchers across the UK analyzed the performance and gut health of a group of well-matched, highly trained endurance runners to explore the impact of high-protein and high-carb diets.

The study found that in those who ate a high-protein diet, it led to a disruption in the stability of the gut microbiome. This also came with a 23.3% reduction in time trial performance.

The analysis revealed significantly reduced diversity and altered composition of the gut phageome, as well as higher levels of certain virus types and bacterial compartments. Participants with a more stable gut microbiome performed better in time trials.

Gut imbalance affects different people in different ways, but can manifest itself in acute symptoms such as cramping or nausea. Since there is an interaction between the gut and the brain, the authors suggest this may be important.

Those on a high-carb diet had a 6.5% improved time trial performance.

Dr Justin Roberts, Associate Professor of Health and Exercise Nutrition at Anglia Ruskin University (ARU) and co-author of the study, said: “These results suggest that athletic performance may be linked to gut microbial stability, where athletes who had more stable microbe communities consistently performed better in each dietary intervention compared to those with more turbulent gut microbiota.

Those on a high-carb diet had a 6.5% improved time trial performance. Image is in public domain

“Although we cannot be certain that the high amount of protein in the body is entirely responsible for the significant drop in time trial performance, it was found that there were definitely changes in the gut microbiome following a short-term high-protein diet that seemed to be associated with performance.

“These results suggest that consuming a high-protein diet may negatively impact the gut via an altered microbial pattern, while a high carbohydrate intake, e.g. containing a variety of grains and vegetables, was associated with greater intestinal microbial stability.

“The diets were well controlled and carefully balanced and so we believe it is unlikely that the protein itself caused a decline in performance. Instead, we believe it is possible that changes in the gut microbiome have an impact on intestinal permeability or nutrient absorption, or the messages between the gut and the brain, affecting perceived exertion and therefore performance.

The study was published in the Journal of the American Society for Microbiology mSystems and was carried out by researchers from Northumbria University, Anglia Ruskin University (ARU), University of Reading, University of Newcastle, University of Kent, University of Hertfordshire and North West University in South Africa.

About this microbiome and food research news

Author: Jamie Forsyth
Source: Anglia Ruskin University
Contact: Jamie Forsyth – Anglia Ruskin University
Image: Image is in public domain

Original research: Free access.
“Gut microbial stability is associated with greater endurance performance in athletes who undertake dietary periodization” by Justin Roberts et al. mSystems


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Gut microbial stability is associated with greater endurance performance in athletes who undertake dietary periodization

High protein or high carbohydrate dietary manipulations are frequently used during elite athletic training, aimed at enhancing athletic performance. Such interventions are likely to have an impact on the microbial content of the gut.

This study explored the impact of acute high protein or high carbohydrate diets on measured endurance performance and associated changes in the gut microbial community.

In a cohort of well-matched, highly trained endurance runners, we measured performance outcomes, as well as gut bacterial, viral (FVP), and bacteriophage (IV) communities in a randomized, double-blind, repeated-measures controlled trial. (RCT) to explore the impact of a dietary intervention with high protein or carbohydrate content.

High dietary carbs improved time trial performance by +6.5% (P < 0.03) and was associated with the expansion of Ruminococcus and Collinselle bacterial species.

Conversely, a high-protein diet reduced performance by -23.3% (P = 0.001). This impact was accompanied by a significantly reduced diversity (IV: P= 0.04) and altered composition (IV and FVP: P= 0.02) of gut phageome as well as enrichment of both free and inducible Sk1virusand Leuconostocbacterial populations.

The best performance when modifying diet was seen in participants with less significant changes in community composition. Gut microbial stability during acute dietary periodization was associated with better athletic performance in this highly trained and well-matched cohort.

Athletes and those who support them should be aware of the potential consequences of dietary manipulation on gut flora and implications for performance, and periodize appropriately.

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