According to new study, microbial instability in the gut can impair the performance of elite endurance athletes, and short-term, high-protein diets are linked to this sort of imbalance.
Researchers from across the UK investigated the influence of high-protein and high-carbohydrate diets on the performance and intestinal health of a group of well-matched, highly trained endurance runners. The study discovered that those who followed a high-protein diet had a disruption in the stability of their gut microbiota. This was followed by a 23.3% decrease in time trial performance.
The gut phageome’s diversity and composition were shown to be drastically decreased, with increased amounts of particular types of virals and bacterial compartments. Participants with more stable gut microbiomes fared better throughout time trials.
Gut imbalance affects various people in different ways, but it can cause acute symptoms like cramping or nausea. The scientists speculate that because there is cross-talk between the stomach and the brain, this might be significant.
A high-carbohydrate diet resulted with a 6.5 percent improvement in time trial performance.
Dr Justin Roberts, Associate Professor in 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 with gut microbial stability, where athletes who had more stable microbial communities consistently performed best in each dietary intervention compared to those with a more turbulent gut microbiota.
“While we cannot be certain that the high amount of protein in the body was entirely responsible for the significant drop in time-trial performance, it was found that there were certainly changes to the gut microbiome following a short-term high-protein diet which appeared 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, for example containing a variety of grains and vegetables, was associated with greater gut microbial stability.
“The diets were well controlled and carefully balanced and so we think it is unlikely that the protein itself caused a drop in performance. Instead we think it is possible that the changes to the gut microbiome could impact intestinal permeability or nutrient absorbtion, or the messages between the gut and the brain, affecting perceived effort and therefore performance.”