New research reveals high-protein diet may worsen gut stability in athletes, while a high-carb diet leads to improvements.
What helps athletes keep their peak performance? According to researchers from the United Kingdom, it’s all about a stable gut. Many athletes opt for a high-protein diet to fuel muscle growth, while runners often load up on carbohydrates. It turns out gut stability can hinge on the diet one chooses.
For their study, researchers examined the performance and gut health of a group of endurance runners. They wanted to investigate the impact of both high-protein and high-carbohydrate diets.
Researchers found endurance runners with a high-protein diet had increased gut microbiome instability. This type of imbalance led to a 23.3 percent reduction in time trial performance. However, runners who underwent a high-carbohydrate diet had an improved time trial performance of 6.5 percent.
The study’s authors report there was decreased diversity and altered composition of the gut phageome. There were also higher levels of virals and bacterial compartments. Runners who had a more stable gut microbiome performed better during time trials.
“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,” explains study co-author Dr. Justin Roberts, associate professor in health and exercise nutrition at Anglia Ruskin University, in a media release.
Gut imbalance can present itself in acute symptoms such as cramps or nausea. Researchers say this could be important since there is cross-talk between the brain and gut.
Dr. Roberts says, even though a high-protein diet may not totally be at fault for poor time-trial performances, there were changes to the gut microbiome following a short-term high-protein diet that was 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,” explains Dr. Roberts.
“The diets were well controlled and carefully balanced and so we think it is unlikely that the protein itself caused a drop in performance,” he continues. “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.”
The study is published in the American Society of Microbiology’s journal mSystems.