The composition of our gut microbiome is known to influence many elements of the human body, and new lines of research are uncovering some fascinating insights around how this extends to athletic performance. The latest findings in this space suggest that more stable communities of gut bacteria can boost performance among endurance runners, and suggest that diet may play a pivotal role.
Previous research has demonstrated that exercise can directly influence the makeup of our gut bacteria, and more recently, studies have begun to show that the opposite may also be true. This includes findings that certain bacteria species are heightened in marathon runners after an event, and that increases in some of them can even improve our motivation to exercise.
Scientists at the UK’s Anglia Ruskin University have delved further into this relationship through a new study involving a cohort of high-level endurance runners. These participants were placed on either a high-protein diet or a high-carbohydrate diet, with the intention of studying the effects on the gut microbiome, and the potential repercussions for athletic performance.
The scientists found that those on a high-protein diet experienced a disturbance in the stability of the gut bacteria, with significant reductions in diversity of species and higher levels of bacterial compartments. Interestingly, the team found this brought on a 23.3% decrease in time trial performance. Conversely, the high-carb diet led to an improved time trial performance of 6.5 percent among that group.
“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,” said co-author Dr. Justin Roberts, Associate Professor in Health and Exercise Nutrition at Anglia Ruskin University.
According to the team, the findings indicate that rather than a high-protein diet directly inhibiting the performance of the endurance runners, it is doing so indirectly via shifts in the gut bacteria.
“The diets were well-controlled and carefully balanced and so we think it is unlikely that the protein itself caused a drop in performance,” said Roberts. “Instead we think it is possible that the changes to the gut microbiome could impact intestinal permeability or nutrient absorption, or the messages between the gut and the brain, affecting perceived effort and therefore performance.”
The research was published in the journal mSystems.