Some studies suggest that the community of microorganisms that live in the gut are associated with athleticism.
A week before the 2015 Boston Marathon, Jonathan Scheiman, then a postdoctoral researcher in the lab of geneticist George Church at Harvard Medical School in Boston, Massachusetts, was racing around the city in a hire car collecting faeces. He gathered stool samples from runners planning to participate, as well as those from non-runners — mostly fellow postdocs. After the race, he revisited his donors to collect more samples. Four years later, his efforts were rewarded with a paper describing one of the first attempts to establish a causal link between the symbiotic community of microorganisms living in our guts and athletic performance1.
Although the gut microbiome has been implicated in numerous aspects of health and disease, links with athleticism are much less studied. Interest is growing, however, helped by advances over the past decade that enable researchers to reveal not just which microbes the gut harbours but also what they do. Such work suggests that the enormous diversity of organisms that make up a person’s gut microbiome — each as unique as a fingerprint — might converge on a smaller number of functions, which, in turn, could suggest candidate mechanisms. And although elite athletes and their coaches might hope to be the first to benefit, a deeper understanding of the link between the gut microbiome and physical fitness might instead benefit the health of the wider population.
A box of puzzles
Of the trillions of microorganisms that live on and inside us, most are found in the gastrointestinal tract. Some are pathogens, but many are beneficial, and the overall community is essential to human health. Disruption of the microbiome is directly linked to gastrointestinal conditions, such as inflammatory bowel disease, and has been implicated in diabetes, cancer, heart disease, obesity and even mental health disorders. The clearest indication of the microbes’ importance comes from laboratory mice conditioned to carry none at all. “They’ve got metabolic issues, immune issues, neurological issues — you name it,” says Aleksandar Kostic, a microbiologist at Harvard and a senior author on Scheiman’s study. “Introduce a normal mouse microbiome to them, and many of these phenotypes are rescued,” he adds.
Work to unpick the mind-boggling complexity of the gut microbiome has been greatly aided by technical advances over the past two decades, and more affordable genetic sequencing. To investigate a community, researchers must sequence the genetic code of hundreds of organisms simultaneously, drawn from a cast of millions. To identify the microbes present in a sample — usually faecal matter in the case [ … ]