Just as there are a few major blood types that divide up the world, so too, a study has found, there are just three types of gut-microbe populations. The result could help to pinpoint the causes of obesity and inflammatory bowel disease, and to personalize medicine. “Canada, in March. Ehrlich, a senior researcher on the paper published in Nature today1, is director of the Microbial Genetics Research Unit at the National Institute for Agricultural Research in Jouy-en-Josas, France, and part of a European consortium aiming to unpick links between gut microbes and disease. The finding of just three types of gut-microbe population was an unexpected result that fell out of the team's early analysis. The types aren't related to age, gender, nationality or diet. “What causes it? We don't know,” says Ehrlich.
One possible explanation, which the team is testing, is that a person's gut-microbe make-up is determined by his or her blood type. Alternatively, it might be determined by metabolism: there are three major chemical pathways by which people get rid of excess hydrogen gas created during food fermentation in the colon, and the gut type might be linked to those. Or, perhaps the first microbes a baby is exposed to as his or her immune system is developing determines the type. A person's gut type might help to determine whether people can eat all they like and stay slim, whether they will experience more gut pain than others when sick and how well they can metabolize a certain drug.