Your choice of chocolate and contraceptive affect your gut bugs

时间:2019-03-06 08:02:02166网络整理admin

Julian Winslow/Plainpicture By Jessica Hamzelou Milk, dark or white? Your chocolate preference influences the make-up of the microbial community in your gut. That’s according to the largest ever study of human microbiomes. Along with chocolate, it has identified 68 other factors that shape your gut bacteria, including how much sleep you get, whether you smoke or drink alcohol, and which medicines you take. “We compared all the microbiota we could get our hands on,” says Jeroen Raes at the University of Leuven (KUL) in Belgium, who led the study. His goal is to work out what a healthy microbiome should look like, and his team have sequenced the microbiomes of hundreds of Belgian volunteers. Each volunteer also filled out detailed surveys on their diet, lifestyle and habits, and had their blood tested. “We’ve turned these people inside out,” says Raes. A statistical analysis of the first 1100 people in their ongoing project pulled out 69 factors that seem to be linked to the types of bacteria in a person’s gut. Some of these were expected – such as the amount of fruit and fibre a person eats. But others were more of a surprise. While we already knew that antibiotics – which kill bacteria by definition – can dramatically alter the gut microbiome, the team found that antihistamines, hormonal contraceptives and anti-inflammatory drugs also appear to have an effect. “It goes to show that medication and the microbiota are closely linked,” says Raes. The type of chocolate a person preferred was also a factor. “I think it’s extremely funny that, of all things, chocolate comes up in this Belgian population,” says Raes. But the strongest association for types of bacteria was with the shape and consistency of a person’s bowel movements, which give an indication of how long it takes food to pass through our bodies. This is an important finding for gastroenterologists around the world, who are investigating whether the microbiome can be used to diagnose or treat diseases. These studies need to account for their volunteers’ bowel movements, says Raes. “Otherwise you won’t know if you’re measuring disease or constipation,” he says. We still don’t know how harmful changes to your gut bacteria can be. Some strains of bacteria have been linked to good health or to cancer, but a reliable picture of a healthy microbiome is yet to be nailed down. Overall, the 69 factors only had a small effect on gut bacteria, accounting for about 7 per cent of the variation between individuals. It’s possible that genetics plays a more important role in shaping your microbiota. The bacteria themselves might also play a role in shaping their own ecosystem, says Raes. But amidst this variation, the team also identified a “core microbiota” of bacterial types we all seem to carry. By comparing the Belgian microbiomes with those from 3000 samples from around the world, including Papua New Guinea, Peru and Tanzania, they identified roughly 700 genera of bacteria that were present in all populations, and 14 genera that were present in every person. Journal reference: Science, DOI: 10.1126/science.aad3503   More on these topics: