Large-scale DNA analysis enabled researchers to examine what factors affect the diversity of the microbiome, the intestinal bacterial community unique to each individual. Coffee and wine can increase the diversity of gut bacteria, while whole milk or a high-calorie diet can decrease it.
“In total we found 60 dietary factors that influence the diversity. What these mean exactly is still hard to say,” Alexandra Zhernakova, a researcher at the University of Groningen in the Netherlands and the first author of the study, said in a statement, according to EurekAlert.“But there is a good correlation between diversity and health: greater diversity is better,” she added.
Researchers collected questionnaires on the diet, medicine prescriptions and health of over 1,100 people, and analyzed their gut DNA from frozen stools. Unlike other studies, the Dutch research focused on normal people, while previous studies had chosen to examine patients with specific illnesses.
“Normally researchers only investigate one particular region of DNA in which different groups of bacteria can be distinguished,” Professor of Human Genetics Dr Cisca Wijmenga of the University of Groningen said. “We have mapped all the bacterial DNA to gain much more detailed information about bacteria types.”
Researchers managed to identify as many as 126 factors related to the changes in the makeup of an individual’s microbial community, according to the study published in the journal Science.
These include “60 dietary factors,” 12 associated with diseases, 19 linked with drugs, and four tied to smoking. “These factors collectively explain 18.7 percent of the variation seen in the interindividual distance of microbial composition,” researchers wrote, adding that these results are “an important step toward a better understanding of environment-diet-microbe-host interactions.”
After analyzing the stool samples of over a thousand Dutch participants in the Lifelines-DEEP study, the scientists found that people who regularly consume yogurt, buttermilk, fruits and vegetables have a greater diversity of gut bacteria. Drinking coffee, tea and wine also proved to be good for one’s gut.
“To our knowledge, this is the first study to systematically assess such a broad range of host and environmental factors in relation to gut microbiome and [on] such a large scale,” Jingyuan Fu, a systems geneticist at the University of Groningen who worked with Zhernakova, told the Los Angeles Times.