A large international team of medical researchers has found that people who drink coffee regularly have much more of one type of gut bacteria than people who do not. In their study, published in the journal Nature Microbiology, the group analyzed stool and blood samples from a large number of patients and also studied similar data in large medical databases, looking for impacts of coffee drinking on the gut biome.

To learn about the impact of coffee drinking on the gut biome, the researchers began by analyzing medical data for approximately 22,800 people living in the U.K. and the U.S. and for another 54,200 people in 211 cohorts. This allowed them to compare stool sample data from people who reported drinking coffee and those who did not, while exploring differences in the gut biome between the two groups.

The researchers found one major difference in the two groups—the population numbers of a bacteria called Lawsonibacter asaccharolyticus. Those people who drank coffee regularly had levels as high as eight times those who did not—and the difference held steady for people all around the globe.

The research team acknowledges that they do not know what impact higher levels of L. asaccharolyticus may have on people, but suggest it is likely associated with health benefits that have been attributed to coffee drinking. They suggest there are substantial impacts of a single food or beverage on the human gut biome.