Authored by George Citroner via The Epoch Times (emphasis ours),

Coffee drinkers consistently harbor up to eight times more of a specific gut bacterium than nondrinkers, according to recent research.

The international study, which tracked the drinking habits of nearly 77,200 people across 25 countries, found that coffee consumption leaves a distinct microbial signature. Researchers can identify coffee drinkers with 95 percent accuracy by examining their gut bacteria alone.

How Your Brew Affects Gut Microbiome

A 2021 study established that coffee had the strongest correlation with microbiome composition among over 150 studied foods, notably affecting levels of Lawsonibacter asaccharolyticus in approximately 1,000 people.

The latest study by researchers from the CIBIO Department at the University of Trento in Italy and Harvard University, published in Nature Microbiology in November, aimed to deepen understanding of how coffee affects gut health.

To achieve this, researchers analyzed diet and medical data from nearly 23,000 people in the United States and UK, along with publicly available data from almost 54,200 people worldwide. They compared stool samples from coffee drinkers and nondrinkers to identify differences in their gut bacteria composition.

The study found a strong association between coffee consumption and the levels of L. ​asaccharolyticus, with coffee drinkers exhibiting about five to eight times higher levels of this bacterium than nondrinkers.​

This trend was globally consistent, revealing that in coffee-consuming regions such as Luxembourg, Denmark, and Sweden, L. asaccharolyticus is prevalent. Contrastingly, it is nearly absent in countries like China, Argentina, and India.

The findings offer insights into how individual foods interact with our microbiomes and their potential effects on health.

The research team demonstrated that individual microbiome profiles could predict coffee consumption with 95 percent accuracy. A lab experiment confirmed that its growth rate increases when L. asaccharolyticus is grown in an in vitro environment with coffee. Further observations indicated that people who drank a lot of coffee exhibited a greater abundance of this bacterium.

Despite these findings, the role of L. asaccharolyticus in human health remains uncertain. Its presence in the gut microbiome correlates with increased levels of hippurate, a marker of metabolic and gut health produced by gut microbes that metabolize plant compounds called polyphenols found in coffee.

“We do not have conclusive evidence regarding Lawsonibacter asaccharolyticus as a beneficial or detrimental bacterium,” Nicola Segata, professor of genetics and head of the Computational Metagenomics Laboratory at CIBIO, told The Epoch Times. He noted that the research team is conducting specific additional experiments to better address this question.

Future of Microbiome Testing

The research team aims to expand their inquiry into the effects of other foods on gut microbiota, although they recognize the challenges of accurately quantifying food intake.

These findings suggest a potential for using individual foods to increase the abundance or prevalence of specific gut microbes that are supposed to have beneficial effects, according to Segata. “To achieve this, we need to expand this work to many other foods and other microbes, and this is exactly what we are also working on right now,” he said.

The researchers envision a future where microbiome testing can enable personalized dietary recommendations tailored to the presence of specific bacteria associated with certain foods. This approach has the potential to help people optimize their diets for better health by considering the intricate relationships between our food intake and microbiome composition.

“When looking at a food like coffee that is easy to collect information for, and that it is consumed either very frequently or never, then these links are popping out as very strong and very clear,” Segata said.