Recent studies also suggest that coffee can boost gut health. One study, in particular, linked high coffee consumption to higher levels of anti-inflammatory gut bacteria and improved composition of the gut microbiome.

Coffee improves composition of the gut microbiome

Researchers led by Dr. Shawn Gurwara of the Baylor College of Medicine investigated whether caffeine is responsible for coffee's health benefits. They noted that past research showed coffee has a beneficial effect against metabolic diseases like Type 2 diabetes and cardiovascular disease. However, how exactly coffee yields this benefit remained somewhat of a mystery.

Gurwara and his team looked at the link between caffeine consumption and the composition and structure of the "colonic-gut microbiota." They recruited 34 healthy male participants and had them answer a food frequency questionnaire to evaluate their daily coffee intake. The researchers categorized coffee intake as either high consumption if the participants drank coffee with at least 82.9 milligrams of caffeine per day, or low consumption if it contains less than that amount of caffeine.

The team collected 97 samples from various segments of the participants' colons and extracted microbial DNA. After performing 16s rRNA sequencing analysis, the researchers found that high coffee consumers had higher levels of the anti-inflammatory bacteria Faecalibacterium and Roseburia and low levels of Erysipelatoclostridium – a potentially harmful genus of bacteria.