The surprising health benefit of drinking 2 cups of coffee per day

A healthy gut community attends nearly every biological function. 

The average person has between 300 and 500 different species of bacteria in their digestive tract. Not all of these mean us well, but the ones that do contribute monumentally to cardiovascular health, brain health,  mood, healthy sleep and the prevention of autoimmune diseases and certain types of cancer. 

There are several ways to facilitate a diverse gut microbe and a new study from The Baylor College of Medicine in Houston has elevated caffeine as chief among these. 

Before extracting microbial DNA from participants and performing 16s rRNA sequencing analysis, the participants completed self-administered food frequency questionnaires to evaluate their daily intake of coffee. 

The researchers divided coffee intake into high coffee consumption — that is, coffee containing at least 82.9 milligrams (mg) caffeine per day — and low coffee consumption, (coffee containing less than 82.9 mg caffeine daily).

Followup trials revealed that the microbiomes of habitual coffee drinkers were significantly healthier than those who consumed little to no coffee.

For the sake of practical application, habitual consumption can be defined as two or more cups of coffee a day. 

Quantities in this range appeared to produce bacterial species that were more abundant and evenly distributed throughout the large intestine, richer in anti-inflammatory properties, and less likely to include bacteria species associated with metabolic abnormalities and obesity

More specifically, high caffeine consumers expressed high levels of the beneficial bacterial genera Faecalibacterium and Roseburia, but low levels of Erysipelatoclostridium — a “potentially harmful” bacterial genus.

These outcomes were consistent irrespective of the participants’ age or the quality of their diets independent of coffee consumption.

“The study was conducted in 34 adult men who had [a] normal colon in a single hospital. It is unknown whether these preliminary results can be applied to women or other populations,” the authors write. “We used the 16S rRNA gene sequencing that cannot tell which bacterial species are important. We cannot tease out whether polyphenol or other compounds in coffee may also partially explain the association.”

Tertiary benefits of regular coffee consumption include but are not limited to:  reducing unhealthy fat,  decreased inflammation,  prevention of cognitive decline later in life, artery health, and preventing calcium buildup and clogging.

“We still need to learn more about how the bacteria and the host [our bodies] interact to impact our health,” said lead study author Dr. Li Jiao, an associate professor of medicine-gastroenterology at Baylor College of Medicine in Houston. “It remains uncertain why coffee exerts such a positive influence on the gut microbiome. The beneficial roles of coffee consumption in metabolic diseases have previously been shown.  We set out to examine whether phytochemical ‘caffeine’ in coffee would account for this beneficial effect.”

The research did not discern between coffee preparation or which brands the participants used. Either of these might influence the data set among some populations. 

As previously stated, the study also focused on specific bacteria species. More research needs to be done to uncover the mechanisms behind caffeine’s relationship to gut health. 

The findings were recently presented at The American College of Gastroenterology annual meeting.

 CW Headley is a reporter for the Ladders and can be reached at