Dear Doctors: I had to laugh when I saw there’s another new study about coffee. This one says it’s good for your gut microbiome. I’m 41 years old and a lifelong coffee drinker, and those studies come out like clockwork. Sometimes it’s good news, sometimes it’s bad. I’d like to know more about this one.
Dear Reader: There is no question that coffee is an extremely popular subject of study. Research into its possible health effects, both bad and good, dates back decades -- and small wonder. In the United States, coffee is by far our favorite beverage. We drink more of it than tea, soda and juice combined. Thanks to the caffeine it contains, coffee is a stimulant. That means habitual use can lead to a mild form of physiological dependence. Skip your daily brew and, as many regular coffee drinkers can attest, a nasty headache can be on the horizon.
That said, coffee is fascinating. A product of fermentation, it contains hundreds of chemical compounds, many of them bioactive. It also provides small amounts of magnesium, B vitamins and potassium, and it contains scores of phytochemicals with anti-inflammatory and antioxidant properties. Previous research has linked regular coffee drinking to improved blood sugar control, improved liver health, a lower risk of colon cancer and a reduced risk of developing diabetes, fatty liver disease and depression. With each advance in research tools and tech, investigators discover something new about coffee. And that’s where the study you are asking about comes in.
Because the gut microbiome plays such an important role in health and well-being, a team of researchers in Europe chose to explore how coffee may affect it. They analyzed health and medical data gathered from 75,000 people from 25 nations. The information included details about each person’s coffee consumption. The researchers also compared genetic and microbial profiles of stool samples collected from coffee drinkers and those who did not drink coffee.
The researchers found that people who regularly consume coffee have robust communities of a specific bacterium. Known as Lawsonibacter asaccharolyticus, this is a gut-friendly microbe that produces a compound called butyrate. For fellow science nerds, butyrate is a short-chain fatty acid. It helps moderate inflammation, bolsters the health of the gut-brain axis and is believed to contribute to the health of the cells that line the colon. People with a regular coffee habit had levels of Lawsonibacter asaccharolyticus that were eight times higher than nondrinkers. This held true no matter where in the world the study participants lived.
Researchers are now interested in learning if the known health benefits of coffee may be linked to high levels of Lawsonibacter asaccharolyticus. More study is needed to know if this is the case. The other interesting aspect of this study is the light it sheds on the growing awareness of the influence of diet on the gut. Not only do the foods we eat either nourish or harm the gut microbiome, but specific microbes appear to respond to specific foods. Now there’s (and here comes a dad joke) food for thought.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
