Sipping on a cup of joe is an easy way to infuse some much-need pleasure into a hectic morning or slow afternoon at work. But a growing body of research suggests that coffee might do your physical health a solid, too, even helping your gut cultivate some great bacteria.
A new study, which was published in Nature Microbiogy, found that a coffee habit is linked with a certain type of bacteria growth that’s believed to boost your gut health. However, the link is a little complicated. So, with that in mind, here’s what the study found, plus what doctors want you to know.
Meet the experts: Danbee Kim, MD, nutrition expert, weight loss surgeon, and assistant professor at Rutgers New Jersey Medical School; Nicola Segata, PhD, study co-author, professor, and principal investigator at the CIBIO Department of the University of Trento; Rudolph Bedford, MD, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, CA
What did the study find?
For the study, researchers analyzed fecal (i.e. poop) data from more than 20,000 people and tracked how much coffee they consumed on a daily basis.
The researchers found that people who regularly drank coffee also had a bacterium called Lawsonibacter asaccharolyticus in their gut.
“People who drink coffee, on average, have a six to eight times higher amount of this bacterium in the gut,” says Nicola Segata, PhD, study co-author, professor, and principal investigator at the CIBIO Department of the University of Trento.
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What is L. asaccharolyticus and why is it good for gut health?
We don't actually know a ton about L. asaccharolyticus. The bacterium was first identified in research in 2018. It produces butyrate, a sign of gut fermentation that suggests good digestion and nutrient absorption, Segata explains.
"It’s probably producing short-chain fatty acids, which are supposed to be positive modulators of immunity,” Segata adds. Still, he says that “strong data” is needed to learn more about what this actually does for your gut health.
What he does know is that there’s a solid link between coffee consumption and the presence of L. asaccharolyticus. Segata and fellow researchers actually fed coffee to L. asaccharolyticus that was growing in petri dishes and found it made the bacteria grow faster. “It’s clear that the coffee was stimulating it,” Segata says.
This stimulation is possibly due to metabolites in the coffee. Plus, it's “probably not the caffeine, because decaf had a similar effect," Segata adds.
Can I get L. asaccharolyticus from other foods?
As of now, this bacterium is just linked to coffee.
However, aronia berries contain chlorogenic acid and polyphenols like coffee, so they may have a similar effect, says Danbee Kim, MD, nutrition expert, weight loss surgeon, and assistant professor at Rutgers New Jersey Medical School. “Other foods high in chlorogenic acid—such as blueberries, apples, and pears—might also support the growth of this gut bacteria, though more research is needed to confirm this,” she says.
How much coffee do I need to drink to reap the gut benefits?
Having a cup or two of coffee a day promotes the growth of L. asaccharolyticus, Segata says. But he points out that “heavy” coffee drinkers, who have three or more coffees a day, have up to 10 times more of the bacteria in their gut compared to people who don’t drink coffee.
Are there any negative impacts of coffee on gut health?
There are a few to keep in mind. The biggest potential drawback is that it could raise your risk of acid reflux, says Rudolph Bedford, MD, a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, CA.
“It also increases gastrointestinal mobility and can potentially cause diarrhea,” he says. But, overall, Bedford says that coffee is considered a relatively safe drink for people, provided they don’t overdo it on the caffeine.
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Korin Miller is a freelance writer specializing in general wellness, sexual health and relationships, and lifestyle trends, with work appearing in Men’s Health, Women’s Health, Self, Glamour, and more. She has a master’s degree from American University, lives by the beach, and hopes to own a teacup pig and taco truck one day.