Beer belly: How imbibing a brewsky can boost gut microbial diversity


Dear Doctors: I enjoy staying current on research into the gut microbiome. But I have to say, the new information I’ve been reading -- that drinking beer is good for your gut -- sounds a lot like wishful thinking. Where did this idea come from? Will having a beer really help your gut microbiome?

Dear Reader: We join you in being fascinated by how the trillions of microorganisms that live within and upon our bodies affect our physical and mental health. Research into the gut microbiome actually dates back to the mid-1800s. But it’s only in the last few decades, thanks to significant breakthroughs in DNA and genomic sequencing, that scientists have been able to study the gut microbiome at the molecular level.

An important early discovery was the link between a robust and diverse collection of microorganisms in the gut and a decreased risk of developing a wide range of chronic and metabolic diseases. This led researchers to study how various environmental and behavioral factors, including the food and beverages we eat and drink, affect the diversity of bacteria living in the gut. And that brings us to the beer news that you’re asking about.

The study, which recently appeared in the Journal of Agricultural and Food Chemistry, found that drinking beer can help someone’s gut microbiome become more diverse. The researchers learned this by analyzing the gut microbiomes of 19 men, who were asked to drink one 11-ounce beer each day for four weeks. The men were randomly divided into two groups. This was done so that researchers could collect data on the effects of both alcoholic and nonalcoholic beer.

Elizabeth Ko, MD and Eve Glazier, MD
Based on the blood and stool samples that were collected at both the start and the conclusion of the study, researchers found that both types of beer increased the diversity of the microbial populations in the participants’ guts. There was also an increase in the activity of an enzyme, known as alkaline phosphatase, that helps defend the gut from bad bacteria. Activity by this enzyme also indicates that the intestinal barrier, which allows for optimal immune function and nutrient intake, is working well.

Since both the alcoholic and nonalcoholic beers led to an increase in microbial diversity, researchers discounted alcohol as a contributing factor. Instead, they attributed the positive response to organic compounds known as polyphenols. As we discussed in a recent column, this is a category of micronutrients that occurs naturally in plants, and it is also found in wine and beer. Polyphenols have been shown to possess antioxidant and anti-inflammatory properties and have been linked to a range of beneficial health effects. Because beer is made via the process of fermentation, it contains microorganisms. These can also contribute to the diversity of a beer drinker’s gut microbiome.

This research suggests that drinking beer can boost microbial diversity, which is an important factor in gut health. But it’s just as important to remember that alcohol carries its own set of risks. If someone is genuinely interested in improving their gut health with beer, then this study shows that the nonalcoholic variety will do the job.

(Send your questions to [email protected], 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.)