Indulge Comfortably on St. Patrick's Day: Beer & Dark Chocolate Good for the Gut

If you plan on joining the estimated 33 million people worldwide planning to celebrate St. Patrick’s Day with an estimated 13 million pints of Guinness, then go ahead and take March 18 off from your healthy habits because you’ll have spent the previous night diversifying your gut microbiome— and that’s good for your immune system, after all! If you drank red wine and indulged in some luscious dark chocolate dessert after hours, well, so much the better. At least, as long as you don’t do it every day.

According to the results of one of the largest population-wide studies of gut microbiota currently in existence, the Flemish Gut Flora Project (FGFP), there are about 69 factors that affect gut bacteria directly, including alcohol consumption and chocolate preference. Why should you care about the microscopic organisms in your gut? Well, it turns out gut bacteria and their relative levels of diversity in your gut are linked to mental health, obesity, and cancer, and you can even pass susceptibility to some of these issues down to your children.

While the initial results of the FGFP were published nearly a year ago, the lead researcher on the project, Jeroen Raes, PhD, a professor at the University of Leuven (KU Leuven), made St. Patrick’s Day relevant headlines when he announced the “Belgian Chocolate Effect” on the gut, which he used to describe one bacterial group’s preference for dark chocolate. He then added, “We also found an association between gut flora composition and beer consumption.” Study results also indicated that coffee and wine, in moderation, could increase bacterial diversity as well, a good thing because in general, gut diversity is linked to better health.

The FGFP consisted of a study of the stool samples of more than 1,000 health Flemish individuals and international collaborations with other researchers collecting similar data around the world. Participants froze their fecal samples themselves, and the samples were delivered to researchers still frozen rather than shipped to the labs and possibly exposed to oxygen or thawing during transit. The result, said the Raes’ research team, “set a new standard for future research in this field.” The group was able to identify 14 bacterial species that are present in nearly every individual’s gut in the world, which Dr. Raes noted at the time was a crucial step in developing diagnostics and treatments based on the gut microbiome. “You need to understand what is normal before you can understand and treat disease,” he explained in a public statement. He went on to say that his team would be pursuing the collection of the roughly 40,000 human samples “required just to capture a complete picture of gut flora biodiversity.” He added, “We are only seeing the tip of the iceberg,” and noted that FGFP “only explained seven percent of gut flora variation.”

Of course, this is not to say that heavy drinking is the answer to your health issues, nor, unfortunately, is excessive consumption of decadent desserts. In fact, just about anything in the extreme can hurt your microscopic intestinal residents and decrease their diversity, which is bad for your overall health. So before you decide to make your one-time contribution to the $5.3 billion that people the world over are about to spend on St. Patrick’s Day on beer a regular habit, think carefully about how your stomach will feel about that not just the next morning, but the next time you’re trying to fend off anything from a bad mood, to an upset stomach, to skin cancer.