A bubbly beer or glass of wine complements your meal and is soothing. But what effect does alcohol have on the trillions of microorganisms that live in your gut?
As with much of microbiome science, “there’s a lot we don’t know,” says Dr. Lorenzo Reggio, a physician-scientist who studies alcohol use and addiction at the National Institutes of Health.
That being said, it’s clear that happy microbes are essential for proper digestion, immune function, and gut health. And scientists are beginning to study how drinking affects the gut, and are learning that drinking too much can have unfortunate consequences.
How does heavy drinking affect the microbiome?
Dr. Cynthia Hsu, a gastroenterologist at the University of California, San Diego, says most of the available research on alcohol and the microbiome focuses on people who drink heavily on a regular basis.
a a handful the studyFor example, we know that there are people who: alcohol use disorder People who are unable to control or stop their problem drinking often have an imbalance of “good” and “bad” bacteria in their gut. This is called dysbiosis, and is generally associated with greater inflammation and disease compared to a healthier microbiome, Dr. Hsu said.
Reggio says that heavy drinkers with dysbiosis may have “leaky”, or more permeable, intestinal linings. A healthy intestinal lining acts as a barrier between the inside of the intestine, which is filled with microorganisms, food, and potentially harmful toxins, and the rest of the body, he said.
When the intestinal lining is destroyed, bacteria and toxins can escape into the bloodstream and into the liver, causing inflammation and damage to the liver, Dr. Hsu added.
Preliminary investigation Dr. Jasmohan Bajaj, a hepatologist at Virginia Commonwealth University and the Richmond VA Medical Center, said that even suggests an unhealthy gut may contribute to alcohol cravings.
in 2023 surveyFor example, researchers looked at the microbiomes of 71 people between the ages of 18 and 25 who did not have alcohol use disorder. Those who reported a high frequency of binge drinking (defined as (4 or more drinks for women and 5 or more drinks for men within about 2 hours), microbiome changes were seen that correlated with increased alcohol craving. The research also Previous research The results showed that binge drinking was associated with increases in blood markers of inflammation.
However, none of these studies have proven that alcohol causes dysbiosis in humans. While the association is more obvious in animal studies, human studies make it harder for researchers to control for factors such as diet and other health conditions.
What happens to people who drink less?
federal guidelines Define moderate drinking Men are limited to two drinks per day and women are limited to one drink per day. Jennifer Barb, a clinical bioinformatics scientist at the National Institutes of Health, said there is little research into how this amount of alcohol consumption affects the gut microbiome.
scientist have found Compared to people who don’t drink at all, low-to-moderate drinkers have a more diverse gut microbiome, a characteristic commonly associated with a healthy gut. This could be due to other dietary or lifestyle factors, or it could be something in alcoholic drinks that benefits the microbiome, but it’s likely not the ethanol, Barb said. said.
in 2020 survey For example, a study of 916 British women who drank two or fewer drinks a day found that the diversity of gut microbes in women who drank red wine (or, to a lesser extent, white wine) It turned out to be better than women who did not drink. No such association with beer or liquor was found. The researchers hypothesized that polyphenols found in grape skins, which are found in high concentrations in red wine, might explain the results.
But you don’t need alcohol to find out PolyphenolJohn Cryan, a neuroscientist who studies the microbiome at University College Cork in Ireland, says the microbiome is also found in grapes, most other fruits and vegetables, many herbs, coffee and tea. He said there was.
In general, consuming a variety of plant-based and fermented foods such as yogurt, kombucha, and kimchi can also improve microbiome diversity.
Can cutting back on alcohol improve your gut health?
researcher have saw Dr. Barb said that when looking at the microbiomes of people treated for alcohol use disorder, they found that within two to three weeks of stopping drinking, the gut microbes began to show signs of recovery and the gut lining healed. He said he understood. Less “leakage”“However, people who receive treatment for alcohol use disorder typically also eat healthier and sleep better, which can also improve their gut health, she added.
Dr. Reggio said it’s not clear how or whether quitting or reducing alcohol will affect the microbiome of moderate drinkers.but we know that Alcohol may cause He added that it can cause acid reflux, inflammation of the stomach lining, gastrointestinal bleeding, and increase the risk of several types of cancer, including those of the esophagus, colon, and rectum.
So there’s “no question” that cutting back on alcohol consumption is a worthwhile endeavor for your health, Dr. Reggio said.