A cold beer or a glass of wine improves food and calms the mind. But what does alcohol do to the trillions of microbes that live in the gut?
As with much of microbiome science, “there’s a lot we don’t know,” says Dr. Lorenzo Leggio, a physician scientist who studies alcohol use and addiction at the National Institutes of Health.
That said, it’s clear that happy microbes are essential for proper digestion, immune function, and gut health. And as scientists begin to investigate how drinking affects your gut, they’re learning that overdosing can have some unpleasant consequences.
How does excessive drinking affect your microbiology?
According to Dr. Cynthia Hsu, a gastroenterologist at the University of California, San Diego, most research on alcohol and microbiology has focused on people who drink regularly and heavily.
A a handful StudiesFor example, they discovered that there are people. Alcohol use disorder (Inability to control or stop problem drinking) Usually, “good” and “bad” bacteria in their gut are imbalanced. This is called dysbiosis and is associated with more inflammation and disease in general, Dr. Hsu said.
Heavy drinkers with dysbiosis may also have “more leaky,” or more porous, intestinal linings, Dr. Leggio said. A healthy gut lining acts as a barrier between the inside of the gut — full of microbes, food and potentially harmful toxins — and the rest of the body, he said.
Dr. Hsu added that when the intestinal lining is broken, bacteria and toxins can enter the bloodstream and flow to the liver, which can cause liver inflammation and damage.
Primary research An unhealthy gut can also contribute to alcohol cravings, says Dr. Jasmohan Bajaj, a hepatologist at Virginia Commonwealth University and Richmond VA Medical Center.
as if 2023 studyFor example, researchers looked at the microbiomes of 71 people between the ages of 18 and 25 who did not have an alcohol use disorder. Those who reported frequent binge drinking (It is defined as (4 or more drinks in two hours for women or five or more drinks for men) had microbiological changes associated with greater alcohol consumption. That study was also added. Previous research They found that heavy drinking was associated with major blood clots.
None of these studies have confirmed that alcohol causes dysbiosis in humans. The relationship is clearer in animal studies, but in human studies it is more difficult for researchers to control for factors such as diet and other health factors.
What about those who drink less?
Federal guidelines Define moderate drinking No more than two drinks a day for men or one drink a day for women. According to Jennifer Barb, a clinical bioinformatics scientist at the National Institutes of Health, there is very little research on how this amount of alcohol affects your gut microbiome.
Scientists they have found Compared to non-drinkers, low-to-moderate drinkers have more diverse gut microbiomes—a trait generally associated with a healthier gut. This could be due to other dietary or lifestyle factors, or something in the alcoholic beverages could benefit the microbiome — even if it’s not ethanol, Dr. Barb said.
as if 2020 study Among 916 women in Britain who drank two or fewer drinks a day, for example, researchers found that red wine drinkers — or, to a lesser extent, white wine — had different gut microbes than nondrinkers. No such link has been found with beer or alcohol. The researchers hypothesized that red wine’s high concentration of polyphenols compounds found in grape skins might explain their effect.
But you don’t need alcohol to get it PolyphenolsJohn Crean, a neuroscientist at the University of Cork in Ireland who studies the microbiome – which is found in grapes and most fruits and vegetables, as well as many herbs, coffee and tea.
In general, consuming a variety of plant-based foods and fermented foods such as yogurt, kombucha, and kimchi also improves microbiome diversity.
Can cutting down on alcohol improve gut health?
Researchers they have He looked In the microbiomes of people treated for alcohol use disorder, within two to three weeks after they stopped drinking, Dr. Barb said, the gut bacteria began to show signs of recovery, and so did their gut lining. Less “flowingHe said. But, she adds, it can also improve gut health, as people treated for alcohol use disorders often start eating healthier and sleeping better.
It’s not clear how — or even if — stopping or reducing alcohol affects the microbiomes of moderate drinkers, Dr. Leggio said. But we know that Alcohol can cause It can increase your risk of acid reflux, inflammation of the stomach lining and gastrointestinal bleeding, and several types of cancer, including those of the esophagus, colon, and rectum.
So “there’s no question,” says Dr. Lejo, that drinking less is a worthwhile endeavor for your health.