sábado, junio 15

How Does Alcohol Affect Your Gut Health?

A frothy beer or glass of wine can enhance a meal and soothe the mind. But what effect does alcohol have on the billions of microbes living in your gut?

As with much of microbiome science, «there’s a lot we don’t know,» said Dr. Lorenzo Leggio, a physician-scientist who studies alcohol use and addiction at the National Institutes of Health. Health.

That said, it’s clear that happy microbes are essential for good digestion, immune function, and gut health. And as scientists begin to explore the impact of alcohol consumption on your gut, they’re realizing that overdoing it could have unfortunate consequences.

Most of the available research on alcohol and the microbiome has focused on people who drink regularly and heavily, said Dr. Cynthia Hsu, a gastroenterologist at the University of California, San Diego.

A handful of studies, for example, have shown that people with alcohol use disorder (inability to control or stop problem drinking) often have an imbalance between «good» and «bad» drinking. bacteria in their intestines. This is called dysbiosis, and it’s usually associated with greater inflammation and disease than a healthier microbiome, Dr. Hsu said.

Heavy drinkers with dysbiosis may also have «leakier» or more permeable intestinal linings, Dr. Leggio said. A healthy intestinal lining acts as a barrier between the inside of the gut — filled with microbes, food and potentially harmful toxins — and the rest of the body, he said.

When the intestinal lining breaks down, bacteria and toxins can escape into the bloodstream and travel to the liver, Dr. Hsu added, where they can cause inflammation and damage to the liver.

Preliminary research suggests that an unhealthy gut might even contribute to alcohol cravings, said Dr. Jasmohan Bajaj, a hepatologist at Virginia Commonwealth University and the Richmond VA Medical Center.

In a 2023 study, for example, researchers examined the microbiomes of 71 people aged 18 to 25 who did not suffer from alcohol use disorders. Those who reported more frequent binge drinking (defined as four or more drinks in about two hours for women, or five or more drinks for men) had microbiome changes that correlated with cravings for more alcohol. important. This study also adds to previous research that found excessive alcohol consumption was associated with greater blood markers of inflammation.

However, among these studies, none have proven that alcohol causes dysbiosis in humans. The link 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 issues.

Federal guidelines define moderate drinking as no more than two drinks per day for men or one drink per day for women. There is very little research on how this amount of alcohol consumption affects your gut microbiome, said Jennifer Barb, a clinical bioinformatics researcher at the National Institutes of Health.

Scientists have found that, compared to those who don’t drink at all, people who drink at low to moderate levels have a more diverse gut microbiome – a characteristic generally associated with a healthy gut. This could be attributed to other diet or lifestyle factors, or it could be that something in alcoholic beverages could be beneficial to the microbiome — although it’s probably not ethanol, said Dr. Barb.

In a 2020 study of 916 British women who drank two glasses or fewer per day, for example, researchers found that those who drank red wine – or, to a lesser extent, white wine – had greater diversity intestinal microbial health than those who did not drink it. No such link has been found with beer or alcoholic beverages. The researchers hypothesized that polyphenols, compounds found in grape skins and present in high concentrations in red wines, could explain their results.

But you don’t need alcohol to find polyphenols, said John Cryan, a neuroscientist who studies the microbiome at University College Cork in Ireland: They’re also found in grapes and most other fruits and vegetables. , as well as in many herbs, coffee and tea. .

In general, eating a variety of plant-based foods and fermented foods like yogurt, kombucha, and kimchi can also improve microbiome diversity.

Researchers examined the microbiomes of people who were treated for alcohol use disorder and found that two to three weeks after the people stopped drinking, their gut microbes began to show signs of healing , Dr. Barb said, and their intestinal linings became healthier. less “leaky”. But, she added, people treated for alcohol use disorder usually start eating healthier and sleeping better, which can also improve gut health.

It’s not clear how — or even if — stopping or reducing alcohol consumption might influence the microbiomes of moderate drinkers, Dr. Leggio said. But we know that alcohol can cause acid reflux, inflammation of the stomach lining and gastrointestinal bleeding, he added, and can increase the risk of several types of cancer, including those of the esophagus, colon and rectum.

So there’s no doubt, Dr. Leggio said, that drinking less is a health-promoting effort.