UNC Health Talk

6 Ways Alcohol Can Damage Your Gut

Most of us know that drinking too much alcohol can have negative effects, from life-threatening situations such as alcohol poisoning and drunken driving to relationship problems and hangovers.

We even know that drinking is bad for our guts, both because too much drinking makes you sick to your stomach and can also lead to the dreaded “beer belly.”

But that’s just the start of the effects of alcohol consumption on gut health, says UNC Health gastroenterologist Tanvir Haque, MD.

“For most people, moderate consumption of alcohol is pretty safe, and it’s not likely to cause problems in your gut,” Dr. Haque says. “Moderate consumption means no more than one drink a day for women or no more than two drinks a day for men. But when your consumption gets to be more than one or two drinks a day, then you are more likely to have gut problems.”

Here are six of those potential problems:

1. Acid reflux.

Drinking alcohol relaxes the lower esophageal sphincter, which normally prevents acid in your stomach from backing up into your esophagus. The sphincter doesn’t work as well when it has been relaxed by alcohol, so you are more likely to experience acid reflux, commonly called heartburn, after drinking.

“Almost everyone experiences occasional acid reflux, and for most people it’s not a serious problem,” Dr. Haque says. “But for people who frequently drink too much, acid reflux can become a chronic and serious problem.” Over time, repeated acid reflux can lead to more serious conditions, such as Barrett’s esophagus or esophageal cancer. In some cases, people may need surgery.

2. Diarrhea.

Everyone has a mix of “good” and “bad” bacteria in their gut. Drinking too much alcohol disrupts the normal balance, increasing the bacteria that cause inflammation and irritation in the gut while decreasing the bacteria that aid in digestion. Excessive bad bacteria can lead to a “leaky gut,” in which gaps in the intestinal wall allow bacteria and other toxins into the bloodstream.

“To explain leaky gut, I tell patients to think of their intestinal lining as a brick wall. When there are cracks in the mortar between the bricks, water can leak through. In leaky gut, alcohol causes cracks in the ‘mortar’ of the intestinal wall.”

Excessive alcohol consumption leads to leaky gut, decreases gut absorption and increases the production of bile in the liver, all of which can lead to diarrhea, Dr. Haque says.

3. Gastritis.

Drinking too much alcohol disrupts the production of mucus that lines the stomach, which can cause the stomach lining to become inflamed. This condition is called gastritis. Symptoms of gastritis include abdominal pain, nausea and vomiting.

“Repeated episodes of gastritis can lead to more serious conditions such as ulcers, anemia or stomach cancer,” Dr. Haque says.

4. Bloating.

Alcohol consumption disrupts both the digestion of sugars and the balance of bacteria in the gut. It also leads to a shift in the gut’s normal fungal diversity, causing overgrowth of a type of yeast called candida. These shifts increase gas production in the gut, and that causes your abdomen to feel uncomfortably bloated.

Drinking any type of alcohol can lead to bloating, Dr. Haque says, but it is more commonly associated with beer than with wine or spirits.

5. Damage to the liver.

Heavy alcohol use can cause fat to build up in your liver. This is called alcoholic fatty liver disease, or alcoholic steatohepatitis. As the liver breaks down alcohol, toxins are created that can damage liver cells and promote inflammation. “These toxins, which are byproducts of alcohol digestion, cause inflammation in the liver. Additionally, when alcohol gets metabolized in the liver, it gets converted to and stored as fat,” Dr. Haque says.

People with alcoholic fatty liver disease usually don’t have symptoms, but over time it can lead to liver failure, liver cancer or cirrhosis. All of these are serious illnesses that can be life-threatening. In the most severe cases, a person may need a lifesaving liver transplant.

“The good news is that alcoholic fatty liver disease can be reversed if you catch it early enough” with routine bloodwork, Dr. Haque says. Lifestyle modifications such as reducing or eliminating alcohol consumption, eating a healthy diet and increasing your physical activity will help reduce the amount of fat in your liver and improve your liver health.

6. Damage to the pancreas.

Heavy alcohol use can also damage the pancreas. The pancreas metabolizes alcohol into toxic byproducts that damage the pancreatic ducts. In addition, enzymes that normally would be released into the digestive tract build up inside the pancreas and can begin to digest the pancreas itself. This causes a very painful inflammation of the pancreas called pancreatitis.

Alcohol-induced pancreatitis is most commonly found in people who have four to five drinks a day over more than five years. People who drink heavily and are also smokers have an even higher risk; they are four times more likely to develop acute pancreatitis.

“When there is damage to the pancreas, it’s a really big deal. That can be life-threatening,” Dr. Haque says.

Treatment for most cases of alcohol-induced pancreatitis includes a combination of measures, such as IV fluids and electrolyte replacement, tube feeding and alcohol cessation counseling. In the most severe cases, patients may suffer organ failure in the pancreas and possibly other organs, such as the colon and kidneys.

Cases like these are likely to require surgery followed by months in recovery. Chronic abdominal pain, diabetes and pancreatic cancer can be long-term complications of pancreatitis.


If you’re struggling with digestive problems, talk to your doctor or find a gastroenterologist near you.