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Can gut microbes get you drunk and damage your liver

Can Gut Microbes Get You Drunk and Damage Your Liver

Imagine that you’re a police officer. You spot a car ahead, which is swerving. You pull the driver over, and they are intoxicated. With slurred speech, she swears that she hasn’t had a drop of alcohol all day. Would you believe her?

In 2016, a person who had a blood-alcohol level four times the legal limit was acquitted of their DUI charge after it was discovered that she had an extremely rare condition called “auto-brewery syndrome.” People with this syndrome carry microbes in their intestines that produce abnormally high levels of alcohol, which they create when they break down sugars and carbohydrates.

While the auto-brewery syndrome is an extreme example, it makes one wonder: Could intestinal microbes be influencing other health or behavioral traits? There is a new study published in Cell Metabolism, showing that an intestinal bacterium may cause fatty liver disease by producing high levels of alcohol.

Diseased liver, without drinking

I am intrigued by the roles intestinal microbes - known collectively as the microbiome – play in human health. I think that all of us have realized at one time or another, just how our microbiome affects our health, mood, and behavior.

The accumulation of excess fats in the liver can cause serious health problems, including inflammation, which can lead to cirrhosis (scarring), liver cancer, and even premature aging. Most people have long associated fatty liver disease with alcoholism; however, nonalcoholic fatty liver disease, which affects a surprising 80 to 100 million Americans, arises without excessive alcohol intake at all.

There appear to be multiple causes of NAFLD, such as obesity, insulin resistance, high cholesterol, or hepatitis C infection. Now, we may have identified another.

The discovery occurred when physicians identified a patient who was suffering from both auto-brewery syndrome and severe NAFLD. When researchers examined stool samples from the patient, they found a species of bacteria called Klebsiella pneumoniae. This particular strain of K. pneumoniae was making between four and six times the quantity of alcohol that strains of the same bacteria make in healthy people. This prompted Yuan and her team to examine a cohort of 43 other patients with NAFLD. They discovered that 61% of them possessed K. pneumoniae excreting unusually high amounts of alcohol. Among 48 healthy people, only 6% contained such bacteria.