Inside a rare syndrome that makes you drunk — without consuming any alcohol

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Imagine feeling intoxicated — and tests show that you are — yet you didn’t drink any alcohol.

That’s what happened to Scott Evenson. As he told me during a recent episode of WBUR’s On Point, he clearly remembers one night in 2024 when he was at a church function and ate some pasta. About an hour later, his wife Karen Evenson noticed he was staggering.

“He couldn’t stand up straight,” Karen said. “Tried to sit him down, get him drinking some water, he fell.”

Karen took Scott to a hospital where tests put his blood alcohol level at 0.345 — more than four times the legal driving limit. The doctors told them Scott shouldn’t even be functioning.

“They couldn’t believe that,” Scott said. “And I certainly wasn’t functioning well, but I was alert and communicative. It seemed really bizarre.”

Even stranger, this had happened to Scott before. Everyone he and his wife consulted assumed Scott was secretly drinking.

Then Scott was diagnosed with a rare condition called auto-brewery syndrome. It’s a disorder that occurs when the microbes in your body ferment carbohydrates and other sugars into alcohol.

“The body really produces its own ethanol,” said Dr. Bernd Schnabl, professor of medicine and co-director of the San Diego Digestive Diseases Research Center at the University of California at San Diego School of Medicine. “The ethanol is then absorbed into the bloodstream. These people can develop symptoms of intoxication. And without drinking.”

The existence of this condition, and emerging research on how the gut microbiome may affect human behavior, could have ramifications for the criminal legal system. Researchers have coined the term “legalome” — essentially arguing that a better understanding of how our microbes influence our actions should prompt a reconsideration of criminal liability and punishment.

As Schnabl explains auto-brewery syndrome, everyone makes a form of alcohol in their gut. But some people appear to have an imbalance in the gut microbiome that causes more alcohol to be produced than the body can metabolize. The alcohol then enters the bloodstream and creates intoxicating effects.

He said little is known about the disorder, including what triggers the microbiome imbalance. Current theories include antibiotics and high-carbohydrate meals. Schnabl is studying 22 patients to learn more.

It’s also unclear how many people may have auto-brewery syndrome and how to treat it. Two tests can confirm the diagnosis. But both require patients to be monitored, typically in a hospital, with repeated testing of their blood alcohol levels.

The typical first step in treatment is a strict low-carbohydrate diet, supplemented with either antibiotics, probiotics or antifungal medications. Schnabl is also trying fecal microbiota transplants, in which doctors transplant stool from a healthy donor to the patient. The idea is to rebalance the person’s gut microbiome. So far, he said patients seem to respond well to the transplants.

A main obstacle to diagnosing and treating the condition, Schnabl said, is increasing awareness — especially among health care providers.

Barbara Cordell knows this all too well. She noticed her husband’s symptoms decades ago and started doing extensive research. Eventually he improved with diet restrictions and antifungal medications.

“We do use the word ‘cure’ with him now,” said Cordell, who founded and leads an organization that advocates for people with auto-brewery syndrome.

Cordell said over the past 15 years, she’s been contacted by more than 3,000 people who think they have the syndrome and about 300 who have been diagnosed by a medical provider.

While Cordell spends a lot of time educating medical professionals about auto-brewery syndrome, she said it’s been an even tougher sell to the criminal legal system.

Cordell has testified in about 10 cases involving people accused of alcohol-related crimes, such as drunk driving. She said judges haven’t necessarily embraced the syndrome or written any precedent-setting rulings, but four cases have been dismissed.

Joe Masurak, the defense lawyer in one of those cases, said it’s unlikely that auto-brewery syndrome will become a widespread legal defense in drunk driving cases. Masurak, who practices law in New York, said convincing the courts that someone’s body is naturally producing high blood alcohol levels requires expensive — and extensive —  forensic testing and medical monitoring. He doubts many people will attempt this and believes it will take time for both the medical research and the courts to catch up.

“It’s going to be years down the road,” Masurak said. “You’re looking at a new area of medicine.”