What is auto-brewery syndrome and how it happens

A 50-year-old woman would suddenly fall asleep multiple times while getting ready for work, slurring her speech and falling.

She went to emergency departments seven times in two years and was diagnosed with alcohol intoxication. But she hadn't had alcohol in years, which her family confirmed.

This week's issue of the Canadian Medical Association Journal includes a case report describing the rare condition, known as auto-brewery syndrome.

What is auto-brewery syndrome?

Auto-brewery syndrome, or gut fermentation syndrome, is thought to happen when the fungi or bacteria that colonize our intestines begin producing alcohol through fermentation. Basically, the gut becomes a mini-brewery.

The condition is rare, and doctors, law enforcement and legal officials may not be aware of it.

It can happen in the gastrointestinal system, mouth or urinary system.

What's the science behind it?

Dr. Prasanna Wickremesinghe, a gastroenterologist in New York who wrote an earlier case report on auto-brewery syndrome, has said fermented sugars or carbohydrates from a patient's diet can produce alcohol.

The alcohol is brewed internally, instead of at a brewery or winery.

In the latest case, Dr. Rahel Zewude, an infectious diseases physician at University of Toronto, and her co-authors said the fungi commonly identified in auto-brewery syndrome are Saccharomyces cerevisiae, or brewer's yeast, and candida species that can cause vaginal and skin infections.

How common is it?

Auto-brewery syndrome is uncommon because it requires an interaction between several factors, including a substantial overpopulation of fermenting micro-organisms and a high-carbohydrate diet, Zewude and her team said.

Other conditions such as diabetes, liver problems and inflammatory bowel diseases are associated with auto-brewery syndrome. Genetic predisposition may also play a role.

For the 50-year-old woman, doctors suspect her repeated antibiotics for urinary tract infections and acid-reducing medication for severe heartburn may have disrupted the gut microbiome.

"Auto-brewery syndrome is a rare condition," says one U.S. overview. "The disease has been identified in both male and female adults and children in many countries and is likely underdiagnosed."

The first published report was from 1948, on a boy with a ruptured stomach that smelled of alcohol, followed by one in Japan in 1952 and the U.S. in the 1980s, the CMAJ authors noted.

What's the impact on someone's life?

"Auto-brewery syndrome carries substantial social, legal and medical consequences for patients and their loved ones," Zewude and her team wrote.

"Our patient had several [emergency department] visits, was assessed by internists and psychiatrists, and was certified under the Mental Health Act before receiving a diagnosis of auto-brewery syndrome, reinforcing how awareness of this syndrome is essential for clinical diagnosis and management."

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The woman had repeated urinary tract infections over five years that were treated with antibiotics, as well as gastrointestinal reflux that was also treated. She told doctors she used to drink a glass of wine on holidays, but had stopped for religious reasons.

When the woman repeatedly went to the emergency room with slurred speech, the smell of alcohol on her breath and falling from sleepiness, she was discharged, with a diagnosis of alcohol intoxication, despite saying she never drank.

Tests showed no head injuries.

Psychiatrists offered care for addiction medicine before the possible diagnosis of auto-brewery syndrome. She was prescribed antifungal medication, referred to a gastroenterologist with follow-up at an infectious diseases clinic and a dietitian who advised a low-carb diet until ethanol could no longer be measured.

After each visit to emergency, the patient needed a week or two off work because of lethargy and drowsiness. She ate little, and the lethargy and appetite would improve then recur after a month or two, the paper's authors said.

In a previous U.S. case, Donato Giannotto's gut produced alcohol at very high levels, occasionally reaching eight times the legal limit for inebriation. He suffered from seizures, found himself in and out of hospitals and even developed acute pancreatitis, which is usually seen in people with alcohol use disorder.

Giannotto's wife, Michelle, described calling the husband's endocrinologist crying and begging for help to find a doctor up on the syndrome and how to treat it.

There is no standardized way to diagnose the condition, the CMAJ authors said.