Auto-Brewery Syndrome

This rare medical condition prompts the gut to ferment alcohol

Auto-brewery syndrome is a condition in which an overgrowth of yeast in the gut causes carbohydrates to ferment into ethanol. Patients with the condition can become intoxicated without ingesting any alcohol; all it takes is food.

“The obvious risk factor as it relates to this diagnosis is elevated blood alcohol levels that impair judgment while driving or operating machinery,” said Jeff McCombs, DC, author of The Everything Candida Diet. “Additional considerations would be passing out and possible long-term health implications such as chronic intestinal wall distention with a slight chance of perforation. This syndrome can be complicated by constipation, irritable bowel syndrome and excessive fermentation due to candida or other yeast organisms.”

Recent Cases 

A few cases of auto-brewery syndrome have been recorded in the United States. The most recent involved a 35-year-old teacher from upstate New York whose blood alcohol content read four times the legal limit when she was stopped by a police officer in fall 2014.

The woman had ingested four alcoholic beverages between noon and 6 p.m. To prove that auto-brewery syndrome was what caused her apparent “drunkenness,” her attorney forensically established that her blood alcohol content should have registered between 0.01 and 0.05.

The defense provided the court with blood samples taken on three separate occasions within a 12-hour period in which the defendant was monitored by two registered nurses and a physician assistant. The tests produced a blood alcohol level that was double, triple and quadruple the legal limit-even though the defendant wasn’t consuming alcohol during the observation. The judge dismissed the charges. The silver lining is that the woman now knows she has the condition and its potential implications.

One of the few research studies on the topic concluded that endogenously produced ethanol as a cause of a motorist’s intoxication lacked merit due to deficiencies in the design and lack of suitable control experiments in prior studies.

In other cases, auto-brewery syndrome appeared to be a byproduct of short bowel syndrome-such as in the case of a young girl who began showing signs of alcohol intoxication at age 3. On one occasion, a blood test indicated her ethanol concentration was 15 mmol/L. Candida kefyr was found in cultures of her gastric fluids. Researchers determined that these findings were linked to the consumption of a carbohydrate-rich fruit drink.4

Medical Management

A patient with auto-brewery syndrome requires careful surveillance in order to identify the factors at work and the most appropriate treatment.

“The best practices approach for establishing [auto-brewery] as a diagnosis would be placing the person in a hospital setting, where their diet and response to sugars could be measured and observed through blood tests, vitals and symptoms,” according to Cordell & McCarthy. In these documented cases, auto-brewery syndrome was treated with relevant pharmacotherapy and patients adhered to a restrictive diet. Because it is still such a unique and understudied condition, more research is necessary to determine a definitive cause and the best methods of treatment.


Cordell B, McCarthy J. A case study of gut fermentation syndrome (auto-brewery) with Saccharomyces cerevisiae as the causative organism. IJCM. 2013;4(7).