Her breath reeked of alcohol. She was dizzy, disoriented and weak, so much so that one day she passed out and hit her head on a kitchen counter while making lunch for her school-age children.

Yet not a drop of liquor had passed her lips, a fact that the 50-year-old Toronto woman and her husband told doctors for two years before someone actually believed her.

鈥淪he visited her family doctor again and again and went to the over two years,鈥� said Dr. Rahel Zewude, an infectious disease specialist at the University of Toronto.

Doctors found the woman鈥檚 alcohol levels could range between 30 millimoles per litre and 62 millimoles per litre 鈥� below 2 millimoles per litre is normal, Zewude said.

Alcohol levels of up to 62 millimoles per litre are extraordinarily high and would be considered life-threatening, even fatal, said Barbara Cordell, president of an advocacy association called  which provides patient education and does research on the unusual condition.

While no one she knows has had alcohol levels reach that level, many people can function at blood alcohol levels of up to 30 millimoles per litre or 40 millimoles per litre, Cordell said in an email.

鈥淚 know of over 300 people diagnosed with auto-brewery syndrome and we have over 800 patients and caregivers in our private Facebook support group,鈥� said Cordell, who was not involved in the new case.

鈥淧art of the mystery of this syndrome is how these people can have these extremely high levels and still be walking around and talking.鈥�

All of the emergency room doctors questioned the Toronto woman鈥檚 drinking habits, and she was examined by three different hospital psychiatrists who concluded that she did not meet criteria for the diagnosis of alcohol use disorder.

鈥淪he told doctors her religion does not allow drinking, and her husband verified she did not drink,鈥� said Zewude, who treated the woman and co-authored a report on the anonymous case that published Monday in the Canadian Medical Association Journal.

鈥淏ut it wasn鈥檛 until the seventh visit that an emergency room doctor finally said, 鈥業 think this sounds like auto-brewery syndrome,鈥� and sent her to a specialist,鈥� Zewude said.

Dr. Fahad Malik, a gastroenterologist at United Heath Services in Binghamton, New York, who currently has 30 patients with the disorder, said in an email that being treated with disbelief and ridicule is common for patients. He was not involved in the new case study.

鈥淢ost patients have been disregarded as 鈥榗loset drinkers鈥� or with behaviour conditions prior to diagnosis,鈥� said Malik, who is also a clinical assistant instructor at the State University of New York Upstate Medical University.

Extremely rare and frequently unrecognized

Auto-brewery syndrome, also known as gut fermentation syndrome, is an extremely rare condition in which bacteria and fungus in the gastrointestinal tract turn the carbohydrates in everyday food into ethanol. The  occurred in 1946 in Africa, when a 5-year-old boy鈥檚 stomach ruptured for no known reason. An autopsy found his abdomen filled with a 鈥渇rothy鈥� fluid smelling of alcohol.

Since 1974, 20 diagnosed cases of auto-brewery syndrome have been reported in English medical literature, according to an .  of auto-brewery symptoms have occurred in Japan, where the condition is known as meitei-sho, or 鈥渁lcohol auto-intoxication syndrome.鈥�

Auto brewery syndrome occurs when certain species of bacteria and fungi overpopulate a person鈥檚 gut microbiome, basically turning the gastrointestinal tract into a still apparatus.

Scientists believe the process takes place in the small bowel and is vastly different from the normal gut fermentation in the large bowel that gives our bodies energy.

While a number of pathogens can contribute, most cases are due to an overgrowth of two species of fungi: Saccharomyces and Candida. Candida lives on the body and in the mouth, digestive tract and vagina, often taking over when more beneficial bacteria are killed off by a round or two of antibiotics.

A July 2013 report  who had frequent bouts of unexplained drunkenness for years before being diagnosed with an intestinal overabundance of Saccharomyces cerevisiae, or brewer鈥檚 yeast, the same yeast used to make beer.

Many people with the syndrome can function with an enormous amount of metabolically generated alcohol in their system, sometimes only realizing it when they get in trouble with the law.

A North Carolina man in his late 40s was pulled over for what cops were convinced was drunk driving. He denied drinking despite a blood alcohol level of 0.2%, the equivalent of consuming 10 drinks an hour and about 2.5 times the legal limit.

鈥淚t鈥檚 not as rare as we think, it鈥檚 (just) rarely diagnosed,鈥� Cordell said. 鈥淚 believe many people may walk around feeling foggy and just think they are tired when they might be fermenting alcohol.鈥�

鈥楢 metabolic storm鈥�

There are risk factors for auto-brewery syndrome. Diabetes and liver disease can play a role as can gastrointestinal diseases such as inflammatory bowel disease and short gut syndrome, in which the small intestine is damaged or shortened, Zewude said. There may even be a genetic predisposition connected to how well a person metabolizes alcohol.

鈥淏ut all of these things have to collide at the perfect time,鈥� she said. 鈥淚t requires multiple risk factors interacting and creating a metabolic storm for this syndrome to emerge in an individual.鈥�

For Zewude鈥檚 Toronto patient, that metabolic storm began in her mid-40s when she started to have concurrent urinary tract infections, each treated with a round of antibiotics. Beneficial bacteria in her intestinal tract began to die off, allowing the fungi lying in wait to take over.

That much yeast needs fuel, which it gets from carbohydrates in the diet. By the time the woman was 48, her body was turning nearly every carb she ate into alcohol.

鈥淚f she didn鈥檛 eat many carbs, the symptoms weren鈥檛 so bad,鈥� Zewude said. 鈥淏ut then she might have a slice of cake or another big carbohydrate meal, which led to a rapid rise in her alcohol level. These were the times where she might be getting lunch ready for her kids and just fall asleep.鈥�

Treatment for auto-brewery syndrome begins with a course of fungicides prescribed after a biopsy or colonoscopy identifies the specific pathogens that have colonized the gut, Zewude said. Starting with a broad-spectrum fungicide can backfire.

鈥淎ntimicrobial resistance is an important part of the syndrome, because part of the reason people get this is because of the frequent antibiotic use that disrupts their gut,鈥� she said. 鈥淵ou need to start narrowly, and then if the patient becomes resistant to that fungicide, try others.鈥�

In addition to killing off the yeast, patients are expected to follow an extremely restricted low-carb diet. 鈥淣o carbs would be best, but it鈥檚 almost impossible to do that,鈥� Zewude said. Probiotics to build back beneficial bacteria can also help, she said.

Today, the woman is no longer taking antifungal medications, but she remains on a very low-carb diet after having a relapse. As each person鈥檚 experience is different, it鈥檚 important that patients stay in close touch with their doctors to manage their condition, Zewude said.

鈥淚n this case, the woman has a very supportive husband, who called me immediately when he began to smell alcohol on her breath again,鈥� Zewude said. 鈥淔or anyone dealing with the syndrome, it鈥檚 important that your spouse, friend, roommate or whatever, know the signs and symptoms and connect with physicians or bring the person to the emergency department when this occurs.鈥�