A rare medical condition called auto-brewery syndrome (ABS) turns the carbohydrates a person consumes into alcohol, making them intoxicated without drinking. So, for instance, if you develop ABS, your breath will smell like alcohol, you’ll feel dizzy, and you may say things you’ll regret later even though you didn’t drink.

What makes this rare syndrome particularly dangerous is that it isn’t widely known to the general public or even within the medical community. As a result, a patient may experience a lot of physical and mental distress by the time the condition is diagnosed. Imagine showing up to work intoxicated. Will your boss believe you when you tell them you only had lunch?

Researchers from the University of Toronto recently released the case study of a 50-year-old woman who suffered from ABS. The study reveals valuable insights about this rare condition, including the treatment methods, and the challenges a patient faces.

“ABS patients have suffered devastating medical and non-medical consequences. There are prior reports from a patient who sustained a brain bleed from a fall that occurred during intoxication from ABS. Moreover, including our patients, several patients had to take time off work and some of them lost their jobs as a result of this syndrome,” Dr. Rahel Zewude, lead study author and an expert on infectious diseases at the University of Toronto, told ZME Science.

The root cause of auto-brewery syndrome

Auto-brewery syndrome (ABS) was first described in a 1948 report, in a five-year-old Ugandan boy. The child underwent an emergency abdominal surgery and the surgeon noted an alcoholic smell emanating from his stomach contents. 

As the child was not known to consume any alcohol, the doctors suspected his body likely fermented the sweet potato meal he had earlier that day into alcohol. Cases that emerged in the following years confirmed this theory. 

Scientists discovered that ABS develops when microorganisms, especially fungi that inhabit our gut (such as Saccharomyces cerevisiae and Candida species including C. albicans and C. glabrata) start fermenting alcohol from the carbohydrates we ingest in our meals. 

“ABS is thought to occur partly due to gut microbiome disruption where fungi that ferment alcohol become the predominant organism in the gut ahead of other non-fermenting bacteria. This gut microbiome disruption can occur as a result of frequent or prolonged courses of antibiotics,” Zewude said.

However, there could be several other factors at play, and the syndrome likely occurs when these factors emerge at once at a time of high carbohydrate meals. 

For instance, gastrointestinal illnesses such as Crohn’s disease and ulcerative colitis, as well as liver disease have also been identified as risk factors for ABS. Moreover, genetic predispositions can also affect ethanol metabolism and contribute to the occurrence of this rare syndrome.

The ABS case study and treatment

The anonymous woman was 48 years old when she started experiencing symptoms of ABS. She felt lethargic, had slurred speech, and, an alcohol smell on her breath. When she visited the emergency department (ED) at her family physician, she was diagnosed with alcohol intoxication.

But the woman hadn’t consumed any alcohol in recent years. Over the next two years, she visited ED multiple times. The doctors performed brain scans and prescribed her medications to cure alcohol addiction. Meanwhile, three psychiatrists also separately assessed her for alcohol use disorder.

“She scored zero on the CAGE (Cut, Annoyed, Guilty, and Eye) screening questionnaire for alcohol use disorder,” the study authors note. 

Finally, after two years and on her seventh ED visit a physician suggested an ABS diagnosis for the woman. She tested positive, received anti-fungal medications, fluconazole (100 mg, twice daily), and was started on a low-carbohydrate diet. Within two weeks of the medication, her symptoms completely resolved.

After one month she stopped taking fluconazole but adhered to a low-carb diet. However, after four months, when she began increasing her carbohydrate intake, she had a relapse of ABS with similar symptoms. This episode was also treated with the same antifungal medication and a low-carbohydrate diet. 

After six weeks, the medication was discontinued. However, doctors performed some diagnostic endoscopic procedures, and based on the results they gave some probiotics to the woman to restore normal gut microbiome activity. The patient hasn’t shown any symptoms of ABS in the last six months. 

“We advised her to gradually increase her carbohydrate intake, and she will continue follow-up with our infectious diseases clinic, the gastroenterologist, and the dietitian,” the study authors said.

ABS is a rare condition but awareness is crucial

The woman had two years of delay in her diagnosis. Unfortunately, this is quite common for ABS patients due to limited awareness of the condition even among physicians. This delay is the root cause of the many devastating medical and social problems ABS patient faces. 

However, awareness of ABS and its early diagnosis can save patients from many of these issues and the resulting distress.

“In disseminating this report to our colleagues and the general public, I hope this will help raise awareness of this underrecognized syndrome and help patients who may remain undiagnosed,” Zewude told ZME Science.

The study is published in the journal CMAJ.