Woman whose belly brews its own alcohol

It took seven trips to the hospital before the mystery was finally solved...
07 June 2024

Interview with 

Rahel Zewude, University of Toronto


A pint of beer.


Now, I'm sure many of us have claimed to have had an upset stomach when we’ve had a few too many glasses of wine. But that is literally the case for some people with a very rare condition called auto-brewery syndrome. It happens when a person’s digestive system produces alcohol through the fermentation of ingested carbohydrates and - if not managed properly - it makes them drunk. To find out more, we put in a call to Rahel Zewude at the University of Toronto. One of Rahel’s patients developed the syndrome that led to dangerously high blood alcohol levels, way over the drink driving limit. She’s written up the case in the Canadian Medical Association Journal…

Rahel - So this patient is a 50-year-old woman who had intermittent presentations throughout two years leading to seven emergency room visits with slurred speech, gait imbalance leading to multiple falls, and was found to have high blood alcohol levels at her emergency room assessments despite her being adamant that she was not consuming any alcohol.

Chris - So what did the casualty officer, the attending physician, conclude on those occasions when the woman was seen?

Rahel - So in her six emergency room visits the conclusion was that she was indeed intoxicated with alcohol and she was not being forthcoming about her alcohol use. She was evaluated by three different psychiatrists during those visits. Despite her being consistent and her husband also providing the same history of no alcohol use, she was discharged with a diagnosis of alcohol use disorder and advised to stop drinking. But on her seventh visit, the emergency room physician gave her the diagnosis of probable auto brewery syndrome.

Chris - And what's auto brewery syndrome?

Rahel - Auto brewery syndrome is a syndrome characterised by endogenous fermentation of alcohol that occurs in the gut. So most typically fungus in the gut starts to convert carbohydrates into alcohol and result in high blood alcohol levels that then lead to intoxication.

Chris - And when you say high blood alcohol levels, how high were the blood alcohol levels in this lady? Would she be done for drink driving if she was behind the wheel of a car, for example?

Rahel - Oh yeah. She was absolutely way over the limit, the legal limit for driving in Canada. The highest level was 61 millimoles per litre. And to sort of give you an estimate, when you get to 86 and over millimoles per litre of blood alcohol level. That is considered fatal levels of blood alcohol.

Chris - So she was almost at the point of lethality with alcohol that she'd effectively brewed in her own belly? Why did she end up with an abdomen capable of intoxicating her?

Rahel - The currently understood pathophysiology for this syndrome involves multiple factors. The main one is disruption of gut microbiome. So we all have bacteria that live in our gut and fungus also as part of our healthy gut flora. But in auto brewery syndrome, these alcohol fermenting fungi overtake as the predominant pathogens in the guts of the patients. That also has to coincide with other factors that can put them in a situation where they are having ineffective gut motility, so things like gastrointestinal diseases like inflammatory bowel disease, short gut syndrome have been implicated. Certainly, things like liver disease and a potential role of genetic predisposition, that could affect their ethno metabolism. So when all of these things line up perfectly in a metabolic storm and the patient is also ingesting high carbohydrate diet, then it could lead to auto brewery syndrome.

Chris - And how was she managed once you realised this was what was going on? How did you sort her out?

Rahel - After the diagnosis, the patient was referred to our clinic and the gastroenterologist clinic. She was treated with antifungal medication called fluconazole and started on a low carbohydrate diet with dietician assessment and follow up. She had had a few episodes of relapse, particularly in the context of increasing her carbohydrate intake after she finished the course of antifungal. But we had given her an additional course of antifungal which led to symptom resolution and she's now doing well without any medication, but continuing with a low carbohydrate diet.

Chris - So have you managed to rebalance her microbiome? Has she got the right spectrum of bugs in her guts now so that she's less at risk of this happening?

Rahel - We do suspect that because we did organise an oral glucose challenge and she did have an undetectable amount of glucose after ingestion of this 150 grams of glucose. So at that point, we felt that there was not any gut fermentation happening. But again, in light of how the pathophysiology of this disease involves multiple factors, we do still think that she continues to be at risk. So we try to minimise any empiric antibiotics and anything that could disrupt her gut microbiome again which could cause a relapse.

Chris - And how does she feel about all this? Because obviously she wasn't taken terribly seriously for the first six trips to casualty. It was only on the seventh a very bright person said, could something else be going on? So has she forgiven the doctors for dismissing her?

Rahel - She's very happy with the seventh emergency physician who believed her and helped her identify the diagnosis, and then all of us who had been looking after her from infectious disease, gastroenterology, dietician to ensure that she continues to have a relapse-free life. But of course, on our first assessment, she was very emotionally distressed to even hear that this is all real and there are several reports of this and patients who have had this syndrome described across the world.


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