Imagine feeling drunk without ever touching a drop of alcohol. For people with a rare condition called auto-brewery syndrome (ABS), this isn’t imagination; it’s real life. Now, scientists are learning why it happens and how to treat it, giving hope to those who have suffered in silence for years.
Researchers from Mass General Brigham, working with UC San Diego, have discovered certain gut bacteria and biological pathways that can actually turn the food you eat into alcohol inside your body. Published in Nature Microbiology on January 7, their study sheds light on a condition often misunderstood or misdiagnosed.
How auto-brewery syndrome works
ABS happens when specific microbes in the gut ferment carbohydrates from your food and produce ethanol, the same alcohol found in beer, wine, and spirits. Our bodies naturally make small amounts of alcohol while digesting food, but normally the liver swoops in and clears it out before it can cause anything noticeable. But in people with ABS, alcohol levels can rise high enough to make them feel drunk, even if they haven’t had a single sip.
Because the condition is extremely rare, and testing is complicated, many patients go years without a proper diagnosis. Clinicians are often unfamiliar with ABS, and the most reliable test, carefully supervised blood alcohol measurements over time, is not widely available. Meanwhile, patients may experience confusion, embarrassment, and serious consequences from unexplained drunkenness.
The Consequences of Misdiagnosis
Living with undiagnosed auto-brewery syndrome (ABS) can be incredibly tough. Many people feel isolated or even judged by friends and family who don’t realise what’s happening. The condition can even lead to real-life problems like legal trouble from unexplained intoxication, traffic incidents, or difficulties at work. The emotional impact is just as heavy, leaving patients feeling powerless, frustrated, and unfairly accused of drinking when they haven’t touched a drop.
Investigating the Gut Microbes
To uncover what triggers auto-brewery syndrome (ABS), researchers studied 22 patients, their 21 symptom-free household members, and 22 healthy volunteers. Stool samples during flare-ups revealed a surprising culprit: the patients’ gut bacteria were churning out far more alcohol than normal.
A few bacteria, like Escherichia coli and Klebsiella pneumoniae, appeared to fuel this process. During episodes, patients also showed sudden spikes in enzymes that turn food into alcohol, explaining how they could feel intoxicated without drinking. But even with these findings, figuring out exactly which mix of microbes is responsible for each person’s symptoms is still tricky and takes a lot of time.
Faecal Transplants Bring New Hope
In one striking case, a patient who hadn’t improved with standard treatments finally found relief after a faecal microbiota transplant. As their gut bacteria changed, symptoms faded and returned when the bacteria shifted back, clearly pointing to the microbiome as the cause. After a second transplant and a different antibiotic prep, the patient stayed symptom-free for more than 16 months.
“These results show how powerful microbiome-based treatments could be,” said Dr Elizabeth Hohmann of Mass General Brigham. “Pinpointing the bacteria behind ABS could lead to faster diagnosis, better treatments, and a real improvement in patients’ lives.”
Looking Ahead
Dr Hohmann and her colleagues at UC San Diego are now expanding their research to study faecal transplants in eight additional ABS patients. Researchers hope that these studies will show whether tweaking the gut microbiome could actually treat ABS and finally put an end to the years of confusion, misdiagnosis, and social stigma that so many patients face.
Though rare, this research sheds light on how our gut can secretly affect our health. It provides validation and the first genuine hope for relief for those who have been perplexed by inexplicable intoxication for a long time.
