Researchers have pinpointed specific gut microbes responsible for auto-brewery syndrome, a rare condition where people become intoxicated without consuming alcohol. The study identifies key bacteria and pathways that convert carbohydrates into ethanol in the bloodstream. Findings suggest potential for improved diagnostics and treatments, including fecal transplants.
Auto-brewery syndrome (ABS) has long puzzled doctors, causing individuals to show signs of drunkenness despite abstaining from alcohol. A new study reveals that certain gut bacteria ferment carbohydrates into ethanol, leading to elevated blood alcohol levels. Published on January 7 in Nature Microbiology, the research comes from a collaboration between Mass General Brigham and the University of California San Diego.
The condition arises when microbes in the digestive tract produce alcohol during normal food breakdown, far exceeding the trace amounts seen in healthy people. While rare, ABS often goes undiagnosed for years, resulting in social isolation, health issues, and even legal troubles from unexplained intoxication. Diagnosis typically requires supervised blood alcohol monitoring, which is not widely available.
To probe the syndrome's mechanisms, scientists examined stool samples from 22 ABS patients, 21 unaffected household members, and 22 healthy controls. During flare-ups, patient samples generated significantly more ethanol than those from others, pointing to distinct microbial activity. Analysis highlighted bacteria such as Escherichia coli and Klebsiella pneumoniae as primary culprits, along with elevated fermentation enzymes.
In a promising development, one patient experienced lasting relief after fecal microbiota transplantation, remaining symptom-free for over 16 months following a second procedure. "Auto-brewery syndrome is a misunderstood condition with few tests and treatments. Our study demonstrates the potential for fecal transplantation," said co-senior author Elizabeth Hohmann, MD, from Mass General Brigham's Infectious Disease Division.
These insights could pave the way for stool-based tests and targeted therapies. Hohmann and colleagues at UC San Diego are now testing fecal transplants in eight ABS patients, aiming to enhance diagnosis and quality of life for those affected.
