Auto-brewery syndrome may cause intoxication without drinking

A new Nature Microbiology study reports that people with auto-brewery syndrome can have higher stool ethanol and altered gut microbes that produce alcohol; researchers say stool-based testing and enzyme-focused treatments are being explored as possible paths forward.

Auto-brewery syndrome (ABS) is a rare condition in which the body can produce alcohol internally, and affected people can appear intoxicated despite not drinking. The condition is stigmatized and likely undercounted. Researchers have long suspected that imbalanced gut microbes play a role, and a new study examined gut samples to seek clearer biological signals and possible diagnostic or treatment approaches. Key findings: - ABS is reported in at least about 100 people worldwide and can lead to social and legal consequences; stigma may cause mislabeling of cases. - The published study compared gut microbes from 22 people diagnosed with ABS, 21 household partners, and 22 healthy controls to look for differences linked to flare-ups. - During flare-ups, median stool ethanol levels were higher—about three times those of household partners—and patient stool produced more ethanol in laboratory tests. - Samples from people with ABS had higher amounts of microbes such as Escherichia coli and Klebsiella pneumoniae, and lab tests showed antibiotic treatment could reduce ethanol production; authors suggest targeting microbial fermentation enzymes rather than single species. Summary: The study provides laboratory and clinical signals that gut microbes and microbial enzymes are involved in episodes of internal alcohol production in ABS. Researchers note that stool-based measures and enzyme-focused approaches are being explored as potential avenues for further research, while the precise causes and optimal treatments remain undetermined at this time.