All you need to know about: auto-brewery syndrome

Discover essential insights about auto-brewery syndrome, a rare condition causing intoxication from gut-produced ethanol.

A small number of people in the world experience a strange condition in which they feel drunk, and exhibit signs and effects of drunkenness (like slurred speech and tipsyness), despite not having consumed any or very minimal amounts of alcohol.

This medical condition, known as auto-brewery syndrome (ABS) or gut fermentation syndrome, is rather rare, and occurs when bacteria or fungi in the gut produce high levels of ethanol, especially after a carbohydrate-heavy meal, causing symptoms of intoxication.

Instances of this condition were first reported in Japan in the 1950s, but it continues to be underdiagnosed. Apart from the physical effects, like stomach ache, nausea, vomiting, hangovers, and even alcohol poisoning when levels are too high, this syndrome can get in the way of normal life and also lead to serious legal and social consequences.

Here’s all you need to know about auto-brewery syndrome:

Our gut contains a wide variety of microbes, including some that produce alcohol, such as Saccharomyces cerevisiae, also known as brewer’s yeast. Usually, after consuming carbohydrate-rich food, these microbes produce a minuscule amount of ethanol, which, under ideal circumstances, is metabolised before it reaches the bloodstream.

However, in people with auto-brewery syndrome, these microbes – whether fungi or bacteria – produce ethanol at high rates, making it difficult for the body to clear it properly and efficiently.