Feeling drunk without drinking? Scientists link rare syndrome to gut bacteria

• What happened: Researchers identified gut microbes that convert carbohydrates into ethanol inside the body
• Why it matters now: The findings offer clearer evidence behind auto brewery syndrome, a condition often dismissed or misdiagnosed
• What changes for people: Better diagnostics may emerge, helping patients experiencing unexplained intoxication symptoms
• Who is affected: A small number of individuals with gut microbiome imbalances triggering internal alcohol production

Scientists have uncovered new evidence explaining how a tiny group of people experience alcohol-like intoxication without consuming any liquor. The condition, known as auto brewery syndrome (ABS), appears to originate in the gut, where certain bacteria can convert everyday foods into ethanol that enters the bloodstream.

ABS has long puzzled doctors because symptoms mimic drunkenness despite zero alcohol intake. For patients, that can lead to stigma, confusion, and difficulty receiving appropriate treatment. The latest research provides an important scientific basis that could change how the condition is assessed.

How the body produces alcohol internally

According to findings published in the journal Nature, researchers documented cases where gut bacteria and metabolic processes transformed common carbohydrates such as bread, pasta, or sugar into ethanol, the same alcohol found in beer and wine.

Once produced, this ethanol travelled into the bloodstream, causing symptoms including slurred speech, impaired coordination, nausea, headaches, and fatigue.

Doctors note that diagnosing ABS remains challenging. The most reliable test involves closely monitored blood alcohol measurements, which are not widely available in routine clinics. This testing allows clinicians to confirm alcohol level spikes after food consumption.

A condition often misread or ignored

Because ABS is rare, experts say many patients struggle for years without clarity. Symptoms are frequently dismissed as dietary issues, mental health concerns, or suspected alcohol misuse.

Medical specialists studying the condition say the new evidence strengthens recognition within the health community. They highlight that understanding the gut microbiome's role in metabolic diseases is becoming a major research frontier.

Why this matters for the public

While ABS affects only a small number of people, the discovery has broader importance. Gut microbiome research is revealing how bacteria influence digestion, immunity, and neurological functions. Conditions once considered obscure are now understood through more precise biological models.

Doctors warn that individuals should not self-diagnose. They advise consulting gastroenterologists or metabolic specialists if experiencing unexplained symptoms related to balance, cognition, or alcohol test results.