Medical Mysteries Man who doesn't drink alcohol gets drunk eating carbs

It was morning when the man was pulled over by the police, who assumed he was driving under the influence.

- judith Tan

His blood alcohol level was found to be more than twice the legal limit - 200 milligrams per 100ml of blood (200mg/dL). Singapore's legal drink-driving limit is strictly enforced at 80mg/dL, or 0.08 per cent blood alcohol content.

The man, who was 46 at the time of the incident in 2014, also experienced brain fog, dizziness and memory loss - much like the symptoms an alcoholic exhibits.

But he told the police that not a drop of alcohol had ever passed his lips.

It was only after multiple consultations with various doctors in different specialities over a few years that he was diagnosed with auto-brewery syndrome (ABS).

ABS, which is also known as gut fermentation syndrome, is an extremely rare condition where bacteria and fungi in the gastrointestinal tract turn the carbohydrates in everyday foods into alcohol.

If left untreated, it can lead to alcoholic fatty liver disease.

There were fewer than 100 cases of ABS reported worldwide in a 2021 report, with the man being one known case in Singapore. His doctors did not identify him.

The rare metabolic condition made the news earlier in 2024 when a Belgian man with ABS had a drink-driving charge against him dismissed in court in April.

The 40-year-old proved that he has ABS, resulting in signs of intoxication. His lawyer told Reuters later that three doctors independently examined him and confirmed his condition.

The syndrome had been described in medical research for more than 50 years, but researchers are still learning more about it.

In ABS, the body has an unbalanced gut microbiome comprising bacteria, fungi and viruses in the intestines.

Different ABS patients have different triggers for the condition. For the Singapore man, his doctors believe the antibiotics he took for a thumb injury was his trigger.