Man Got Drunk Off 'Beer' Brewed by His Own Body After Yeast Took Over His Gut

A rare condition caused a man in the U.S. to produce a beer-like substance in his gut after eating carbohydrates, which made him drunk.

The ordeal saw the man pulled over by police for driving under the influence and convinced his family he was hiding a drinking habit, according to a case study published in the journal BMJ Open Gastroenterology earlier this year. The research on what is known as "auto-brewery syndrome" is due to be presented at the annual meeting of the American College of Gastroenterology this month, according to New Scientist.

It all started around January 2011, when the otherwise healthy 46-year-old was hit with symptoms including dizziness, brain fog and uncharacteristic aggression.

Doctors couldn't work out what was wrong, and he was referred to a psychiatrist who prescribed him antidepressants in 2014.

But his symptoms persisted, and one morning he was pulled over by police for drink-driving. The man insisted he hadn't had any alcohol. But a blood alcohol test told a different story, suggesting he had consumed 20 standard alcoholic drinks, and he was arrested.

His aunt, who had heard of similar cases where people acted inebriated despite claiming not to have consumed alcohol, urged him to have more tests.

Doctors found the fungus Saccharomyces cerevisiae, or brewer's yeast, in the man's stool sample. The fungus is commonly used in brewing to turn carbohydrates into alcohol, and was kicking off this process in the man's digestive system, causing his alcohol blood levels to spike without him drinking.

In a test for auto-brewery syndrome, the man was asked to eat a meal heavy in carbohydrates. His blood alcohol levels rose after the meal. Doctors prescribed him with anti-fungal medication, and told to stop eating carbohydrates.

However, his symptoms of inebriation returned, causing him to hit his head and suffer bleeding in his skull. Large amounts of alcohol were once again found in his system. He insisted he hadn't been drinking, but doctors didn't believe him.

The man found new hope after he visited the gastroenterology department at Richmond University Medical Center in New York. Physicians confirmed fungal yeast had formed in his upper small bowel and a pouch linking the junction of his small and large intestines. They learned the patient had worked for a construction company and helped to repair houses contaminated with mold, which they believe explained his condition.

The man took a different course of anti-fungal medication, and was ordered by doctors to stop eating carbohydrates for six weeks. Around a year and a half after he first visited Richmond University, he no longer experiences symptoms and can once again eat normally.

The condition was likely triggered by a prolonged course of antibiotics for a thumb injury, which changed the make-up of his gut bacteria, doctors believe.

Dr. Fahad Malik, who treated the man when he was a physician at Richmond University Medical Center, told New Scientist the patient "was extremely happy when he started to recover, because for years, no one believed him.

"The police, doctors, nurses and even his family told him he wasn't telling the truth, that he must be a closet drinker," he said.

"Now he is off antidepressants, he's back at work and he's finally getting on with his life," Malik said.

Malik told Newsweek: "The most surprising finding was how functional the patient was with such a high the blood alcohol. He had developed a high tolerance level to the alcohol."

He argued the case study shows patients should be believed when they say they are not drinking.

Malik highlighted the earliest symptoms of ABS can include mood changes, delirium, and brain fog rather than symptoms of alcohol intoxication.

This article has been updated with comment from Fahad Malik.