Quirks & Quarks

Beer belly: A rare yeast infection makes the gut into a microbrewery

Auto-brewery syndrome occurs when a disturbance to the gut microbiome results in the fermentation of carbohydrates

Auto-brewery syndrome occurs when a disturbance to the gut microbiome results in the fermentation of sugars

Auto-brewery syndrome turns people into walking breweries (Aris Messini/AFP/Justin Sullivan/Getty Images )

Michelle Giannotto knew something was wrong with her husband Donato after he had an infection following a simple nose surgery. He was slurring his speech, had glassy eyes and would sleep for days. She had no idea it had anything to do alcohol until a few weeks later. 

After Donato had a seizure, which would turn out to be the first of many, he was rushed to the hospital where the attending physician pulled Michelle aside to tell her that her husband was suffering from alcohol withdrawal.

"It was very confusing and very frustrating because I knew that there was no alcohol being consumed, but yet I couldn't prove it," said Giannotto who'd been caring for Donato since his surgery.

I called my husband's endocrinologist crying one day and begged for help. And I said, 'Please find me a doctor. He's going to die. I don't want to bury him.'- Michelle Giannotto, Donato's wife

It turns out Donato was suffering from a rare, yet profoundly life-altering, syndrome in which a yeast or bacteria that colonizes the intestines begins producing alcohol. Effectively people are hosting a mini-brewery in their gut. It's called auto-brewery syndrome

These yeasts — a kind of fungus — act similarly to brewer's yeast in the gut, said gastroenterologist Dr. Prasanna Wickremesinghe in conversation with Quirks & Quarks guest host Torah Kachur. 

"These fungi are fermenting the sugars — these are carbohydrates — that the patient is eating," she said.

Wickremesinghe is a co-author on a new case report published this week in the British Medical Journal about one of the several patients he's treated who have auto-brewery syndrome. This syndrome isn't entirely new to science, but it's nearly unknown to physicians, law-enforcement and legal officials. 

The toll it can take on people's lives

For 20 months, Donato Giannotto's gut produced alcohol at very high levels, occasionally reaching eight times the legal limit for inebriation. He suffered from seizures, found himself in and out of hospitals and even developed acute pancreatitis, an inflammation of the pancreas caused by elevated blood alcohol levels, that is usually only seen patients who are alcoholics.

His wife Michelle had to become Donato's permanent caretaker and advocate, trying to find him a doctor who knew about the syndrome and how to treat it. 

"I called my husband's endocrinologist crying one day and begged for help. And I said, 'Please find me a doctor. He's going to die. I don't want to bury him.' The endocrinologist said, 'Let me make some phone calls. I'll call you back,'" she said.

Donato Giannotto (right) was treated for auto-brewery syndrome where his gut ferments carbohydrates — producing his own alcohol — thanks to his wife Michelle (left) who tirelessly advocated for him even when many doctor's didn't believe him. (Michelle Giannotto)

Within a few hours, the endocrinologist called back and told her to make an appointment with Wickremesinghe who had heard of the syndrome, but had never seen a case himself in his decades of practice. Donato would become the first of 10 patients Wickremesinghe would treat. 

The toll auto-brewery syndrome can take on patients' lives is "huge," according to Wickremesinghe.

Michelle said Donato often wouldn't even notice he was inebriated even when his blood alcohol levels were above the legal limit. Wickremesinghe thinks there is a possibility this syndrome isn't as rare as the number of known cases would suggest and suspects it may be significantly underdiagnosed

"These patients have to be very careful about driving a motor vehicle — losing control and being in an accident — looking, sounding and smelling inebriated," said Wickremesinghe.

Added to these risks are social consequences.

"People think you're a closet drinker," she said.

Wickremesinghe even described one patient who'd he diagnosed with auto-brewery syndrome after he'd been arrested for drinking and driving. The authorities deciding this patient's fate didn't believe the medical data, and he has spent the last two years in jail. 

Treatment to suppress the syndrome 

To diagnose auto-brewery syndrome, patients undergo a carefully supervised carbohydrate test in the hospital, to make sure any alcohol that shows up comes from the gut and not a bottle. 

In order to figure out how to best treat a patient like Donato, Wickremesinghe collected his gut secretions to identify the microbial species responsible for turning the carbohydrates he ate into alcohol. That way, Wickremesinghe could determine which antifungal medicine would work best to get rid of that particular strain.

Wickremesinghe also instructs his patients to go on a ketogenic diet — eliminating all carbohydrates from their diet, and puts them on a probiotic — first a single strain, then a multistrain probiotic — to recolonize the gut with good gut bacteria.

Wickremesinghe says, despite these treatments, patients often relapse after taking antibiotics again or experience some other trigger that allows the fungi to grow all over again.


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