For most of us, the capacity for accurate self-reporting tends to decline after a few drinks, yet when a North Carolina man was arrested for drunk driving and claimed he hadn’t imbibed, he was telling the truth.
Still, he was anything but sober.
Tests eventually revealed that the man, who is the subject of a study published in 2019 in BMJ Open Gastroenterology, had a rare condition called auto-brewery syndrome.
This can occur when the growth of intestinal yeast outpaces the body’s ability to process it, leaving the excess to ferment in the bowel. The fermentation produces what is, in effect, the body’s own beer.
“Candida, or other intestinal yeast, can take simple sugars or refined carbohydrates and turn them into alcohol,” explains functional-medicine physician Gregory Plotnikoff, MD.
A healthy gut microbiome includes several species of yeast, but overgrowth is not uncommon — especially after a course of antibiotics. These drugs typically wipe out a range of good and bad gut microbes, but not yeast. Without the good microbes to maintain balance, yeast can grow unchecked. (For more on this, visit “How to Treat Candida Overgrowth”.)
When a surplus of yeast feeds on an excess of carbohydrates and sugar, this can trigger enough fermentation to raise the body’s blood-alcohol levels well beyond the legal limit for driving. It can also spur a range of other health effects, such as nonalcoholic fatty liver disease (NAFLD).
“I just saw someone who, without a drop of alcohol, had nearly exceeded the legal limit for alcohol in the body,” Plotnikoff says. “I went looking for auto-brewery syndrome to understand the cause for his quite severe NAFLD. He also suffers from severe bloating.”
Because this process usually endures over time, many sufferers adapt to high levels of blood alcohol, much as long-term alcoholics do. They may also display signs of inebriation that resemble drunkenness, which can be mistaken for dementia or other cognitive-health issues.
The treatment for auto-brewery syndrome involves an extremely low- or no-carbohydrate diet to starve the yeast, as well as antifungal medications and probiotics. For the patient in the BMJ study, this approach helped reset his system. Eventually, his blood-alcohol levels returned to normal.
Plotnikoff believes the condition may be more common than we think. “My sense is that we only say this is rare because we only look for this in the most egregious cases.”
This originally appeared as “Drunk . . . On Yeast Overgrowth?” in the October 2020 print issue of Experience Life.