The Gut Yeast That Brews Ethanol From Every Carb You Eat

**Dr. Gabrielle Lyon** (0:00)
This person didn't drink any alcohol, but failed a breathalyzer test, and this is not folklore. In 2015, a judge in upstate New York dismissed a driving while intoxicated charge against a woman who registered a blood alcohol concentration more than four times the legal limit. This is a condition in which the gut itself produces intoxicating quantities of alcohol from the carbohydrates you eat. And after her defense demonstrated that her own GI tract was manufacturing ethanol. The condition has a name, auto-brewery syndrome. It registers on a breathalyzer. It registers on a blood alcohol test. And, which this blew my mind, it registers in the body as intoxication, brain fog, dizziness, disorientation. And today we go inside the distillery. And then I'm going to show you why this obscure diagnosis is really a story about muscle.
Drunk without a drop. The gut condition that can get you a DUI. Can you believe it? Picture a driver leaving dinner. Pasta, a basket of bread, soda clearly not on the forever strong plan, and an hour down the road flashing lights, a failed sobriety test, a breathalyzer, four times the legal limit. And here's the detail that should stop you cold on the amount of alcohol the driver actually consumed. That number is physiologically impossible.
No bar tab explained it. The alcohol was never poured. It was, get this, fermented inside the gut and absorbed into the bloodstream, exactly the way a round of shots at a bar would be.
Do you guys get this? This person didn't drink any alcohol, but he failed a breathalyzer test. And this is not folklore. It is not a courtroom stunt. I did not find this on the pages of a tabloid. In 2015, a judge in upstate New York dismissed a driving while intoxicated charge against a woman who registered a blood alcohol concentration more than four times the legal limit. And after her defense demonstrated that her own GI tract was manufacturing ethanol, her attorney tracked down the researcher, Barbara Cordell, and a physician who ultimately made the diagnosis. The charge did not survive the biochemistry, and this was in CBS News in 2015
The condition has a name, autobrewery syndrome. That's creative. And it earns a rigorous look, not because it's common, but because of what it exposes about the state of the gut and about a variable almost nobody thinks to defend. Now if you're new to this channel, I'm Dr. Gabrielle Lyon, and today we go inside the distillery, and then I'm going to show you why this obscure diagnosis is really a story about muscle. Okay, autobrewery syndrome. You'll also see it in the literature as gut fermentation syndrome or endogenous ethanol fermentation. This is a condition in which the gut itself produces intoxicating quantities of alcohol from the carbohydrates you eat. The research describes it as endogenous, which means from inside your body, production of ethanol by fermenting organisms living inside the GI tract.
This is not a new idea that someone invented for a TV segment. The earliest descriptions of endogenous gut fermentation trace back more than a century to case reports in the 1890s and the early medical literature on quote auto-intoxication and a cluster of Japanese case reports followed across the middle of the 20th century.
The foundational modern case study in the US was published in 2013, documenting a man in his 60s with years of unexplained, debilitating intoxication whose gut was colonized by brewer's yeast. That's the same organism used to make beer. And if you're into popcorn, we throw it on our popcorn. Here's the honest state of the science. And I want to be precise because precision really is the whole point of this platform. I'm hoping you don't just come from my jokes. The literature on auto-brewery syndrome is built almost entirely on case reports and small case series. What does this mean? This is thin evidence base. It doesn't mean that this condition is imaginary. It means that really it's understudied because it's not that common. And the reviewers who work on it argue it is almost certainly underdiagnosed rather than genuinely rare, which is something interesting to think about. It is simply not the first or the 15th explanation a clinician reaches for when a patient presents with intoxication. I mean, I remember when I worked in the emergency department and I was doing my psychiatric residency. If someone came intoxicated, we were thinking the obvious, alcohol. We were not thinking auto-brewery syndrome.
So what is happening here? There always has to be a mechanism. And research points to yeast. Most often, saccharomyces or a strain of Candida, such as Candida albicans, and another Candida name that I don't even want to try to pronounce for you, colonizing the gut in numbers far past what a defensible microbiome should tolerate. Meaning it's way out of control. In a balanced system, these organisms, they're minor players. In auto-brewery syndrome, they have taken over the gut. Then you eat. A carbohydrate load arrives, glucose, sucrose, refined starch, this could be any of your rice, pasta, you name it. And to those yeast, it is not just lunch, for example, for you, it is a substrate. It is a fuel source. They metabolize it through fermentation. And the by-product is ethanol. And that ethanol is absorbed across the intestinal wall into the bloodstream through the same pathway that handles that glass of wine at dinner.