By: Ross Federman
A bar I used to frequent serves a delicious frozen drink known as a “Constant Buzz.” It sounds like an appealing concept, a nice basal level of ongoing intoxication, but did you know that in some incredibly rare cases, individuals find themselves in this situation without any choice? Auto-Brewery Syndrome (or gut fermentation syndrome) is a disease whereby patients literally brew alcohol in their guts. Imagine not taking a single sip of beer, wine, or liquor, yet still constantly registering above the legal limit on any manner of blood alcohol or breathalyzer tests. This is the unfortunate case for those rare few that find themselves with this disorder.
How does it happen? It was a mystery for years. In fact, it’s likely that some may have been incarcerated, fired from jobs, suspended from school, you name it, all because they were drunk against their will with no explanation to offer as to their erratic behavior. Recently, we have gained significant insight into the nature of our gut microbiota and the profound role that it plays in human health. The microbiota is usually discussed in terms of the species of bacteria that comprise it; yet other microorganisms are present, as well. In most healthy microbiota, a small population of the commonplace fungal yeast species Saccharomyces cerevisiae lives in your gut with all the other microorganisms. S. cerevisiae is also known as “Baker’s Yeast” and is the species often simply referred to as “yeast” in the majority of baking and beer brewing applications. You and everyone around you likely have some S. cerevisiae hanging around in your guts, and the amount of it is largely kept in check by your immune system, other microorganism species, and competition for nutrients. However, in some rare cases, this population is not kept to the proper minimal levels and grows wildly out of control.
At the heart of this phenomenon is the fermentation process. It is found in both yeast and bacteria, though the specific fermentation products differ. In both cases, sugars or carbohydrates are broken down to carbon dioxide in order for the microbes to produce energy in an environment lacking oxygen (such as our guts). For bacteria, lactic acid is the second byproduct along with carbon dioxide, but in yeast, ethanol is produced in lieu of lactic acid. Thus by increasing the ratio of S. cerevisiae to bacterial species in the gut, greater amounts of ethanol are produced, and past a certain threshold, the ethanol metabolic product seems to reach levels where it is in a great enough concentration to equate to imbibing ethanol in the form of an alcoholic beverage. It should also be noted that this same fermentation process is used to achieve the alcohol content in said beverages, though this, of course, does not take place directly in our stomachs.
Even with a greater understanding of the microbiota, the precise nature of why these yeast populations can grow so large and lead to ongoing intoxication remains unknown. Cases are so rare that really everything we know about this disease is almost entirely anecdotal. Perhaps the patients ate an absurd amount of sourdough after taking antibiotics that would have wiped out many of the bacteria just prior to yeast colonization? Whatever oddball circumstance lead to this, the end result? Enough yeast in your gut to lead to fermentation levels that are actually sufficient enough to influence blood alcohol levels. Sounds pretty awesome if it only lasts for the three days you spend at Coachella, but week in and week out, it would probably get old pretty quickly.