Auto-Brewery Syndrome (ABS)

Have you ever felt drunk but swear you didn't have a single drink? Symptoms such as brain fog, mood changes, clumsiness, impaired judgement, drowsiness, dizziness, delayed reaction time, reduced inhibitions, to more significant ones such as loss of balance, confusion, slurred speech, blurred vision, nausea and vomiting, fainting or even seizures could be related to Auto-Brewery Syndrome (ABS).

The Curious Case of Auto Brewery Syndrome - The Checkup

What is Auto-Brewery Syndrome?

Auto-brewery syndrome, also known as gut fermentation syndrome is a rare medical condition in which carbohydrates are converted into alcohol through gut fermentation. An overgrowth of yeast or bacteria in the gut can be triggered by antibiotic use, a diet high in carbohydrates, and diseases such as diabetes, liver disease and inflammatory bowel diseases. There is a disruption in normal gut health that creates an environment in which alcohol-producing microbes are overgrown.

Symptoms of ABS

The symptoms of auto-brewery syndrome are the same as being 'drunk'. Things like slurred speech, loss of motor functions, brain fog, gastrointestinal issues, and dizziness can all be present. Elevated blood alcohol levels and a failed breathalyzer test can result. Some individuals have even been charged with drunk driving without ever having a drink.

Risk Factors

The presence of fermenting yeasts or certain bacteria in the gut can cause ABS. A diet high in carbohydrates is also a risk factor. Existing health conditions such as type 2 diabetes, liver cirrhosis, or bowel conditions where the bowel has been stretched allowing these organisms to sit longer are the biggest risk factors. It is a rare condition and can be found in children or adults both male and female.

Treatment

Treatment of ABS can range from antifungals to diet and probiotics. Antifungals can be prescribed after a test determines the type of bacteria or yeast that is affecting the individual. A diet lower in carbohydrates and higher in protein. Probiotics can also help balance the bacteria in the gastrointestinal tract. Antibiotics should be avoided unless necessary. After treatment, the individual could experience relapses. Chronic ABS may require fecal microbiota transplantation.

Complications

The complications are similar to those of alcohol abuse. Things such as falls and injuries, DUIs, Liver disease, and even fetal alcohol syndrome can occur. Not to mention the social implications, affect on family and friends, ability to work and function normally. It is rare, but alcohol poisoning can also be a complication and can be fatal.

Diagnosis

Testing for ABS would come after discovery of having symptoms of alcohol toxicity and having an elevated blood alcohol level but never having had a drink. Tests may include blood tests, breathalyzer, physical exam, a glucose tolerance test to observe carbohydrate response, a hydrogen breath test to identify bacteria, a stool test or even a colonoscopy.

With proper diagnosis and treatment, this rare medical condition is treatable. However, if untreated can be a very devastating disease physically and socially.

Jennifer Hoar, RN

References

"Auto-brewery syndrome." (2025) https://en.wikipedia.org/wiki/Auto-brewery_syndrome

"Auto-Brewery Syndrome; Symptoms, Causes & Treatment." (2025) https://my.clevelandclinic.org/health/diseases/auto-brewery-syndrome

Assessed and Endorsed by the MedReport Medical Review Board