The Curious Case of Auto Brewery Syndrome

Sober Drunk

As we all know, alcoholic beverages are made from fruits or grains by a process called fermentation, which is a chemical reaction where yeast or bacteria react with the sugars present in such items to produce ethanol and carbon dioxide. We also know that our gut is lined by a diverse population of microorganisms to protect us from infections. Ever wondered if the organisms in our gut could ferment the carbohydrates that we eat and produce alcohol in our body?

Well, it is definitely possible.

Auto brewery syndrome, also known as gut fermentation syndrome is a rare disease characterized by endogenous alcohol fermentation performed by the gut microbiota. Although the body produces low amounts of ethanol in our body normally, in this disease high amounts of alcohol are produced that cause intoxication. Its first known case was reported in 1948, where a 5-year-old African boy’s stomach ruptured and the contents reeked of alcohol despite no history of consumption.

Four years later, in Japan, this syndrome was described as a diagnostic entity where it bears the layman term Meitei-sho, which translates to “alcohol auto intoxication syndrome”.

According to a 2021 report, less than 100 cases have been reported across the globe.

Recently in Canada, a 50-year-old woman was referred to a gastroenterology clinic after 7 presentations over the previous 2 years to emergency departments (EDs) with alcohol intoxication despite her report of no alcohol consumption.

She would present to the EDs with slurred speech, smell of alcohol in her breath and falls due to somnolence. However, she was discharged with the diagnosis of alcohol intoxication, despite her reports of no alcohol intake, corroborated by her family. During her initial ED visit, her alcohol level was elevated at 39 (normal < 2) mmol/L, with normal liver enzymes. A non-contrast computed tomography (CT) scan of her head showed no acute intracranial findings. During subsequent ED visits, upon assumption that the cause was psychological, she had 3 separate assessments by psychiatrists where she scored zero on the CAGE (Cut, Annoyed, Guilty, and Eye) screening questionnaire for alcohol use disorder. On further investigation, neurological or psychiatric cause was ruled out.

On her seventh ED visit, the patient presented with slurred speech, alcohol odor in her breath, and an elevated ethanol level of 62 mmol/L. Such high levels can be fatal and is a sign of acute alcohol intoxication. Finally, a diagnosis of auto-brewery syndrome was considered by the emergency physician, who prescribed oral fluconazole (100 mg, twice daily) in hopes of killing the fungus that is responsible for this and sent a gastroenterology referral.

In the gastroenterology clinic, she was advised a 1-month course of fluconazole and low-carbohydrate diet, following which her symptoms resolved, further supporting the diagnosis. This case highlights that it is important that every physician includes ABS in their list of differential diagnosis for alcohol intoxication.

Unfortunately, a body that produces alcohol is not as fancy as it sounds. A person suffering from ABS is unable to perform daily life activities. They are unable to drive as they never know when they’ll get disoriented and crash into something. In the above case, after each ED visit, the patient needed 1–2 weeks off from work because of persistent lethargy and somnolence. Alcohol intoxication is frowned upon socially and many don’t know that such a syndrome exists so they assume that the patient has an addiction and try to stay away from them, resulting in their isolation from the society. Such social isolation further contributes to the deterioration of their mental health. Moreover, long-term exposure to the alcohol the body makes may cause the individual to crave alcohol and begin drinking thus resulting in alcohol use disorder.

Risk Factors:

Since all of us consume carbohydrates and have guts lined by microorganisms, why doesn’t everyone have ABS? The answer lies in the composition of the gut microbiota and also the existence of risk factors that make an individual more prone to it. It has been found that ABS can occur when organisms that convert carbohydrates into ethanol increase in number as compared to normal protective gut flora. This usually occurs due to overuse of antibiotics, resulting in gut dysbiosis. The common organisms involved in ABS include Saccharomyces cerevisiae (a yeast which is also used in making alcoholic beverages) and certain species of Candida such as C.albicans, C.glabrata and C.tropicalis. Research has shown that bacteria like Klebsiella pneumoniae have also been implicated as a causative agent in ABS. Moreover, high carbohydrate diet, comorbidities like diabetes, inflammatory bowel disease, liver disease also contribute to ABS due to associated high blood sugar levels and impaired ethanol metabolism by the dysfunctional liver.

Symptoms:

Diagnosis:

Since it is a rare disease, standard diagnostic algorithms have not been established yet; however, physicians usually make a diagnosis based on history from patients and their family members, physical examination, blood ethanol and liver enzyme levels. Furthermore, a glucose challenge test should be performed when the breath and blood alcohol levels are back to zero. The clinician will give glucose orally to the patient and test their breath and blood at different intervals after taking it. If the patient has high levels of blood or breath ethanol after the test, that will confirm the diagnosis.

Management:

Lifestyle changes such as low carbohydrate intake, control of diabetes and treatment of the underlying cause usually helps in resolution of symptoms. Doctors typically prescribe oral anti-fungals and probiotics to destroy the culprit and restore the normal gut flora. Fecal microbiota transplant has also shown promising results in refractory cases.

So, the next time you meet someone who seems drunk but tells you that they haven’t consumed a drop of alcohol, don’t assume that they are malingering. Another possibility could be that they know about this syndrome and are trying to save themselves from a DUI!

References:

Image credits:

https://www.researchgate.net/publication/370072894_Understanding_Auto-Brewery_Syndrome_in_2023_A_Clinical_and_Comprehensive_Review_of_a_Rare_Medical_Condition