The uncommon intestinal disorder called auto-brewery syndrome (ABS), or gut fermentation syndrome, leads to the production of ethanol in the body through the internal fermentation of carbohydrates by microorganisms. Those with preexisting intestinal problems are at a higher risk of experiencing it; these individuals frequently mention consuming a diet rich in sugar and carbohydrates and display various indications and effects of alcohol intoxication despite denying alcohol consumption.

Symptoms and diagnosis of ABS

A systematic review identified several common signs observed in patients with the condition. These signs include slurred speech, a fruity breath odor, walking difficulties, episodes of depression, seizures, vomiting, feeling intoxicated, and disorientation.

The comprehensive evaluation of the patient’s condition involves a thorough assessment of the patient’s medical history, which includes details about past illnesses, family medical history, and any previous surgeries or treatments. In addition to a detailed physical examination, the evaluation also entails conducting various laboratory tests to assess blood chemistry, organ function, and potential infectious diseases. Stool culture and samples are collected to check for any abnormalities or infections in the digestive system.

Furthermore, a carbohydrate challenge test is administered to assess the body’s ability to process sugars. Endoscopy with biopsies for culture is also performed to obtain tissue samples and analyze them for any signs of infection or disease. Further, gathering the patient’s history involves obtaining information about alcohol consumption, including the frequency and quantity of alcohol intake. The usage of antibiotics and any unexplained episodes of drunkenness are also important factors to consider during the evaluation process. These details help in providing a comprehensive picture of the patient’s health and aid in determining an accurate diagnosis and treatment plan.

Gastrointestinal secretions and tissue samples for bacterial and fungal testing can be collected using procedures known as upper and lower gastrointestinal tract endoscopies. Following the collection of these samples, sensitivity tests for antifungal and antibiotic treatments can be conducted on the identified fungi and bacteria. In cases where the carbohydrate challenge test yields a positive result, a causative microorganism has been successfully grown in culture, and after ruling out all other potential explanations for the symptoms, a diagnosis of ABS (presumably referring to a specific medical condition) can be confirmed.

Causes and risk factors

This condition is believed to be caused by the fermentation of yeasts, specifically Saccharomyces cerevisiae (pictured below), S. boulardii, and other strains of Candida, including C. glabrata, C. albicans, C. kefyr, and C. parapsilosis. There has been at least one instance involving bacteria such as Klebsiella pneumonia and Enterococcus faecalis reported as well.

ABS are more prevalent in individuals with certain medical conditions that either increase the body’s production of ethanol, such as diabetes, obesity, short bowel syndrome, and Crohn’s disease, or decrease the body’s production of ethanol, such as those undergoing long-term antibiotic treatment, individuals with liver failure, and people with genetic deficiencies of liver enzymes.

Research examining individuals with and without irritable bowel syndrome (IBS) indicates that patients with IBS are more prone to experiencing food sensitivities and exhibit poorer overall health, often presenting symptoms such as diarrhea. Moreover, individuals with IBS tend to have fewer bowel movements, experience a lower quality of sleep, and have a higher prevalence of non-food allergies.

Treatment and management

The initial management of the patient should primarily involve addressing the acute symptoms of alcohol poisoning. The specific choice of drug therapy should be based on the microorganism causing the infection. In most cases, patients will require treatment with one or more azole antifungals or polyenes. In rare instances or in the presence of resistant bacteria, an antibiotic or echinocandin may be necessary for effective treatment.

In the treatment of auto-brewery syndrome, it is important to modify one’s diet to be high in protein and low in carbohydrates. This dietary adjustment is crucial in alleviating symptoms associated with the condition. Auto-brewery syndrome occurs when the fermentation of sugars in the body produces alcohol, leading to elevated levels of alcohol in the genitourinary and gastrointestinal tracts. By removing both simple and complex sugars from the diet, the amount of alcohol produced in the body can be significantly reduced, thereby helping to manage the symptoms of the condition.

There have been multiple instances documented in the literature where cases were successfully resolved without the need for medication therapy simply by adhering to dietary recommendations. While the effectiveness of probiotics such as Lactobacillus in treating this syndrome has not been thoroughly investigated, they have been utilized in specific situations.

Case studies

In 2019, there was a reported a case of a 45-year-old male Italian-American with a body mass index (BMI) of 35 who was suffering from hypertension, hyperlipidemia, and type 2 diabetes mellitus. After a nasal septal surgery in August 2015, he received antibiotics and steroids as treatment. He had spent the last twenty years without drinking.

In October 2015, two months into taking the antibiotics, he began experiencing frequent seizures and appeared intoxicated. Both the patient and his spouse stressed that he did not consume alcohol. His wife also observed that he had glazed eyes, unclear speech, and emitted an odor resembling alcohol from his breath. He was experiencing periods of incomprehensible speech, frequent falls, and episodes of impaired coordination.

After a year from the first symptoms appeared, the patient had dental surgery and was given amoxicillin/clavulanic acid, which made his symptoms worse and seemed like alcohol intoxication. Even though he didn’t consume alcohol, his blood alcohol levels rose, resulting in repeated misdiagnoses and insufficient treatment. Finally, a monitored glucose challenge test showed varying ethanol levels, confirming the presence of auto-brewery syndrome.

His diagnosis of auto-brewery syndrome occurred about 18 months after he first experienced symptoms. Initially, he followed a low-carb, high-protein diet. Additionally, he was given a pure Lactobacillus probiotic and took a three-week course of oral fluconazole at a dosage of 100 mg. Subsequently, he continued to take multiple doses of fluconazole throughout his treatment. From 2015, he has missed nearly 725 hours of work due to illness and disability. However, his outcome is positive as he has resumed work and is living a normal life while being cautious with antibiotics and avoiding all types of yeast exposure.

There was a report of a previously healthy 46-year-old man sought help for auto-brewery syndrome after experiencing significant mental changes and depression following antibiotic therapy for a thumb injury in 2019. Despite abstaining from alcohol, he showed elevated blood alcohol levels and symptoms of intoxication. Initial treatment with fluconazole and nystatin led to temporary improvement, but symptoms returned.

After further testing, it was found that he had Candida species in his gut. He received treatment with itraconazole followed by micafungin. After the treatment, no fungal growth was observed, and his condition improved when probiotics were introduced along with a carbohydrate-free diet. Reintroducing carbohydrates gradually did not lead to a relapse, and he remains without symptoms 1.5 years later. He has resumed a normal lifestyle while monitoring his breath alcohol levels. This case emphasizes how challenging it can be to diagnose and treat ABS and stresses the importance of comprehensive, ongoing management.

Research and potential future paths

It has been widely noted that there have been many instances of ABS in recent years, but additional research is required to gain a complete understanding of the mechanism, diagnosis, and proper treatment. Recently, there has been a suggestion that ABS might be a medical condition that is not diagnosed as frequently as it occurs, despite being rarely reported. To determine the true frequency of ABS, establish consistent diagnostic criteria, and explore the most effective treatment approach, further investigation is necessary. The further advancement of microbiome research will allow us to comprehend the complex connections between antibiotics, gut microorganisms, and the development of ABS.

In conclusion

Auto-brewery syndrome (ABS) is a rare yet significant condition wherein the body internally produces ethanol, resulting in symptoms resembling intoxication. Diagnosis entails a comprehensive assessment, including a review of medical history, laboratory examinations, and endoscopy. Successful treatment often involves a combination of antifungal or antibiotic medications and dietary modifications. Research indicates that ABS may be under-detected, necessitating further research to establish standardized diagnostic criteria and optimal therapies. Progress in microbiome research will play a crucial role in comprehending and addressing this intricate syndrome.