It is possible for a person to become intoxicated without consuming any alcoholic beverages due to a rare medical phenomenon. This condition causes the body to produce intoxicating amounts of ethanol internally through biological processes within the digestive tract. Affected individuals exhibit all the physical and mental signs of drunkenness, including elevated blood alcohol levels, despite having consumed no alcohol. This unintentional intoxication can lead to misdiagnoses and significant distress. Understanding the underlying cause is the first step toward effective diagnosis and management.
The Primary Condition: Auto-Brewery Syndrome
The condition responsible for this internal intoxication is known as Auto-Brewery Syndrome (ABS), or gut fermentation syndrome. ABS is a medical state where specific microorganisms within the gastrointestinal system ferment ingested carbohydrates into ethanol. While the body naturally produces minuscule amounts of alcohol as a byproduct of digestion, ABS involves an overgrowth of these fermenting microbes. This microbial overpopulation generates ethanol faster than the liver can process it, causing blood alcohol content to rise to intoxicating levels. Although ABS is considered rare, experts believe it is significantly underdiagnosed due to its unusual presentation.
How the Body Produces Internal Ethanol
The production of internal ethanol is a direct result of an imbalance in the gut microbiome, a state known as dysbiosis. In ABS, ethanol-producing organisms proliferate abnormally. The primary culprits are yeasts, particularly Saccharomyces cerevisiae (the same species used to brew beer), and various Candida species. Certain types of bacteria, including Klebsiella pneumoniae, have also been implicated.
The Fermentation Process
These organisms metabolize carbohydrates through fermentation. When a person with ABS consumes starches or sugars, the gut microbes break down these complex molecules into simple sugars. The yeast or bacteria then metabolize these sugars into pyruvate. Pyruvate is converted into acetaldehyde and finally into ethanol, which is then absorbed into the bloodstream through the small intestine. Factors that can trigger this microbial overgrowth include prolonged antibiotic use, which disrupts normal gut flora, and underlying conditions like diabetes or gastrointestinal motility issues.
Identifying Symptoms and Medical Diagnosis
The symptoms experienced by individuals with ABS are indistinguishable from those of conventional alcohol intoxication. These include slurred speech, a staggering gait, dizziness, confusion, and lack of coordination. Other common complaints are chronic fatigue, irritable bowel symptoms, and a recurring “hangover” feeling. Because the symptoms appear without alcohol consumption, patients are often mistakenly accused of secret drinking or misdiagnosed with neurological or psychiatric conditions.
Diagnostic Testing
A medical diagnosis requires specialized testing to confirm the internal origin of the ethanol. Initial screening involves a breathalyzer test or blood alcohol content (BAC) measurement during an episode of apparent intoxication. The definitive diagnostic tool is the carbohydrate challenge test, performed in a controlled, fasting environment. The patient is administered a standardized dose of a simple carbohydrate, and their BAC is monitored over several hours. A significant rise in BAC confirms that gut microbes are actively fermenting the sugar. Further analysis may involve culturing stool or gastrointestinal samples to identify the specific fermenting species responsible.
Treatment and Management of the Condition
Treatment for Auto-Brewery Syndrome focuses on two main strategies: eliminating the overgrowing microorganisms and removing their food source. Pharmacological intervention typically involves antifungal medications, such as nystatin or fluconazole, to eradicate the excessive yeast populations. If the cause is a specific bacterial species, targeted antibiotics may be prescribed. The specific drug choice is guided by sensitivity testing performed on the organisms identified in culture samples.
Simultaneously, strict dietary modification is implemented to starve the ethanol-producing microbes. Patients are placed on a very low-carbohydrate, high-protein diet, which severely limits the sugars available for fermentation. Following the initial treatment phase, long-term management often includes the use of probiotic supplements. Probiotics introduce beneficial bacteria to the gut, helping to restore a healthy microbial balance and prevent relapse. This comprehensive approach is necessary to manage the disorder and allow the patient to return to a life free from unpredictable intoxication.