Some people have six-packs and others have kegs, but it appears an unusual few actually have an entire brewery operating in their bellies.
That fact has emerged in the United States, where a woman last month successfully beat a drink-driving charge by arguing that she suffered from "auto-brewery syndrome".
The woman was arrested in Hamburg, New York state, in October 2014 after she was seen driving with a flat tyre and "weaving all over" the road, according to local police.
The 35-year-old schoolteacher was breathalysed and returned a blood alcohol reading of 0.33 - more than four times the state's legal limit of 0.08.
The woman, who has not been named, claimed to have only consumed four drinks over the six hours leading up to the test, according to CNN, which with her size and weight should have resulted in an alcohol reading of between 0.01 and 0.05.
Seeking an explanation, her defence lawyer Joseph Marusak turned to the internet and soon found one: auto-brewery syndrome.
The extremely rare condition, also known as gut fermentation syndrome, can occur when abnormally high levels of gastrointestinal yeast turns food carbohydrates into ethanol.
"She can register a blood alcohol content that would have you or I falling down drunk, but she can function," Mr Marusak told local newspaper The Buffalo News.
He said his client had so much yeast in her gut that it functioned like a "brewery", resulting in "one of the strangest cases I've ever been involved with in more than 30 years as a lawyer."
Mr Marusak hired two nurses and a professional trained in using breathalysers to monitor his client's blood alcohol levels on a day when she had not been drinking at all.
Lo and behold, she returned levels similar to those on the day she was arrested.
Mr Marusak presented those and other medical tests in court, which was persuaded by the evidence and dismissed the drink-driving charges on December 9.
Prosecutors, however, are seeking to have the charges reinstated.
In the meantime the woman has successfully treated her condition by removing yeast from her diet and taking antifungal medication.