A Literal "Beer Gut"

Imagine you are a police officer and suddenly the car in front of you is beginning to drive erratically. You dismiss it at first, thinking the driver was just momentarily distracted. Then he starts swerving left and right, slowing down and then speeding up. You take a closer look inside the car. Looks like a family of four. Presumably the wife in the passenger seat, two kids in the back. The kids are behaving. He's not using his phone. The driver doesn't look distracted.

After the man nearly runs the car up on the sidewalk, you flash your lights. He pulls over without incident and appears cooperative, almost happy. Carefree, in fact.

"What's the problem, officer?" His words are slurred, virtually confirming your suspicion. This guy is three sheets to the wind (incidentally, that is an old maritime phase referring to when fasteners holding the sails became loose and control of the boat was lost).

"Have you been drinking tonight, sir?"

"Nope! Just had some spaghetti and breadsticks. Hey, I like your badge. Shiny! Can I hold your gun?" He becomes giddy with laughter.

You look over at the woman in the passenger seat. "It's true, officer. He never drinks! He gets this way after having pasta sometimes. I told him not to have seconds. How about I drive instead and we just forget the whole thing?"

Sounds like a family trying to put one over on the police, but there really is a condition called "auto-brewery syndrome" or "gut fermentation syndrome". People experience this rare condition when microbes turn the belly into a brewery. 

People with the rare condition known as "auto-brewery syndrome" can turn this carbohydrate-rich plate of pasta into enough alcohol to make them feel drunk.

A woman recently diagnosed with the syndrome had her DUI charges dismissed. She was monitored for a twelve hour period, taking a breathalyzer test every few hours. Despite having no alcohol whatsoever, her blood alcohol content rose steadily throughout the day, reaching to four times the legal limit by the end of the period.

As we've mentioned in previous articles, our body is home to trillions of microbes that collectively made up our microbiome. These microbes are largely intestinal bacteria and fungi. They perform indispensable tasks for us, such as helping to produce neurotransmitters, vitamins, and immune regulators. But on very rare occasions, certain yeasts in our gut, namely Saccharomyces cerevisiae or Candida albicans, can grow out of control and start converting carbohydrates into alcohol.

People with auto-brewery syndrome quite literally have a "beer gut". The yeast in their body can produce alcohol without the person taking a sip of booze. Some people learn to adapt and live with this higher-than-average blood alcohol content, much like anyone who builds up a tolerance to alcohol by increasing hepatic (liver) metabolism. Unbeknownst to them, some people have been living with the condition for years.

People with auto-brewery syndrome actually make alcohol in their intestines where the fungi live. So feeding them hops and tapping their stomach is not going to provide you and your friends with a ready source of free beer.

It is not known why the yeast can take such a foothold in the gut of these patients. One documented case report suggests that a course of antibiotics, which wipe out a lot of "friendly" gut bacteria but don't hurt yeast, can create an environment in the intestine that favors growth of the yeast. With the bacteria depleted, there is less competition for nutrients, so the yeast can grow out of control. Some researchers have argued that overgrowth of fungi is not to blame, but rather the patient may have genetic defects that prevent the liver from metabolizing the minute, normal levels of alcohol that may ferment in the gut. These two possibilities are not mutually exclusive.

Yeast are a type of fungi that have enzymes able to convert sugars like glucose into pyruvate, ethanol (alcohol), and carbon dioxide as waste products. One organism's waste is another organism's treasure!

In addition to creating obvious hazards and embarrassing situations, auto-brewery syndrome causes bad hangovers as well. Is there any way to alleviate this problem? One report stated that a 10 week course of anti-fungal drugs and probiotics, the latter of which aim to replenish the gut with bacteria that belong there, eliminated the condition from the patient.

So if you see someone acting like a belligerent fool for no logical reason...well, most likely they're just being a jerk. But there is a small chance that they have auto-brewery syndrome and deserve your compassion rather than condemnation.

Contributed by:  Bill Sullivan
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Cordell, B., & McCarthy, J. (2013). A Case Study of Gut Fermentation Syndrome (Auto-Brewery) with Saccharomyces cerevisiae as the Causative Organism International Journal of Clinical Medicine, 04 (07), 309-312 DOI: 10.4236/ijcm.2013.47054