A 40-year-old Bruges resident was caught driving under the influence in April 2022. A month later he was exposed again. Converted, he had 2.1 and 1.6 per mille of alcohol in his blood. The criminal court acquitted the man today, because medical examination showed that he suffers from the “auto-brewery syndrome”. However, the public prosecutor had requested that he be declared unfit to drive for life. But according to the judge, “the man was not aware of the condition” and there was “force majeure”. He did receive a warning: in the event of a subsequent violation, the force majeure argument no longer applies.
1. What is auto-brewery syndrome?
Someone with auto-brewery syndrome produces alcohol in their intestines. That in itself is not unusual, says Danny De Looze, gastrointestinal specialist at Ghent University Hospital and author of the book What our intestines tell us. “Everyone produces alcohol in their body every day, because we eat carbohydrates every day, such as bread, pasta and potatoes. Certain bacteria in our intestinal flora ferment the sugars in those carbohydrates and convert them into alcohol, just like when making beer or wine.”
However, for most people, this alcohol production is so minuscule that no alcohol will be detected in the blood, let alone get drunk or give a positive breath test, says De Looze. But some people have a different composition of intestinal flora, which means that they convert sugars into alcohol much faster. “We don’t know which bacteria or yeasts are more powerful. But their intestines work like a kind of brewery.”
Like someone who has looked too deeply into the glass, someone with the syndrome may feel drunk. Other symptoms such as slowed reflexes and dizziness may also occur, although these symptoms may be less visible. “If you have the syndrome and eat carbohydrates every day, you become, as it were, unconsciously an alcoholic,” says toxicologist Jan Tytgat (KU Leuven). “Habituation occurs, which means you can tolerate alcohol better, but your liver is put under just as much strain.”
2. How common is the condition?
According to both experts, the syndrome is very rare. Patients who claim they suffer from it can be tested by ‘carbohydrate loading’, says De Looze. “They have to eat carbohydrate-rich meals with, for example, lots of sandwiches. Every so often we take blood analyzes. This all happens in a controlled environment, so that we can be sure that they do not drink secretly.” Until now, doctors have been able to diagnose the syndrome in only one patient. “Sometimes someone turns out to be a hidden alcoholic after all. I remember a Dutchman whose tests were negative, but who always claimed not to drink. A while later he came back and admitted that he was actively drinking.”
3. What can you do about it?
Pretty simple: stop eating carbohydrates. The Bruges resident also limits himself to a low-carbohydrate diet these days, says his lawyer. A course of antibiotics could also provide relief. “But because we don’t know which bacteria cause the syndrome, it doesn’t work for everyone,” says De Looze. An alternative is a stool transplant, which can change the intestinal flora. “We successfully treated that one patient who we were convinced had the syndrome. But it is not yet clear whether that method works for everyone.”
4. Will the acquittal of the Bruges resident become a precedent?
According to professor of criminal and traffic law Philip Traest (UGent), this is not the case. He emphasizes that there cannot be force majeure twice and that an offender who invokes the condition will have to substantiate this, for example with a medical certificate. Police Judge Peter D’Hondt expects “a substantial increase in the syndrome”. He cannot comment on this specific case, but people often say “n’importe quoi to avoid a conviction,” he says. “There are even files in which the lawyer argues that eating eel in green food has led to a false positive test for cocaine use.”
