Mark Mongiardo can get drunk really easily — and it’s not because he’s a lightweight.

In fact, the 43-year-old dad gave up alcohol entirely in 2018, but he can still get buzzed, tipsy and even fully inebriated without a sip of booze.

And while that might seem like it makes for a cheap night out on the town, Mongiardo actually suffers from an extremely rare health condition that’s led to some real difficulties — including two DWI charges.

Mongiardo has auto-brewery syndrome (ABS), a rare but serious condition where people get drunk even when they haven’t had alcohol. There are fewer than 100 documented cases of the condition.

It happens when yeast — which lives in the gut naturally — overgrows. That yeast then ferments the sugar and carbs a person eats, essentially turning the bread or cake into alcohol inside their stomach.

Mongiardo struggled with symptoms for ages without knowing what was causing them — and without even realizing he was basically drunk.

“Over the years before the diagnosis, I thought that I was fatigued from long days of teaching and coaching,” Mongiardo, a former high school athletic director who lives in Florida, told The Post. “[I] wasn’t aware that I may have been acting or showing signs and symptoms of someone intoxicated.”

While Mongiardo would sometimes experience milder symptoms like brain fog or delayed reaction time, other flare-ups would be much more intense and closely resemble drunkenness as his blood-alcohol content (BAC) inexplicably rose.

He would have “slurred speech, loss of coordination, confusion and even dangerously high blood alcohol levels” that would last up to two days.

Despite only partaking in a couple of drinks at social events and never during the workweek, ABS plagued him throughout his educational career, with colleagues taking notice of the effects.

“There had been many instances where individuals complained that they smelled alcohol on me when I had not been drinking,” he said.

Though his condition was still a mystery, he knew food was the most likely culprit.

“I would often notice signs appearing after consuming foods high in carbohydrates or sugar,” Mongiardo explained. “There were also times when it wasn’t just obvious ‘sugary’ foods. Even meals that seemed relatively normal could trigger symptoms.”

Other triggers like stress, lack of sleep, overall health, and even the timing and quantity of the food he ate would also result in more severe signs.

“It’s very difficult to be awake or eat anything [during a flare-up] with the extreme feelings of nausea, so generally I’m bedridden.”

Mark Mongiardo

The condition was so bad that it cost him his job — and led to two DWI charges in six months in New York State, one of which came a year after he stopped drinking.

Still dumbfounded, he and his family searched for answers — and came upon Dr. Prasanna Wickremesinghe, a gastroenterologist at Richmond University Medical Center on Staten Island who is one of the leading researchers of the condition.

He performed a glucose challenge test typically used to screen for gestational diabetes in pregnant women. After consuming a sugary drink, Mongiardo took timed blood alcohol tests over four hours.

“Within 30 minutes, my BAC was 0.09 and elevated to 0.14 during the test,” Mongiardo said.

He was officially diagnosed with ABS and started hysterically crying because he finally had an answer.

His isn’t the first case of this syndrome, which hasbeen described in medical literature since the 1940s. A 50-year-old Canadian woman was also diagnosed in 2024.

Those who have diabetes, liver disease, abnormal contractions in their intestines, inflammatory bowel disease or even healthy people on antibiotics are at greater risk for the condition.

Because food often sets off episodes, Mongiardo follows an individualized nutritional protocol that required following various diets for certain periods to determine which foods caused a reaction.

He started with the keto diet for two weeks, followed by introducing low FODMAP vegetables for another two to four weeks, with the eventual goal to reach a Paleo-type diet with no carbs, sugar and, of course, alcohol.

Mongiardo lives with constant vigilance to avoid the unpredictable nature of his condition, carrying multiple breathalyzers and checking his blood alcohol levels before driving.

“The best management of the symptoms is to rest or sleep as much as I can until my BAC is back to zero,” he added. “It’s very difficult to be awake or eat anything with the extreme feelings of nausea, so generally I’m bedridden.”

While he no longer has near-daily flare-ups, Mongiardo still experiences symptoms multiple times a week, since he does have some unintended slip-ups.

Once, for example, he took a sip from his son’s water bottle. He soon felt dizzy, nauseous and fatigued — telltale signs that he was intoxicated. After a test, he learned he had a blood alcohol content of 0.09, a level that’s considered legally drunk in many states.

It turned out that crumbs from the cookie his son had been eating had clung to the water bottle, making their way into Mongiardo’s system.

But working with a gastroenterologist, an infectious diseases specialist and a nutritionist, Mongiardo has been able to figure out which meals or stressors would set off episodes, which became less frequent and more predictable.

He still needs to live with constant vigilance, alternating various medications and supplements timed along with food to avoid another incident.

But his outlook is hopeful now that he has a plan of attack, and he says answers about his mystery condition brought back a sense of control to his life.

“In the beginning, this felt confusing and honestly pretty isolating and overwhelming because you’re dealing with something most people don’t understand,” he explained. “Mentally, that uncertainty was the hardest part.”

He also understands that despite a treatment to manage symptoms, the journey isn’t over.

“If anything, it’s made me more disciplined, more resilient, and more aware of my health,” he said. “I feel like I’m moving forward instead of just trying to keep up.”