Should People With IBS Avoid Fermented Foods?

Fermented foods might be trendy these days because they contain living beneficial bacteria. But eating or drinking fermented things can cause the very symptoms that go along with irritable bowel syndrome (IBS). So should people with IBS and other gut disorders avoid fermented foods and drinks?

Traditional, fermented foods that have been around for thousands of years like kimchi and sauerkraut are currently sharing the foodie spotlight. There’s kimchi pancakes and tacos. Adult kombucha beverages are trending. Yogurt doesn’t seem to be going out of style. Even fermented beet juice—beet kvass—can be found at artesanal supermarkets.

More and more people are becoming aware of the importance of having a healthy gut microbiome. Having enough good bacteria in the gut, and a diverse number of strains of friendly bacteria is critical for a healthy immune system, stable mood, efficient metabolism and every facet of our well-being.

Fermentation is basically the oldest method of food preservation. The ancient Koreans who began burying fermented cabbage in ceramic pots roughly 4,000 years ago didn’t know their colonocytes from their lactobacilli. But what they did realize is that fermentation keeps food alive and what we would call in this modern age, shelf-stable.

Eventually, science—in the 19th century—discovered that the fermentation process, specifically lacto-fermentation, produces beneficial bacteria. Lacto fermentation creates lactic acid bacteria, otherwise known as lactobacilli. (The bacteria break down the sugar in the cabbage, which produces lactic acid bacteria.)

But if you’ve ever eaten a forkful or two of sauerkraut—or sat next to somebody that has—you know all too well that it can cause gas. Yes, fermented foods contain probiotics. But fermented foods are not technically probiotics. And for people with irritable bowel syndrome (IBS), this is an important distinction to make. 

Are Fermented Foods Safe For IBS?

Before answering this question, let’s explain the difference between fermented foods and probiotics. As stated, fermented foods contain beneficial bacteria (probiotics). But not all fermented foods do not list how much bacteria and which strains of bacteria are included.

For the 10%-15% of Americans estimated to be living with IBS, one of the most common digestive disorders, this is an important distinction. That’s because every body’s gut microbiome is different. Probiotic supplements on the other hand are specifically tested to confer a health benefit.

In other words, when you pick up a jar of sauerkraut, it’s not going to mention how many of each of the four lactic acid bacteria it contains. But probiotic supplements are backed by scientific research.

Does this imply that people with IBS shouldn’t eat fermented foods and only try to repair their gut with probiotic supplements?

No, not at all.

Which Strains of Bacteria Are Good for IBS?

Luckily, lactobacillus types of bacteria (the plural is lactobacilli) is one of two main groups that is beneficial for people with IBS, according to Harvard Health Publishing.  Bifidobacterium is the other group of bacteria that is commonly used to treat IBS symptoms (gas, bloating, abdominal pain or distention, cramps, diarrhea, constipation, etc.).

Interestingly, Dr. Anthony Lembo, writing for Harvard Health, says that inactive probiotic strains can yield beneficial results for those with IBS. When we think of probiotics, we think about live, friendly microscopic critters that are gobbling up the starches we eat in order to help us digest our food and convert the food particles into usable nutrients and short-chain fatty acids that provide us with so many health benefits.

But probiotics can actually be inactive or dormant, like they’re taking a food coma nap. Actually, the inactivated Bifidobacterium bifidum MIMBb75 strain that was found to be beneficial for IBS in one study was inactivated due to heat processing.

Heat processing to make probiotics inactive, Dr. Lembo explains, is more shelf-stable and is easier to standardize, and is less likely to cause infections. So keep that in mind if you have IBS and take a probiotic supplement. 

Fermented Foods and Low FODMAP Diet

But what about eating and drinking fermented foods? Should those with IBS avoid them? After all, people with IBS most often do better eating a low-FODMAP diet. FODMAP foods are fermented carbohydrates. Those with IBS who eat a high-FODMAP diet typically experience worse digestive upsets.

That doesn’t mean, however, that fermented foods can’t be part of a low-FODMAP diet. The simple solution for consuming the beneficial bacteria in fermented foods if you have IBS is to eat small portions of it.

For example, if you have IBS and want to indulge in sauerkraut to see what all the hype is about—really, there’s nothing special about the taste of fermented salted cabbage—just eat one tablespoon. Don’t go overboard and slather your hot dog or bratwurst sausage with it. The hot dog itself will be terrible for your IBS!

Eating fermented food can actually lower the amount of FODMAPs in certain foods that would otherwise be eaten raw. However, that’s not always the case; fermenting foods can actually raise the levels of FODMAPs. This is the case with sauerkraut.

So if you’re experiencing gas after eating sauerkraut, that could be why.

But let’s say you love the taste of sauerkraut—and have IBS. Should you avoid it? That’s your call. The important thing to keep in mind is that if you have IBS, you should keep your portions of fermented foods to a minimum.

Do you have IBS? If so, what’s your experience with eating fermented foods? Join the discussion. We love your feedback.