When I first tried homemade miso (versus the off-the-shelf kind), I had a gut-wrenching reaction similar to mild food poisoning or some sort of miso-induced food allergy.
Of course, there was a chance that I had messed up the ferment and was experiencing food poisoning… However, no one else had any issues with the miso. And it looked, smelled, and tasted good. It was definitely not food poisoning…
…My body was just reacting to a new type of fermented food.
When can fermented foods cause problems?
Fermented foods are brimming with probiotic cultures that are great for improving your gut health and general wellness. They are more likely to survive digestion than a probiotic supplement. And they’re delicious!
However, there are a few circumstances where fermented foods can cause unpleasant side effects.
Here are a few reasons why fermented foods might not be good for you:
- Certain fermented foods are not recommended for pregnant women, children under the age of 1 year, or anyone who is immunocompromised. Like raw eggs, unpasteurized cheese, and honey, certain fermented foods be unsafe.
- If you are allergic to something in fermented foods, then it’s going to cause problems. Fermenting does not remove gluten, soy, or dairy allergens.
- Fermented foods tend to be high in histamine and MSG. So if you’re sensitive to either of these, avoid eating large servings of fermented foods.
- Side effects can also occur when introducing new fermented foods to your diet.
Common side effects of fermented foods
Wondering why new fermented foods may cause side effects?
It’s because they are bringing a whole new set of probiotic friends to the party in your digestive system.
When the probiotic cultures don’t get along a fight ensues. A few of the unsavory types end up getting kicked out as the brawny newcomers assert themselves. Then slowly, over time, your digestive system will settle down as everyone finds a new equilibrium.
Some of the common side effects of fermented foods include:
- Gas and bloating
- Nausea and diarrhea
- Dizziness and racing heart
A strong reaction isn’t always a bad thing, especially if you were eating fermented foods to improve your gut health. However, if the reaction feels like an allergy or exasperates allergy symptoms, then I recommend avoiding that particular type of ferment in the future.
How to prevent side effects
A gut-wrenching reaction to a new ferment may actually be a good thing! It means that you are slowly bringing the microbiome in your gut back into a healthy balance. This is particularly true if you were eating fermented foods to recover from antibiotics.
Regardless, self-punishment is not the way to introduce new probiotic cultures. Never overdo it thinking that you’ll cure yourself quicker. There is no point in suffering if you don’t have to.
Here’s how to prevent possible side effects of fermented foods:
- Ferments that are made with an airborne culture should not cause a large reaction, as they are already in your home. This includes sourdough and ginger bug.
- Only try a small amount (1 Tbsp) of any fermented cultures that are very new to you. Personally, I reacted to miso and water kefir. However, other unique fermented cultures include heritage yogurt strains, milk kefir, kombucha, jun, and raw tempeh.
- Continue eating a tablespoon of the new probiotic food every day for a week so that your body can adjust to the new culture of bacteria and yeasts.
- After a week, feel free to try a small serving. If it doesn’t cause any digestive symptoms then you’re free to eat as much of that fermented food as you want.
Have you had a problem with a particular fermented food? Share in the Facebook group Fermenting For Everyone or in the comments below.