Fermented foods have become very popular, thanks to claims about their nutritional properties and reported health benefits, such as improving digestion, boosting immunity, bowel regularity and even helping people lose weight.

Kombucha, sauerkraut, kefir, pickles and other fermented foods are touted as a “must-have” for a healthy gut and microbiome by almost every functional medicine and natural health expert.

You can also check out my blog, where I talk all about gut health and brain connection.

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Though these fermented foods might offer us many health perks, most people aren’t aware that they might not work for everyone. However, there is a downside to fermented foods that you may not know about. The question of how and when to eat fermented foods is a hot button issue.

Are fermented foods truly Bulletproof? The answer is more complex than it seems, thanks to a compound called histamine.

Histamines are byproducts of fermentation produced by certain bacteria and can leave some people feeling pretty messed up.

Understanding The Fermentation Process

Let’s take the latest fermented food which is popular with the health-conscious; Kombucha, which is a mix of yeast and bacteria fermented with black or green tea.

Kombucha uses a SCOBY (symbiotic colony of bacteria and yeast). Not only are good bacteria or probiotics present, bad bacteria and yeast are also present during the fermentation process.

All of the prebiotics produced during that process also feed bad bacteria and yeast. This means that fermented foods themselves may be high in bad bacteria and yeast.

In addition, the high concentration of prebiotics found in fermented foods also makes its way to your gut.

There, it feeds good bacteria, bad bacteria, and yeast alike. So if you already have an overpopulation of bad bacteria or yeast, eating fermented foods adds fuel to the fire.

This means that while it’s true that fermented foods do have potential health benefits, they may cause more harm than good by perpetuating gut infections!

5 Common side effects of fermented foods include:

1. Gas and Bloating

The most common reaction to fermented foods is a temporary increase in gas and bloating. This is the result of excess gas being produced after probiotics kill harmful gut bacteria and fungi. Although bloating after eating probiotics seems to be a good sign that the harmful bacteria are being removed from the gut, some people might experience severe bloating, which can be very painful.

Drinking too much kombucha can also lead to excess sugar and calorie intake, which may also lead to bloating and gas.

Fermenting does not remove gluten, soy, or dairy allergens.

2. Headaches and migraines

Fermented foods rich in probiotics – including yogurt, sauerkraut and kimchi – naturally contain biogenic amines produced [during fermentation].

Amines are compounds that form naturally in fermented foods that contain protein and most commonly include histamine, tyramine, and tryptamine.

Some people are sensitive to histamine and other amines and may experience headaches after eating fermented foods. Because amines stimulate the central nervous system, they can increase or decrease blood flow, which can trigger headaches and migraines.

3. Histamine intolerance

Histamine is plentiful in fermented foods. For most, our body’s specific enzymes will naturally digest them. However, some people don’t produce enough of these enzymes. This means histamine won’t be digested and will instead be absorbed into the bloodstream.

This can cause a range of intolerance symptoms. The most common are itching, headaches, runny nose (rhinitis), eye redness, fatigue, hives and digestive symptoms including diarrhoea, nausea and vomiting.

However, histamine intolerance can also cause more severe symptoms, including asthma, low blood pressure, irregular heart rate, circulatory collapse, sudden psychological changes (such as anxiety, aggressiveness, dizziness and lack of concentration) and sleep disorders.

4. Food-borne illness

While most fermented foods are safe, it’s still possible for them to get contaminated with bacteria that can cause illness.

In most cases, probiotics found in fermented milk products such as cheese, yogurt and buttermilk can effectively prevent the growth of certain bacteria, such as Staphylococcus aureus and Staphylococcal enterotoxins which can cause food poisoning. But in some cases, probiotics fail and bacteria can actually secrete toxins, so the product may be hazardous.

5. Infection from probiotics

Probiotics are generally safe for the vast majority of people. However, in rare cases, they can cause infection – especially in people who have a compromised immune system.

Susceptible patients, such as those with compromised immunity, should be advised against consuming too many probiotics.

Treatment with probiotics can cause serious infections, such as pneumonia in vulnerable people and systemic infections, including sepsis and endocarditis.

Okay, what do I do now?

If you’re new to fermented foods, make sure to start slow to help avoid symptoms. But if you’re having regular negative symptoms, even after consuming small amounts of fermented foods, it’s important to figure out the underlying cause.

If this sounds like you, it’s a good idea to pay a visit to a Holistic nutritionist for diet consultation. From there, you need to work closely with your nutritionist to manage symptoms and repair your gut, and then start slowly rebuilding your gut flora.

Here are symptoms of poor gut health. And here are gut-friendly homemade drinks to try.