Amazing Fermentation and Allergy Link

In a previous post on the amazing fermentation and allergy link, I covered the broad basics. How, generally speaking, does the immune system work? Can fermented foods have a positive effect on the life impacting effects of food allergies? Check out my post to get caught up! However, the topic still has a little room for expansion. This post will be covering specific research on individual allergy categories and what the results show.

Specific Allergy Pathway Research

Researcher with mask on putting blue liquid into test tubes that are in container on table with other research equipment.

We saw in the previously mentioned post that there are many different pathways to travel in addressing allergies and the immune system. Covering a broad range of those is not in the scope of this post. However, I will be talking about two areas of immune system research that have garnered significant attention. Those are regulatory T cells and short-chain-fatty-acids, also known as SCFA.

Regulatory T Cell Allergy Link

Let’s dive into the world of regulatory T cells. Just as a review, regulatory T cells (Tregs) regulate/suppress the immune response towards self as well as anything from outside the body. Research on mice looked at how Tregs influence food allergies. Two groups of mice were studied; mice with no microorganisms, or mice given antibiotics. Both of those groups have a reduction in Tregs and a susceptibility to developing food allergies. On the other hand, mice given clostridia (non-virulent strains) showed an increase in Tregs and a decrease in food allergies. This was still the case when mice were given a gut bacteria profile found in humans.

SCFA/Butyrate Allergy Link

This research has shown that short-chain-fatty-acids (SCFA) have a strong, positive effect on the immune system. SCFA are so important that they are considered one of the main connections between the diet, gut, and allergies. SCFA are predominantly known as acetate, propionate, butyrate, and valerate. Butyrate specifically is a main end product of fermented foods in the intestine. The significance of butyrate on the intestine and especially the colon, is extensive. However, butyrate has great effects outside of the intestines. In fact, as well as helping with intestinal function, butyrate has been shown to help with:

Inflammation and oxidative stress
Cell growth and differentiation
Iron absorption
Immune regulation
Intestinal motility and visceral perception/pain

In addition, I will list just a handful of conditions that butyrate can help with, and often a deficiency in butyrate accompanies these ailments.

Irritable Bowl Syndrome
Diarrhea from various causes
Cystic Fibrosis
Mucosal Atrophy from various causes
Prevention of colorectal cancer
Intestinal polyposis
Allergic colitis

Specific Allergy Ailments and the Fermentation Link

Let’s move on from pathway research. The amazing fermentation and allergy link can be seen when looking at either specific food allergies, or system ailments that are associated with food allergens.

Dairy Allery and Fermentation Link

White metal milk pail sitting on hay in front of wooden background with glass of milk sitting beside it.

Children with cow milk allergy saw a reduction in allergic response and symptoms by ingesting cows milk that had been pre-broken down as well as inoculated with a beneficial bacteria.

Another research article discussed a study involving people with lactose intolerance. Half of the group were given milk while the other half were given kefir, which is fermented milk. Everyone given regular milk had the normal intestinal pain and diarrhea, however, the group given kefir experienced none of their regular symptoms when consuming the kefir.

Asthma/Respiratory Allergy and Fermentation Link

Asthma inhaler and spacer sitting on wooden table with more equipment in background.

Research on the area of asthma discusses theories as to why fermented foods help in the case of asthma and respiratory allergies. One thing to consider is that 70% of the body’s immune system is located in the gut. Therefore, even if something beneficial isn’t directly entering the airways, the immune support occurring from fermented foods can still help through immunomodulation; influencing the immune system as a whole.

Also discussed is the discovery of the “gut-lung axis,” similar in thought to the “gut-brain axis.” With the gut-lung axis, the similarity lies in both gut and lung organ cells deriving from the foregut and following a similar maturation (growth) pathway. The end results include similar physical characteristics of both gut and lung cells. Simply put, they start in the same place and end up looking/functioning similarly. The connecting pathway is hypothesized to travel from the gut to the lungs via the lymphatic system and/or the cardiovascular system.

Many studies have been done, both on animals and human trials, to see how effective fermented foods are in relieving or preventing allergic symptoms. The animal trials almost always showed improvement of some kind. Human trials are more scarce and less definitive. However, the majority did show some improvement, even if it was just participants reporting a decrease in symptoms. In summary, here is a list of ways that fermented foods can assist the airway allergenic response:

For airways, fermented foods can:
- Reduce smooth muscle hyperreactivity
- Reduce allergen permeability via decreasing space between epithelial cells
- Reduce goblet cell reproduction and mucus production
- Reduce inflammatory cells (lymphocytes, eosinophils, neutrophils) in lung fluid (BALF)
- Reduce airway remodeling

Eczema/Skin Allergies and Fermentation Link

Did you know that the skin, also called the integumentary system, is your body’s biggest organ? The skin can tell us a lot about how our body is doing on the inside. Let’s look at research on skin, allergies, and yes, the gut connection.

You’re probably tired of hearing this, but did you know that research has also found a connection between the gut and skin called the…you guessed it…”gut-skin axis.” It is amazing! Did you know, for instance, that the same microbes found in the gut can also be detected on the skin?! On the flip side, a compromise in the skin can lead to a compromise in the intestinal lining. One way the cycle keeps continuing is represent in this graphic on gut imbalance:

Graphic showing gut imbalance cause and effect circle.

Another way to look at the big picture of skin issues is to observe how the skin barrier works. One, it keeps things out. Two, it keeps things in. A very simplified version, I know. But it helps us realize that when there is some sort of unbalance with the skin, both these end results are ineffective. Thus, beneficial hydration is lost, and environmental irritants can come in.

Skin Allergy Research

Now down to some research on the, yes, amazing fermentation and allergy link! This study took a sample of healthy adults and those with atopic dermatitis (a.k.a. eczema). The research observed how healthy and affected individuals did with ingesting kefir (fermented dairy milk) for eight weeks. This also included a control group (no kefir). The results were a positive change in healthy and afflicted individuals alike. Skin hydration improved, as well as the skins ability to retain moisture. In addition, the study actually applied a skin irritant to healthy individuals and noted that those ingesting kefir had a improved rating for skin health compared to the control group. Overall, for those in the study with atopic dermatitis consuming kefir, their severity of dermatitis decreased from severe to mild.

It is important to note that the article did discuss other research in this area of study. There has not been a consistent outcome for most studies. However, the parameters being used (e.g. type of bacteria, amount ingested, duration) differed widely. In addition, redness did not necessarily decrease with those in the dermatitis group. However, redness can be something present in acute and chronic conditions. Eight weeks just might not have been long enough to see a decrease in that area.

Summary

Even though that was a lot of information, what we discussed in this post is just the tip of the iceberg when researching the amazing fermentation and allergy link. And it truly is amazing that simple diet changes can have this big of an impact! Check out some of my other posts on the topic of fermentation benefits, the science behind it and even it’s history!