Allergies occur when the immune system overreacts to a typically harmless substance, such as pollen, dust, or certain foods. Probiotics, especially certain strains, can help regulate immune responses and alleviate allergic symptoms by influencing the balance of gut bacteria and modulating inflammation.

Read before: Unlocking the World of Prebiotics, Probiotics, and Postbiotics: The Complete Guide

1. Regulating the Immune System

Probiotics play a significant role in modulating the immune system, which is critical in managing allergies. In allergies, the immune system tends to skew towards a Th2-dominant response, leading to an overproduction of antibodies like IgE, which trigger allergic reactions. Probiotics, especially strains like Lactobacillus rhamnosus and Bifidobacterium longum, can shift the immune response towards a Th1-dominant response, which reduces the production of IgE and thus alleviates allergic symptoms.

Lactobacillus rhamnosus, in particular, has been found to boost the production of regulatory T cells (Tregs), which are essential for maintaining immune tolerance. These Tregs help control and reduce allergic inflammation by suppressing the overactive immune responses that are typical in allergic individuals. This makes probiotics effective in managing both respiratory allergies like hay fever and skin allergies like eczema.

2. Improving Gut Health to Reduce Allergic Inflammation

The gut microbiome is closely linked to immune function, and an imbalanced gut microbiome, also known as dysbiosis, is often associated with increased inflammation and a higher risk of developing allergies. Probiotics such as Lactobacillus casei and Bifidobacterium bifidum help restore balance to the gut flora by promoting the growth of beneficial bacteria and reducing harmful bacteria.

A healthier gut microbiome reduces systemic inflammation, which in turn lowers the overall burden on the immune system, helping to reduce the likelihood and severity of allergic reactions. For individuals with food allergies, maintaining a balanced gut microbiome can be especially beneficial in managing symptoms.

3. Strengthening the Gut Barrier

A key factor in allergies, particularly food allergies, is the integrity of the gut barrier. When the gut barrier is compromised (a condition often referred to as “leaky gut”), allergens can pass through the gut lining into the bloodstream, triggering an immune response. Probiotics such as Bifidobacterium lactis and Lactobacillus reuteri have been shown to strengthen the gut barrier by enhancing the production of mucin, a protein that forms a protective layer over the gut lining. This helps prevent allergens from entering the bloodstream and causing allergic reactions.

4. Reducing Eczema and Atopic Dermatitis

Atopic dermatitis, also known as eczema, is an allergic condition often linked to an overactive immune response and dysbiosis in the gut. Probiotics, particularly Lactobacillus rhamnosus and Bifidobacterium lactis, have been found to reduce the severity and incidence of eczema, especially in children. Studies show that children who are given these probiotics early in life have a lower risk of developing eczema.

These probiotics help by reducing systemic inflammation, improving immune tolerance, and enhancing skin barrier function. In some cases, probiotic supplementation has been shown to improve eczema symptoms within a few weeks, reducing itchiness, redness, and swelling.

5. Alleviating Respiratory Allergies (Hay Fever)

Probiotics can also be effective in managing respiratory allergies, such as allergic rhinitis (hay fever). Strains like Lactobacillus paracasei and Bifidobacterium longum have been shown to reduce the severity of symptoms like sneezing, nasal congestion, and itching. These probiotics work by reducing the body’s production of pro-inflammatory molecules such as histamines, which are responsible for many allergic symptoms.

In addition, Saccharomyces boulardii, a yeast-based probiotic, can improve the immune system’s ability to distinguish between harmful and harmless substances, reducing the likelihood of allergic reactions to environmental allergens like pollen and pet dander.

6. Preventing Allergy Development in Children

One of the most exciting areas of probiotic research involves their potential to prevent the development of allergies in children. Several studies have shown that giving probiotics to pregnant women and newborns can reduce the likelihood of the child developing allergic conditions like eczema, asthma, and food allergies.

Lactobacillus rhamnosus is particularly well-studied in this regard. When taken during pregnancy and early childhood, this strain appears to promote immune tolerance in children, reducing their risk of developing allergies later in life. It is believed that the early colonization of the infant gut with beneficial bacteria helps train the immune system to respond appropriately to potential allergens.

7. Producing Anti-inflammatory Compounds

Probiotics produce a range of anti-inflammatory compounds, such as short-chain fatty acids (SCFAs), which include butyrate, acetate, and propionate. SCFAs have been shown to reduce inflammation by modulating immune cell activity and promoting the production of anti-inflammatory molecules like interleukin-10 (IL-10). These compounds help keep allergic reactions in check by reducing the production of pro-inflammatory cytokines, which are responsible for the swelling, redness, and discomfort associated with allergies.

Probiotic Strains Beneficial for Allergies

  • Lactobacillus rhamnosus: Reduces IgE levels, supports Treg cell development, and helps prevent eczema in children.
  • Bifidobacterium longum: Alleviates allergic rhinitis symptoms and strengthens the gut barrier.
  • Lactobacillus casei: Helps improve gut health and reduce allergic inflammation.
  • Bifidobacterium lactis: Supports immune function and skin health, particularly in individuals with eczema.
  • Saccharomyces boulardii: Enhances immune tolerance and reduces respiratory allergy symptoms.

Other Considerations for Managing Allergies with Probiotics

  • Diet: A diet rich in prebiotics (e.g., fiber from fruits and vegetables) can enhance the effects of probiotics by providing fuel for beneficial bacteria.
  • Supplements: Regular intake of probiotic supplements, particularly during allergy season, can help maintain a healthy gut and support immune balance.
  • Consistency: Probiotic supplementation needs to be consistent and sustained over time to have a meaningful impact on allergies, especially for those with chronic allergic conditions.