The source of hay fever allergies has been discovered in an unexpected location.

Overview

Experiencing symptoms like runny nose, swollen nasal passages, sinus headaches, itchy, puffy eyes, and sneezing indicates the onset of hay fever season.

While hay fever is commonly associated with childhood, individuals of any age can suffer from their first hay fever attack. The occurrence of hay fever in older adults is steadily increasing each year.

Many individuals affected by hay fever resort to decongestants and antihistamines in search of relief. However, these medications often provide minimal relief while causing side effects like dizziness, drowsiness, blurred vision, dry mouth, nausea, vomiting, and restlessness.

This alternative is related to the bacteria present in the intestines – the gut microbiota.

About three-quarters of our immune system is housed within the microbiota. Immune cells across the body receive signals and communicate constantly with the gut bacteria.

Given that hay fever is an autoimmune issue where the immune system attacks harmless substances like dust and pollen, it is logical to consider a connection with the colon.

The combination of different bacterial strains in our colon can influence how our immune system reacts to challenges. An imbalance in the colon, with an excess of 'bad' microbial varieties and insufficient 'good' ones, can lead to allergies and various other health issues.

Testing the Theory

To investigate the impact of gut bacteria on hay fever, researchers at the University of Florida enlisted 173 healthy men and women with mild to moderate seasonal allergic rhinitis (inflammation of the nasal membrane), with an average age of 27.

Participants were randomly divided to receive either a placebo or two daily supplements containing a total of three billion colony-forming units of three bacterial strains – Lactobacillus gasseri (formerly known as L. acidophilus), Bifidobacterium bifidum, and Bifidobacterium longum. The study spanned eight weeks.

These strains were specifically selected based on previous studies showing their efficacy in enhancing immunity.

The research was conducted during the allergy season, and participants were instructed to avoid consuming bacteria-containing fermented foods during the study to prevent skewing the results.

The outcomes were detailed in the American Journal of Clinical Nutrition.

Benefits of Probiotics for Hay Fever

Individuals taking probiotics reported reduced allergy-related symptoms, less disruption to their daily activities, decreased constipation issues, and enhanced quality of life compared to the placebo group.

It's important to note that participants were unaware of whether they were consuming the placebo or the probiotic.

An analysis of stool samples from participants in the probiotics group revealed a shift in the overall intestinal microorganism profile towards bacteria types beneficial for the immune system.

Although the exact mechanism is still under investigation, it is believed that probiotic strains function by increasing the population of regulatory T cells (T-regs).

A deficiency of T-regs can lead to an overly aggressive immune response, making individuals more susceptible not only to allergies but also to autoimmune and inflammatory bowel diseases. Conversely, an abundance of T-regs can mitigate inflammatory responses.

Specific bacterial species can attract these T-regs to the gut, while molecules produced by these bacterial strains, like short-chain fatty acids, aid in accumulating T-regs in the intestine to enhance tolerance to hay fever symptoms.

Enhancing Gut Immunity

Renowned researcher in immunology and microbiology, Kenya Honda, M.D., Ph.D., asserts that individual microbiota has deteriorated due to the use of antibiotics and low-quality food, rendering the host more predisposed to autoimmune conditions and allergies.

If antibiotics are necessary, it is advisable to follow up with a probiotic regimen to replenish the gut with beneficial bacteria.

Your gut health can also benefit from a diet low in refined and processed foods and rich in fruits, vegetables, and whole grains. These foods contain dietary fibers (prebiotics) that nourish friendly gut bacteria.

Another method to boost beneficial bacteria is by consuming fermented foods, which harbor a diverse array of microorganisms. Examples include unpasteurized yogurt, cultured forms of sour cream, butter, and cream cheese. Kefir, a probiotic dairy beverage rich in microbes per serving, is available in both dairy and nondairy forms.

Vegetable-based probiotics include fermented sauerkraut, kimchi, and pickles. It's essential to select products with live cultures, easily found in health food stores. Pasteurized sauerkraut lacks live microorganisms.

Of course, probiotics are also accessible in supplement form.

1. http://ajcn.nutrition.org/content/105/3/758.full