Kirin eyes allergy-relief foods after postbiotic eases hay fever symptoms in trial

Kirin Holdings Health Science Research Institute’s clinical study has found that its Lacticaseibacillus paracasei KW3110 may alleviate hay fever symptoms that impact the eyes and improve quality of life. The company plans to use the findings to create products for improving consumer health and alleviating allergic symptoms. 

The study involved 130 participants who consumed the lactic acid bacterium L. paracasei KW3110 or a placebo for eight weeks during high pollen periods. The results were presented at the 75th Annual Meeting of the Japanese Society of Allergology last week.

In Japan, the prevalence of hay fever is increasing, affecting 40% of the population, Kirin Holdings underscores.

Allergy impacts and workings

Kirin Holdings points out that ocular symptoms such as itchy eyes, foreign-body sensations, and watery eyes have significantly disrupted the daily life of people affected by seasonal allergies.

Japan’s Ministry of Health, Labor, and Welfare has also recognized seasonal allergies’ impacts on quality of life as being “severe,” which Kirin Holdings stresses is now a societal issue.

The company explains that allergic reactions are linked to immune cells such as Th2 cells, whose excessive reactions trigger Type 2 inflammation. These can be caused by pollen, dust mites, and house dust.

Kirin points to this mechanism as evidence of why preventing Type 2 inflammation should be considered when addressing allergic reactions.

Targeting inflammation

Hay fever is triggered by pollen, causing sneezing, runny nose, and nasal congestion. Other symptoms include allergic conjunctivitis, including itchy eyes and tearing. Kirin Holdings points out that Japanese cedar pollinosis has increased by approximately 10% over the past decade.

Kirin Holdings references previous research showing that its L. paracasei KW3110 may boost the production of cytokines, such as interleukin-12 (IL-12), more than other lactic acid bacteria. IL-12 and other cytokines suppress Type 2 inflammation by activating immune cells such as dendritic cells and macrophages.

Kirin Holdings notes an increased demand for safe products that use beneficial food-derived ingredients to alleviate allergic symptoms in Japan.An earlier clinical trial also found that L. paracasei KW3110 can alleviate nasal discomfort associated with mild to moderate hay fever. The new clinical trial further explores these lactic acid bacteria to improve quality of life.

Kirin Holdings notes an increased demand for safe products that use beneficial food-derived ingredients to alleviate allergic symptoms in Japan.

Clinical findings

The researchers carried out a randomized, double-blind, placebo-controlled trial on 130 men and women aged 20 to 65 years with nasal and ocular discomfort in early spring, who did not regularly use medications. They were classified as having mild to moderate allergic rhinitis.

Participants consumed foods containing either 50 mg of heat-killed L. paracasei KW3110 or placebo from January to March.

They self-reported nasal and ocular symptoms using the Japanese Allergic Rhinitis Standard Quality of Life Questionnaire No. 1. A physician also evaluated the severity of their allergic rhinitis symptoms.

The findings reveal that participants consuming the food containing the lactic acid bacterium had significant improvements in self-reported scores for ocular symptoms and “concern about others’ perceptions” at weeks six and eight. This coincided with a period of high pollen dispersion, notes Kirin Holdings.

Nutrition’s role against allergies

Researchers pinpoint that the nerve-gut axis helps regulate the intestinal barrier, with disruptions in this system linked to increased allergy risk.

Focusing on children’s health, researchers at the Technical University of Denmark patented a method that uses metabolites from bifidobacteria to reduce children’s risk of allergies and asthma. 

Missing bifidobacteria in US babies are linked to rising allergies, asthma, and eczema. However, a recent study found that probiotic B. infantis supplementation could help restore beneficial gut bacteria in exclusively breastfed infants, even beyond the newborn stage.

To address babies’ allergy risks, international researchers previously mapped their gut bacteria into an atlas, revealing opportunities for creating new, tailored probiotics.