Lacticaseibacillus paracasei KW3110 Confirmed to Alleviate Mild to Moderate Hay Fever Symptoms

Research Findings (Overview)

A clinical trial was conducted involving 120 men and women aged from 20 to 64 with mild to moderate allergic rhinitis to evaluate the effects of L. paracasei KW3110 on nasal and ocular symptoms as well as quality of life (QOL). During the spring pollen season (January to April), participants consumed either a food containing L. paracasei KW3110 (50 mg heat-killed bacteria, equivalent to over 140 billion cells) or a placebo food (without L. paracasei KW3110) for 12 weeks. The group that consumed the L. paracasei KW3110-containing food showed improved nasal symptom scores and reduced impairment in outdoor activities compared to the placebo food group, particularly during the initial pollen dispersal period observed at week 4 of consumption (Fig. 2).

Implications

The research results indicate that L. paracasei KW3110 helps reduce nasal discomfort during the early pollen dispersal period and alleviates the decline in quality of life (QOL) associated with limitations in outdoor activities.

Future Prospects

Through continued research on L. paracasei KW3110, we aim to contribute to addressing health challenges such as hay fever by alleviating the decline in quality of life (QOL) caused by allergy symptoms.

Expert Commentary Provided by Dr Yoshitaka Okamoto, MD, PhD

According to a survey conducted by Japan’s Ministry of Health, Labour and Welfare, approximately one in two people in Japan currently suffer from some form of allergic disease, and the number of allergy sufferers continues to rise each year. Among these, allergic rhinitis affects nearly half the population. Cedar pollen allergy, in particular, is referred to as a “national disease” due to its high prevalence and severity of symptoms, posing a significant societal challenge.
Our research group has previously published findings indicating that L. paracasei KW3110 may help improve allergy symptoms in individuals with hay fever. The results of this clinical trial suggest that consuming this strain as a food may improve quality of life, particularly for individuals with mild nasal allergy symptoms. Naturally, individuals with severe symptoms should seek medical attention. However, the safety and convenience of consuming lactic acid bacteria as a food are noteworthy. Among lactic acid bacteria, L. paracasei KW3110 is readily taken up by immune cells, where it elicits a unique response that may help suppress allergic reactions. We anticipate continued research to further elucidate the distinctive functions of this specific strain.
Moving forward, we anticipate that further elucidation of its mechanisms of action, along with the accumulation of new clinical data, will lead to potential improvements not only in rhinitis symptoms such as hay fever, but also in a broader range of allergy-related conditions.

Dr Yoshitaka Okamoto, MD, PhD

Director, Chiba Rosai Hospital, Japan Organization of Occupational Health and Safety (JOHAS)
Professor Emeritus, Chiba University

Graduated from the Faculty of Medicine, Akita University in 1979. Conducted research in mucosal immunology as a research fellow at the State University of New York at Buffalo. Served as Professor of Otolaryngology at Yamanashi Medical University, Professor of Otolaryngology and Head and Neck Oncology at Chiba University Graduate School, and Vice President of Chiba University Hospital before assuming his current position in 2019. Specializes in otolaryngology, with a focus on the treatment of head and neck tumors, as well as the research and management of upper airway immunology and allergies. Served as President of the 67th Annual Meeting of the Japanese Society of Allergology. Previously conducted research on Lacticaseibacillus paracasei KW3110 and its relationship to allergic conditions.

About Lacticaseibacillus paracasei KW3110 (L. paracasei KW3110)

Lacticaseibacillus paracasei KW3110 is a strain of lactic acid bacteria originally isolated from cheese. It was identified through joint research by Kirin and Koiwai Dairy, selected from over 100 strains. This strain is expected to help regulate immune balance.

Background and Purpose

Hay fever (seasonal allergic rhinitis) is an allergic disease triggered by pollen, most commonly presenting as allergic rhinitis (sneezing, runny nose, nasal congestion) and allergic conjunctivitis (itchy eyes, tearing). The prevalence of hay fever (seasonal allergic rhinitis) exceeds 40% of the population in Japan. Notably, the prevalence of cedar pollen allergy has increased by approximately 10% over the past decade, and further increases in hay fever prevalence are anticipated, presenting a significant societal challenge. There is a growing demand for the development of products that utilize beneficial components found in food and beverages to safely alleviate allergy symptoms, with minimal concerns such as drowsiness. Through previous research, Kirin has demonstrated that L. paracasei KW3110 activates macrophages, a type of innate immune cell, and enhances Th1 cytokine production, in addition to its effects in relieving allergy symptoms. This study aims to develop a product containing L. paracasei KW3110 to alleviate allergy symptoms such as hay fever (seasonal allergic rhinitis), with the goal of improving the quality of life (QOL) diminished by rhinitis symptoms.

Research Method

The study was designed as a randomized, double-blind, placebo-controlled trial. A total of 120 participants (men and women aged 20 to 64 years) who experienced nasal and ocular discomfort in early spring and did not regularly use medications for allergic rhinitis symptom relief were enrolled. Participants consumed either a food containing Lacticaseibacillus paracasei KW3110 (50 mg heat-killed bacteria, equivalent to at least 140 billion cells) or a placebo food for 12 weeks (January to April). Self-reported nasal and ocular symptoms were assessed using the Japanese Standard QOL Questionnaire for Allergic Rhinitis, and the severity of allergic rhinitis symptoms was evaluated based on an otorhinolaryngologist diagnosis.

Results

Compared to the placebo, consumption of food containing L. paracasei KW3110 significantly improved subjective symptom scores (“nasal symptoms” and “impairment in outdoor activities”) and severity classification scores (“sneezing attacks or rhinorrhea” and “severity”) during the early pollen season at week 4 of intake (Figs. 1 and 2).

Research Findings

This study suggests that L. paracasei KW3110 reduces nasal discomfort during the early pollen dispersal period and mitigates the decline in quality of life (QOL) associated with difficulties in outdoor activities.