ALLERGIC rhinitis (AR) is a prevalent upper airway condition caused by an IgE-mediated type 1 hypersensitivity reaction to allergens such as pollen, dust mites, and animal dander. Its symptoms – nasal congestion, sneezing, watery eyes, and itching – significantly reduce quality of life and impose social and economic burdens. Recent research has highlighted the gut microbiota’s critical role in modulating immune responses, prompting investigations into probiotics as a potential treatment for AR.
Probiotics are live microorganisms that offer health benefits when consumed in adequate amounts. They influence the immune system by promoting gut barrier integrity, modulating inflammation, and fostering a balance between pro- and anti-inflammatory responses. This study explored the effects of specific probiotic strains (Lactobacillus acidophilus PBS066, Lacticaseibacillus rhamnosus LRH020, Bifidobacterium breve BB077, and Bifidobacterium longum BLG240) on AR symptoms and microbiota.
The trial revealed a significant improvement in patients’ quality of life (QoL) within the probiotic group over four, eight, and twelve weeks, as measured by the MiniRQLQ questionnaire. Notably, the improvement occurred without significant changes in inflammatory markers, such as IgE levels and eosinophil counts. This aligns with previous findings suggesting that probiotic-induced clinical benefits in AR may occur via mechanisms unrelated to these markers, such as balancing the Th1/Th2 immune response and enhancing allergen-specific IgG4 production.
Microbiota analysis showed that while alpha diversity remained unchanged, there were notable increases in beneficial genera, such as Dorea and Streptococcus, in the probiotic group. These bacteria are associated with anti-inflammatory effects and a reduced risk of allergic disease. Additionally, the Prevotella/Bacteroides ratio, a marker linked to lower allergy prevalence, improved in the probiotic group.
This study highlights the potential of probiotics as an adjunct treatment for AR, offering symptom relief and improving QoL. Further research is needed to elucidate the specific immune pathways influenced by probiotics and optimise strain selection for tailored therapies. With AR affecting millions worldwide, such insights promise to reshape its management profoundly.
Katie Wright, EMJ
Reference
Lungaro L et al. Clinical efficacy of probiotics for allergic rhinitis: results of an exploratory randomized controlled trial. Nutrients. 2024;16(23):4173.
