Effect of Probiotics on Allergic Rhinitis: A Randomized, Controlled, Clinical Trial

Abstract

Background: Allergic rhinitis (AR) is one of the most common diseases in the world and affects about 10-50% of the general population. Probiotics are live microorganisms that help the normal state of the intestine, and if prescribed correctly, they can stimulate the mucosal immune system to prevent inflammatory symptoms of allergy and atopy. The present study aims to investigate the role of probiotics in the treatment of AR when added to standard therapy as adjuvant agents. Materials and Methods: In this clinical trial study, 28 patients older than 15 years with AR randomly divided into probiotics and control groups. The probiotics group received standard therapy for AR accompanied by probiotic capsules every 12 hours for eight weeks, whereas the control group received standard therapy for AR with placebo capsules as the same protocol. Data were analyzed using SPSS Version 23 (IBM Corporation, Armonk, NY, USA) and, the P-value less than 0.05 was considered statistically significant. Results: In the probiotics group, 14.3% of patients had sneezing at the baseline, which significantly decreased to 4.6% (P<0.01). Also, the necessity for nasal and oral corticosteroids after treatment with probiotics in the probiotics group was less than the control group (P<0.01). Although cough, nasal discharge, conchae hypertrophy, and night sleep disorders reduced after treatment with probiotics, this reduction was not statistically significant between the two groups. Conclusion: Based on the results of this clinical trial, the use of probiotics had no significant effect on the outcome of patients with AR. [GMJ.2020;9:e1918]

Effects of Probiotics on Allergic Rhinitis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

“…A total of 43 full articles were reviewed and 30 were excluded (cross-sectional studies, protocol studies, inactivated/non-viable probiotic studies, studies that evaluating safety, no full text available, and non-relevant clinical outcomes), resulting in 13 RCTs for our systematic review. [17][18][19][20][21][22][23][24][25][26][27][28][29] As nine probiotic strains or mixtures did not have a second confirmatory trial and one trial did not share a common outcome, 22 only four trials assessing two different types of probiotics were eligible for the meta-analysis. 20,21,23,24…”

“…In one study, randomization did not produce equal groups (n = 60 to probiotic vs. n = 20 to control). 23 Of the 13 trials, all used placebos as controls and 12 trials were double-blinded, [17][18][19][20][21][22][23][24][25][27][28][29] and one was single-blinded. 26 The placebo in 13 trials used the same appearance and was provided in the same delivery form as the probiotic to patients; either in the form of milk, 17,19,23,26 chewable tablet, 22 can, 25 sachet 18,27 or capsules.…”

“…Of the 13 trials, four used one of three different multi-strain mixtures, [26][27][28][29] as shown in Table 1. One trial used a mixture of two different types of Lactobacilli (L. casei and L. acidophilus), 26 but failed to report strain designations.…”

“…28,29 The duration of probiotic treatments ranged from 4 to 8 weeks and only one trial reported post-study medication follow-up. 29 The number of study participants ranged from 7 to 40 per trial. [26][27][28][29]…”

Probiotic Bacteria in Microbiome against Allergy

“…On these bases, probiotic bacteria are capable of altering immune responses through a range of mechanisms that could minimize allergic reactions to airborne allergens without the side effects of any current drugs, and these possible mechanisms, as shown in Figure 1, include regulatory T cells that dampen immune responses and suppress the production of IgE antibodies [92,93]. There are contradictory studies about the effectiveness of probiotics in treating allergic rhinitis [94]. It is reported that L. casei decreased the number of episodes of rhinitis in 64 preschoolers with allergic rhinitis [95].…”