In children, upper respiratory tract infections (URTIs) are one of the most common causes of infections which often require outpatient consultations with the doctor. The purpose of this study was to evaluate the effect of probiotic Bacillus clausii UBBC-07 on symptom management of URTIs in children. In this double blind, randomised, placebo-controlled study, 90 children (age 4-7 years) with URTIs were equally divided into two groups, the probiotic and placebo. The children were instructed to take B. clausii UBBC-07 spores (2×109 per 5 ml vial) or placebo suspension daily twice for three months. The total duration of the study was 6 months, 3 months treatment and 3 months follow-up period. The parameters assessed were the mean number of URTIs, duration and severity of URTIs, absenteeism from school/childcare and immunity parameters, such as immunoglobulin (Ig)M, IgG, IgE and salivary IgA levels. At the end of treatment, there was a significant decrease in the number, duration and severity of URTIs in the probiotic treated group as compared to the baseline and placebo. IgE levels were significantly decreased and salivary IgA levels were significantly increased in the probiotic treated group suggesting probiotic mediated Th1/Th2 immune homeostasis to alleviate URTIs in children. In conclusion, B. clausii UBBC-07 may help in the reduction of symptoms of URTIs.

The trial was registered prospectively with the Clinical Trial Registry of India (CTRI Reg. No: CTRI/2018/08/015282).