薬理と治療

Abstract

Background The common cold is widespread and affects all ages and both genders. In many cases, it decreases the quality of life and work productivity. It has been reported that the intake of certain food materials can reduce the incidence or symptoms of the common cold, but the results are conflicting. One reason could be the differences in evaluation methods between studies. We reported that the intake of Lactobacillus pentosus strain b240（B240）decreased the incidence rate of the common cold with dose dependency. We excluded allergic patients from our study as their symptoms were similar to that of patients with common cold. However, several subjects took an anti-allergic drug during the study period. Therefore, we reanalyzed the data after excluding these subjects from the per protocol set and assessed whether their exclusion led to accurate estimation of the incidence of the common cold. Methods Data analyzed in this study were obtained from a previously reported, randomized, double-blind, placebo-controlled study of 300 healthy elderly adults, to estimate the reduction in common cold incidence by taking B240. We conducted subgroup analysis by excluding subjects who took an anti-allergy drug during the study period and reviewed the results. Results By excluding data for anti-allergy drug users, we confirmed that the intake of both 20 billion B240（P＝0.018）as well as the intake of 2 billion B240（P＝0.040）reduced the incidence of the common cold. This effect was dose-dependent. Conclusions Our results suggest that we can precisely evaluate the effect of food materials on the common cold by excluding data for those who took an anti-allergy drug during the study.