薬理と治療

Abstract

Background　It has been well established that water-soluble dietary fibers provide nutrition for microbiota in the large intestine. Among soluble dietary fibers, inulin has been well researched. There are many plants and vegetables that contain a high concentration of inulin, such as burdock and onion, and Japanese people commonly have consumed them for a long time. The effect of inulin intake on gut have been well known, but few studies have reported the effect on immunity. Objectives　The aim of the present study was to assess the efficacy of intake of inulin compared with the placebo over 6 week period on immunity, using secretory immunoglobulin A （sIgA）rate（speed）as the primary endpoint. Methods　We conducted a randomized, clinical parallel, double-blind, placebo-controlled trial study to assess the efficacy of the inulin intake on immunity. The 50 healthy elderly were divided by age and sex at baseline, into the inulin group, in which the subjects consumed the inulin, and the placebo group, in which the subjects consumed a placebo. Results　At week 6, the improvement of speed from baseline（week 0）in sIgA rate was observed in both groups（P＜0.01）. A significant interaction effect of pre╱post×groups in sIgA rate was observed（P＝0.045）. There was a significant difference between the inulin and placebo groups in the change of sIgA rate between pre and post（P＝0.045）. A significant higher level of change was observed in the inulin group compared with the palacebo group. Conclusions　The study indicated the intake of inulin intake improves immunity in the healthy elderly. （UMIN000041600）（Jpn Pharmacol Ther 2022；50：1855‒60）