Effect of yoghurt containing Bifidobacterium lactis Bb12® on faecal excretion of secretory immunoglobulin A and human beta-defensin 2 in healthy adult volunteers

Abstract

Background: Probiotics are used to provide health benefits. The present study tested the effect of a probiotic yoghurt on faecal output of beta-defensin and immunoglobulin A in a group of young healthy women eating a defined diet. Findings. 26 women aged 18-21 (median 19) years residing in a hostel were given 200 ml normal yoghurt every day for a week, followed by probiotic yoghurt containing Bifidobacterium lactis Bb1 2 (10 9 in 200 ml) for three weeks, followed again by normal yoghurt for four weeks. Stool samples were collected at 0, 4 and 8 weeks and assayed for immunoglobulin A and human beta-defensin-2 by ELISA. All participants tolerated both normal and probiotic yoghurt well. Human beta-defensin-2 levels in faeces were not altered during the course of the study. On the other hand, compared to the basal sample, faecal IgA increased during probiotic feeding (P = 0.0184) and returned to normal after cessation of probiotic yoghurt intake. Conclusions: Bifidobacterium lactis Bb1 2 increased secretory IgA output in faeces. This property may explain the ability of probiotics to prevent gastrointestinal and lower respiratory tract infections. © 2011 Kabeerdoss et al; licensee BioMed Central Ltd.