Intake safety of Lactobacillus helveticus SBT2171 and its effects on nasal and ocular symptoms associated with mites and house dust: An open-label study and a randomized, double-blind, placebo-controlled, parallel group study

Abstract

Background: We previously reported that Lactobacillus helveticus SBT2171 (LH2171) inhibited the proliferation and secretion of lipopolysaccharide-stimulated inflammatory cytokines in primary immune cells. Furthermore, in vivo administration of LH2171 has been demonstrated to suppress the incidence and development of murine rheumatoid arthritis. In this study, we evaluated whether the intake of drinkable yogurt (DY) containing LH2171 alleviated nasal and ocular symptoms of allergy to mites and house dust allergens. The safety of LH2171 was also confirmed in an independent, open-label study in 20 healthy subjects who consumed an excessive amount of LH2171.Methods: In study 1, the effect of daily intake of DY containing LH2171 for 12 weeks on nasal and ocular symptoms was evaluated in healthy men and women who tested positive for house dust or mite-specific IgE in a randomized, double-blind, placebo-controlled, parallel group study. One hundred subjects were divided into two groups: subjects taking placebo DY (P group, n = 50) and subjects taking DY containing approximately 1 × 109 cells of LH2171 (LH2171 group, n = 50) daily for the 12 weeks. After excluding subjects that met exclusion criteria, data obtained from 94 subjects (LH2171 group: n = 48; P group: n = 46) were analyzed to establish LH2171 efficacy. LH2171 safety was assessed in an independent, open-label trial in 20 subjects (study 2) who consumed an excessive amount of DY containing approximately 3 × 109 LH2171 cells.Results: In study 1, the decreases in the total scores of the nasal and ocular discomfort between week 0 and week 8 in LH2171 group were significantly larger than those in P group. Additionally, the number of sneezes decreased significantly in LH2171 group compared with P group on weeks 9–12 compared to the number of sneezes at baseline. In study 2, no adverse effects of LH2171 on systolic bold pressure, diastolic blood pressure, pulse rate, body weight, blood and urinalysis parameters were reported.Clinical trial registration: UMIN000027791 (study 1), UMIN000029058 (study 2).Conclusion: Daily intake of LH2171 for 12 weeks may regulate immune function and improve nasal and ocular symptoms in the subjects with mite or house dust allergy.