Emerging evidence of a role for gut microbiota on central nervous system functions suggests that oral intake of probiotics may have beneficial consequences on mood and psychological distress. The possible effects of a probiotic formulation consisting of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 (PF) on anxiety, depression, stress and coping strategies in healthy human subjects was evaluated in a double-blind, placebo-controlled randomized parallel group study. Subjects were administered PF for 30 days and assessed with the Hopkins Symptom Checklist (HSCL-90), the Hospital Anxiety and Depression Scale (HADS), the Perceived Stress Scale, the Coping Checklist (CCL) and 24 h urinary free cortisol (UFC). Daily administration of PF alleviated psychological distress in subjects, as measured particularly by the HSCL-90 scale (global severity index, P < 0.05; somatisation, P < 0.05; depression, P < 0.05; and anger–hostility, P < 0.05), the HADS (HADS global score, P < 0.05; and HADS-anxiety, P < 0.06), and by the CCL (problem solving, P < 0.05) and the UFC level (P < 0.05). The authors concluded that L. helveticus R0052 and B. longum R0175 taken in combination display beneficial psychological effects in healthy human volunteers. Br J Nutr. 2011 Mar;105(5):755-64. PMID: 20974015.
