Effect of an 8-Week Bifidobacterium lactis HN019 Supplementation on Functional Constipation: A Multi-Center, Triple-Blind, Randomized, Placebo-Controlled Trial

Functional constipation (FC) is characterized by difficult, infrequent, or incomplete bowel movements without clear physiological cause. Daily intake of Bifidobacterium lactis HN019 has been shown to reduce colonic transit time or increases bowel movement frequency in 2–4 weeks interventions. This triple-blind, randomized, placebo-controlled clinical trial assessed the effect of 8 weeks HN019 supplementation on complete spontaneous bowel movement (CSBMs) in adults with FC (diagnosed by Rome III criteria). Furthermore, stool consistency, degree of straining, abdominal pain severity, bloating severity, PAC-SYM, PAC-QoL, and use of rescue medication were assessed. Participants were screened at four clinical units in France for 2 weeks to confirm eligibility: no safety concerns, ≤3 CSBMs/week (recorded in daily diaries), followed by an 8-week intervention with daily supplementation of HN019 or placebo. HN019 was not found to be superior in managing FC compared to placebo. Fecal samples were collected from 50% of the participants for analyses of moisture content, microbiota, microbial metabolites, and calprotectin. These did not show any significant differences between the groups. This study did not support the expected effect of HN019 on improving CSBM frequency in participants with FC. No safety concerns related to B. lactis HN019 supplementation were identified.