<i>Lactiplantibacillus plantarum</i> Z6 Improves Functional Constipation in Infants

OBJECTIVE: To evaluate the efficacy and safety of Lactiplantibacillus plantarum Z6 (L. plantarum Z6) supplementation in infants with functional constipation (FC) and to explore its effects on gut microbiota composition. STUDY DESIGN: In this randomized, placebo-controlled trial, 100 infants diagnosed with FC were enrolled and allocated to receive either L. plantarum Z6 or placebo. Clinical outcomes, including weekly bowel movement frequency, Bristol stool scale scores, and Wexner constipation scores, were assessed. Serum 5-hydroxytryptamine (5-HT) levels and fecal microbiota profiles were analyzed to evaluate neurogastrointestinal and microbial responses. RESULTS: L. plantarum Z6 supplementation significantly increased weekly bowel movements and Bristol stool scores while reducing Wexner scores (p < 0.05). Serum 5-HT concentrations were elevated, indicating improved gastrointestinal motility. Gut microbiota analysis revealed enhanced α-diversity, higher abundances of Bifidobacterium, Gemmiger, and Lactobacillus, and reduced Streptococcus. Correlation analysis demonstrated a positive association between L. plantarum Z6 intake and Bifidobacterium enrichment, suggesting targeted modulation of beneficial taxa. CONCLUSIONS: L. plantarum Z6 is a safe and effective probiotic intervention for infantile functional constipation. The results highlight its potential to improve bowel function and beneficially reshape the gut microbiota, offering a microbiota-targeted therapeutic strategy for pediatric gastrointestinal disorders. Chinese Clinical Trial Registry ID: ChiCTR2300073079.