Limosilactobacillus reuteri trial designed to enhance mother-infant bonding and maternal socioemotional function

Postpartum depression (PPD) is a prevalent condition that significantly impairs early mother-infant bonding, with current interventions often having limitations. While oxytocin (OXT) is crucial for socioemotional adaptation, intranasal administration leads to supraphysiological exposure and inconsistent outcomes. The probiotic Limosilactobacillus reuteri (L. reuteri) has shown promise in rodents by increasing endogenous oxytocin levels, suggesting a potential to enhance OXT signaling via gut-brain pathways in humans. This trial addresses the need for safe, effective, and lactation-compatible strategies to support maternal mental health.

This proof-of-concept, randomized, double-blind, placebo-controlled trial enrolled mothers aged ≥18 years at elevated PPD risk (history of depression, prior PPD, and/or increased prenatal depressive symptoms). Participants received once-daily L. reuteri or placebo for 6 weeks, stratified by delivery mode. The primary endpoint is mother-infant bonding quality at Week 6, assessed via validated questionnaires. Secondary endpoints include maternal mental health, impulse control, and emotion recognition at Week 6. Salivary OXT at Week 2 serves as a mechanistic endpoint, measured using ELISA.

This abstract details the rationale and design, reporting on the initial enrollment and completion rates rather than efficacy results. The trial successfully enrolled 46 participants (mean age 34.3 ± 4.5 years). Of these, 38 participants (82.6%) completed the Week-6 visit, demonstrating high retention for a postpartum study. Baseline characteristics of the enrolled cohort were reported, confirming the population met the criteria for increased PPD risk. The study's conclusion emphasizes that future findings will provide crucial data on feasibility, safety, and effect size estimates of the L. reuteri intervention. This information will be vital for clarifying the mechanistic role of oxytocin in PPD pathophysiology and guiding the development of novel microbiome-based therapeutics. The trial is registered as ClinicalTrials.gov: NCT04472065. > The trial enrolled 46 participants, with 38 (82.6%) completing the Week-6 visit, indicating strong participant retention.