# Prebiotics, probiotics, and synbiotics and maternal mental health during pregnancy and postpartum period: a systematic review

## TL;DR

This review examines whether prebiotics, probiotics, and synbiotics can help prevent depression and anxiety in pregnant and postpartum women without prior mental health issues.

## Contribution

The study is the first systematic review to evaluate the potential of gut microbiota-targeted dietary interventions in preventing maternal mental health disorders.

## Key findings

- Probiotics showed small but significant reductions in depressive and anxiety symptoms during pregnancy.
- One trial found significantly lower depressive scores in the probiotic group postpartum.
- No studies on prebiotics or synbiotics were found, and evidence remains limited due to heterogeneity.

## Abstract

Depression and anxiety are common during pregnancy and postpartum, affecting both mothers’ and offspring health. Emerging research suggests gut microbiota may influence these conditions, providing a potential non-pharmacological approach for primary prevention, particularly in women without a prior mental health diagnosis.

To assess the effect of prebiotics, probiotics, and synbiotics as dietary interventions targeting gut microbiota for preventing mental health disorders during pregnancy and postpartum in women without diagnosed mental health disorders.

The protocol was prospectively registered in PROSPERO (CRD42024576678). A comprehensive search of MEDLINE, EMBASE, CINAHL, The Cochrane Library (CENTRAL), Scopus, and Web of Science from inception to March 2025, without language restriction. Randomized controlled trials (RCTs) involving pregnant or early postpartum women without a diagnosed mental health disorder, evaluating prebiotics, probiotics, or synbiotics and reporting maternal mental health outcomes, were included. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool.

Of the 1,401 records identified, four RCTs (n = 1,342 women) met the inclusion criteria. All RCTs evaluated probiotics interventions, none assessed prebiotics or synbiotics. Of four, two RCTs using Lactobacillus rhamnosus HN001, Limosilactobacillus reuteri PBS072 and Bifidobacterium breve reported small but significant reductions in depressive symptoms [Edinburgh Postnatal Depression Scale, MD = −1.2; 95% CI (−2.3, −0.1)] and anxiety symptoms [State–Trait Anxiety Inventory-6: MD = −1.0; 95% CI (−1.9, −0.2); p < 0.05)] during pregnancy. One RCT showed significantly lower depressive scores in the intervention group at day 45 (mean 9.0 ± 4.8 vs. 12.1 ± 5.9; p < 0.001) and day 90 (7.0 ± 3.3 vs. 10.8 ± 6.2; p < 0.001) of postpartum compared to placebo. No pooled analyses were conducted due to heterogeneity. Risk of bias was moderate in three RCTs and high in one, primarily due to selective outcome reporting.

Evidence on the effect of probiotics for preventing maternal mental health disorders during pregnancy and postpartum is limited. There were no data on prebiotics or synbiotics. Strain specific probiotic effectiveness studies, as well as studies on prebiotics and synbiotics are required in the future.

PROSPERO, identifier (CRD42024576678).