Gestational diabetes mellitus (GDM) is among the most prevalent metabolic disorders in pregnancy and is associated with a range of short- and long-term consequences for mother and child. The prevalence of anxiety and depression in pregnant people with GDM is reported to be two to four times higher than in healthy pregnant populations. Psychobiotics—interventions that may modify the gut–brain axis—have been proposed to improve cognitive and emotional function. This trial protocol was developed to evaluate whether prophylactic use of a synbiotic supplement or adherence to a psychobiotic diet during pregnancy can reduce antenatal and postpartum mood and anxiety symptoms in women with GDM who do not have clinically significant depressive symptoms or psychiatric disorders at baseline.
The primary outcomes of the trial are antenatal depression and pregnancy-related anxiety measured at 38 weeks’ gestation. Secondary outcomes include postpartum depression and anxiety assessed at 4–6 weeks after birth, maternal metabolic indices measured at 38 weeks, and selected maternal and neonatal outcomes immediately after delivery.
This is a randomized, controlled, three-arm parallel clinical trial. A total of 102 pregnant women diagnosed with GDM between 24 and 28 weeks of gestation will be randomized in equal allocation (1:1:1) to one of three groups. The interventions commence at the time of GDM diagnosis (reported as 28 weeks of gestation in the source) and continue until 4 weeks postpartum. The source does not provide additional details on study sites beyond the institutional ethics approval.
Eligible participants are pregnant women diagnosed with GDM between 24 and 28 weeks of gestation who do not have clinically significant depressive symptoms or other psychiatric disorders at baseline. The source does not report additional inclusion or exclusion criteria, specific recruitment settings, or exact screening procedures beyond this description.
Participants will be randomly assigned to one of three groups:
Regardless of assignment, all participants receive a standardised healthy diet education session consistent with protocols from the Iranian Ministry of Health. The intervention period extends from GDM diagnosis (28 weeks) until 4 weeks postpartum. The source does not report the specific synbiotic formulation, dosage, or the detailed components of the psychobiotic diet in the published summary.
Randomisation will be performed using block randomisation and stratified by parity. Allocation is in a 1:1:1 ratio across the three arms. Data analysis is planned according to a modified intention-to-treat approach. A per-protocol analysis will also be conducted for participants demonstrating an adherence rate of ≥90%.
Outcomes will be assessed using multiple sources:
The source does not specify timing of interim assessments, the exact laboratory measures to be used for metabolic indices, or who will administer the questionnaires.
Data will be analysed according to a modified intention-to-treat principle. A per-protocol analysis will be performed for participants with ≥90% adherence to their assigned intervention. The source does not provide full details of the statistical methods, sample size justification, handling of missing data, subgroup analyses, or adjustment procedures.
The study protocol has received ethics approval from the Ethics Committee of Tabriz University of Medical Sciences (IR.TBZMED.RCE.1404.565). The investigators plan to disseminate findings via peer-reviewed journals and presentations at scientific conferences. The trial is registered with the Iranian Registry of Clinical Trials under IRCT20220926056046N7.
Where the source summary did not provide details, those specifics are not reported here. Missing information in the source includes the exact synbiotic composition and dosage, detailed content and implementation of the psychobiotic diet, blinding and placebo description, full eligibility criteria, sample size calculation details, data monitoring procedures, and comprehensive statistical analysis methods.