Supplementation with Lactobacillus rhamnosus HN001 reduced mothers’ levels of post-natal depression and anxiety during the period between 1 and 2 months after they had given birth. Compared with placebo, the supplementation group also showed significantly fewer mothers with anxiety above clinically significant cut-off levels.
The probiotic strain has been trademarked as DR20 and SureStart LactoB 001 by Fonterra Co-operative Group, Ltd, New Zealand, who contributed funds to the trial.
Post-natal depression and anxiety were secondary outcomes in the Probiotics in Pregnancy (PIP) Study conducted by researchers from the University of Auckland and the University of Otago. (The primary trial outcome was incidence of eczema in the infants at 12 months).
“Women who received HN001 had significantly lower depression and anxiety scores in the postpartum period. This probiotic may be useful for the prevention or treatment of symptoms of depression and anxiety postpartum,” wrote first author Dr. Rebecca Slykerman.
The findings are significant as probiotic interventions might eventually be used as routine pregnancy care to prevent depression, should future trials confirm these results.
The study was a randomised double-blinded placebo controlled trial of 423 healthy New Zealand women. The participants were randomised either to a daily dose of 6 billion colony-forming units (cfu) of L. rhamnosus HN001 or to placebo. The supplement and placebo groups received treatments from recruitment at 14-16 weeks gestation through to 6 months after the infants’ birth.
Mothers completed a retrospective questionnaire when their child was 6 months and 12 months old regarding their psychological wellbeing when the baby was 1-2 months old.
The researchers measured maternal mood using the Edinburgh Postnatal Depression Scale (EPDS) and anxiety using the State Strait Anxiety Inventory 6 item version (STAI6).
The scientists also found that “infant colic was associated with higher depression and anxiety scores.” Previous research had suggested that probiotic supplementation reduced infant colic, which in turn was correlated with lower maternal depression. Therefore, the researchers in this study also looked at results after adjusting for infant colic as a potential confounder.
The findings remained unaltered with or without this adjustment.
“This study provides evidence that probiotic supplementation with L. rhamnosus HN001 in pregnancy and postpartum reduces the prevalence of symptoms of PND and anxiety postpartum,” concluded the team.
Despite the promising results, the researchers nevertheless cautioned that the probiotic-induced benefits might be strain specific and dose-dependent.
“Not all probiotic strains have the same effect on health and it is possible that the results found using HN001 are not generalisable to other probiotic strains, or at lower doses than those used in this study,” they explained.
“There are many unanswered questions,” the authors added, “including the choice of probiotic, the dose and the duration of treatment. Can probiotics prevent the onset of symptoms? Could probiotics be used as the primary treatment for maternal mental health problems or should it be used as an adjuvant treatment to standard therapy?”
Suggesting topics for further research, the team highlighted the potential for therapeutic treatment with probiotics.
“Such studies might incorporate inflammatory markers, cortisol, or other objective markers. If replicated by other studies, this probiotic may be useful for the prevention or treatment of symptoms of depression and anxiety.”
Published online: DOI: 10.1016/j.ebiom.2017.09.013
“Effect of Lactobacillus rhamnosus HN001 in Pregnancy on Postpartum Symptoms of Depression and Anxiety: A Randomised Double-blind Placebo-controlled Trial”
Authors: R.F. Slykerman et al