Influence of postpartum depression and probiotic treatment on maternal brain serotonin and caregiving behaviours

A Research by Dr. Jodi Pawluski (Rennes, France) and Dr. Joseph Lonstein (Michigan State University, USA)

Postpartum depression (PPD) is a very common, but poorly understood, disorder that negatively affects more than 15% of the millions of recently parturient women worldwide.

One of the key neurotransmitter systems involved in PPD is serotonin. However, little is known about the functioning of the serotonergic system during the peripartum period in the face of PPD or even under healthy postpartum conditions.

Given the growing body of evidence linking gut microbiota to brain chemistry and mental illness, dietary supplements such as probiotics are valuable candidates to improve symptoms of PPD. Although it has not been well studied with regards to postpartum mental illness, one study already suggests that probiotic treatment may protect against or alleviate symptoms of PPD in women (Slykerman et al., 2017) and it may do so via the amino acid tryptophan and the neurotransmitter serotonin (which derives from tryptophan). Therefore, the goals of our BINC-Geneva funded research are to use pregnancy stress as a laboratory rat model of PPD to understand:

• How probiotic treatment affects the maternal gut-brain axis and postpartum affective behaviors?
• How pregnancy stress and probiotic treatment alter the central serotonergic system during the early postpartum period. We hypothesize that pregnancy stress to model PPD will derail the normative changes in maternal central serotonin system and gut, leading to depressive behaviors and poor maternal caregiving?

We expect that probiotic treatment will protect against this derailment.

The results of this novel research will greatly advance knowledge about the maternal gut-brain axis and have the potential to significantly improve the treatment of millions of women suffering from postpartum mental illness.