Early Insights Into Maternal Antidepressant Use and the Human Infant Gut Microbiome

Maternal selective serotonin reuptake inhibitor (SSRI) use is common during pregnancy and lactation. Changes in serotonin signaling may affect diversity and composition of microbes in the gut. Although research suggests SSRI drives microbial change, the extent to which the infant gut microbiome is affected is unknown. The infant gut microbiome is critical in early life for support of developmental health including early training of the immune system and metabolic programming. A total of N = 20 (10 SSRI, 10 control) maternal/infant dyads were enrolled in a pilot study. Thirty-six infant stool samples were collected at 1-2 and 4-6 weeks of life and sequenced using 16S rRNA sequencing. Investigative models included SSRI exposure as the primary variable of interest with infant feeding pattern and mode of delivery included as covariates. Maternal antidepressant use was not associated with infant alpha (within-sample) diversity. The SSRI use may shape beta (between-sample) diversity, particularly at weeks 4-6 of life (p = .072). Increases in the genera Gemella, Staphylococcus and Corynebacterium were observed with SSRI exposure. Additionally, results reveal a SSRI-associated decrease in Lactobacillus. While this pilot study is not intended to provide conclusive evidence, it is an important step in informing future research directions. Results suggest a modest influence of maternal SSRI exposure on the infant gut microbiome. Future studies should seek to use techniques like metagenomics, providing functional information to assess for local or systemic health impact and ultimately, clinical relevance.