The impact of perinatal maternal stress on the maternal and infant gut and human milk microbiomes: A scoping review protocol

Objective The objective of this scoping review is to review the research evidence regarding the impact of perinatal maternal stress on the maternal and infant gut and human milk microbiomes. Introduction Perinatal stress which refers to psychological stress experienced by individuals during pregnancy and the postpartum period is emerging as a public health concern. Early exposure of infants to perinatal maternal stress can potentially lead to metabolic, immune, and neurobehavioral disorders that extend into adulthood. The role of the gut and human milk microbiome in the microbiome-gut-brain axis as a mechanism of stress transfer has been previously reported. A transfer of colonised aberrant microbiota from mother to infant is proposed to predispose the infant to a pro- inflammatory microbiome with dysregulated metabolic process thereby initiating early risk of chronic diseases. The interplay of perinatal maternal stress and its relationship to the maternal and infant gut and human milk microbiome requires further systematic examination in the literature. Inclusion criteria This scoping review is an exploratory mapping review which will focus on the population of mothers and infants with the exploration of the key concepts of maternal stress and its impact on the maternal and infant gut and human milk microbiome in the context of the perinatal period. It will focus on the pregnancy and the post-natal period up to 6 months with infants who are exclusively breastfed. Methods This study will be guided by the Joanna Briggs Institute’s (JBI) methodology for scoping reviews along with use of the Prisma Scr reporting guideline. A comprehensive search will be conducted using the following databases, CINAHL Complete; MEDLINE; PsycINFO, Web of Science and Scopus. A search strategy with pre-defined inclusion and exclusion criteria will be used to retrieve peer reviewed data published in English from 2014 to present. Screening will involve a three-step process with screening tool checklists. Results will be presented in tabular and narrative summaries, covering thematic concepts and their relationships. This protocol is registered with Open Science Framework DOI 10.17605/OSF.IO/ 5SRMV.