A Scoping Review of Neonatal Opioid Withdrawal and the Infant Gut Microbiome: Does Human Milk Optimize Infant Outcomes?

Background: While a growing body of literature has established the role of human milk as a mechanism of protection in the formation of the infant gut microbiome, it remains unclear the extent to which this association exists for infants with neonatal opioid withdrawal syndrome. Purpose: The purpose of this scoping review was to describe the current state of the literature regarding the influence of human milk on infant gut microbiota in infants with neonatal opioid withdrawal syndrome. Data Sources: CINAHL, PubMed, and Scopus databases were searched for original studies published from January 2009 through February 2022. Additionally, unpublished studies across relevant trial registries, conference proceedings, websites, and organizations were reviewed for possible inclusion. A total of 1610 articles met selection criteria through database and register searches and 20 through manual reference searches. Study Selection: Inclusion criteria were primary research studies, written in English, published between 2009 and 2022, including a sample of infants with neonatal opioid withdrawal syndrome/neonatal abstinence syndrome, and focusing on the relationship between the receipt of human milk and the infant gut microbiome. Data Extraction: Two authors independently conducted title/abstract and full-text review until there was consensus of study selection. Results: No studies satisfied the inclusion criteria, which resulted in an empty review. Implications for Practice and Research: Findings from this study document the paucity of data exploring the associations between human milk, the infant gut microbiome, and subsequent neonatal opioid withdrawal syndrome. Further, these results highlight the timely importance of prioritizing this area of scientific inquiry.