Integrative Review of Gut Microbiota and Expression of Symptoms Associated With Neonatal Abstinence Syndrome.

Background: Neonatal exposure and subsequent withdrawal from maternal substance use disorder are a growing problem and consequence of the current opioid epidemic. Neonatal abstinence syndrome (NAS) is defined by a specified cluster of symptoms with treatment guided by the expression and severity of these symptoms. The mechanisms or pathophysiology contributing to the development of NAS symptoms are not well known, but one factor that may influence NAS symptoms is the gut microbiota. Objectives: The purpose of this integrative review was to examine evidence that might show if and how the gut microbiota influence expression and severity of symptoms similar to those seen in NAS. Methods: Using published guidelines, a review of research studies that focused on the gut microbiome and symptoms similar to those seen in NAS was conducted, using the Cochrane, EMBASE, and Scopus databases, from 2009 through 2019. Results: The review results included findings of aberrant microbial diversity, differences in microbial communities between study groups, and associations between specific taxa and symptoms. In studies involving interventions, there were reports of improved microbial diversity, community structure, and symptoms. Discussion: The review findings provide evidence that the gut microbiota may play a role in modifying variability in the expression and severity of symptoms associated with NAS. Future research should focus on examining the gut microbiota in infants with and without the syndrome as well as exploring the relationship between symptom expression and aberrant gut microbiota colonization in infants with NAS. [ABSTRACT FROM AUTHOR]