Characterizing the Intestinal Microbiome in Infantile Colic: Findings Based on an Integrative Review of the Literature.

Approximately 20% of newborns will develop symptoms of infantile colic starting around 2 weeks of age. While health care providers have a greater understanding of the impact that inconsolable crying has on family dynamics, maternal-infant bonding, and health care resources, opportunities for study still exist in the area of intestinal microbiome research. Advances in molecular technologies utilizing 16S ribosomal RNA and ribosomal DNA created the opportunity for researchers to index the intestinal microbial composition to better understand its association with infantile colic. This integrative review provides a synopsis of the findings from five recent studies that utilized nonculture-based approaches to characterize the intestinal microbiome of infants with colic. Articles were identified through PubMed, CINAHL, and Google Scholar using the search terms colic, crying, fussiness, microbiome, and microbiota. The general aim of the research studies was to better understand the potential association of intestinal dysbiosis with the development of colic symptoms. The research found that infants who expressed symptoms of colic were colonized with significantly higher levels of Proteobacteria and exhibited lower bacterial diversity when compared to their unaffected counterparts. Additionally, colonization levels of Actinobacteria Bifidobacterium and Firmicute Lactobacilli were inversely related to the amount of crying and fussiness in newborns. The observed association of an imbalanced colonization of the intestines by noncommensal bacteria with the expression of infantile colic symptoms warrants further exploration.