In a substudy of the Bibo study, a prospective longitudinal investigation of the influences of early caregiving practices on developmental outcomes, researchers from the Netherlands and Finland characterized the differences in microbiota diversity among 12 infants with and 12 infants without clinical diagnoses of colic. A comprehensive analysis of more than 1,000 intestinal phenotypes from more than 200 stool specimens was performed through the extraction and hybridization of stool DNA to a phylogenetic microarray. Results demonstrated a decreased microbial diversity among infants before they developed clinical symptoms of colic than those who did not have colic. Proteobacteria (Escherichia, Klebsiella, Serratia, Vibrio, Yersinia and Pseudomonas) were increased and lactobacilli and Bifidobacteria, as well as other butyrate-producing organisms, were comparatively decreased in infants in their first weeks of life who later developed colic, defined as crying for an average of greater than 3 hours per day.
This prospective temporal assessment of intestinal microbiota in infants with and without colic provides a detailed description of the interaction between stool microbiota diversity and symptoms of colic in the first 3 months of life. Both the detailed laboratory analyses and the comprehensive statistical analyses of generated data affirm results from point-prevalence studies also demonstrating decreased microbiota diversity in symptomatic infants. The demonstration of differences in microbiota composition from stools in the first weeks of life before the onset of colic symptoms may facilitate prediction of infants at risk of developing colic.
Alterations in intestinal microbiota resulting in increased gas production by dominant organisms have been hypothesized to result in changes in gut motility, expressed as the clinical symptoms of colic. Between 6% and 29% of infants experience colic and 17% of caretakers of colicky infants seek assistance to manage the resulting distress resulting from their infant’s behavior.
Limitations of the study include a moderate sample size and homogeneity of the infant cohort, which could limit generalizability. Although uneventful prenatal and postnatal histories were inclusion criteria, maternal and infant antibiotic use, probiotic supplementation, and use of other remedies for colic were not described.
Furthermore, although breast-feeding duration was comparable between the infants with and without colic, twice as many infants with colic never received human milk. The authors also do not specify whether breast-feeding was exclusive or whether infants received formula supplementation. Finally, the description of intercurrent gastrointestinal infections that could have impacted microbiota composition were not described.
Evaluations of interventions to manage colic have been limited by the natural history of the condition in which crying associated with colic subsides by 4 months of age. Cultural remedies, nutritional supplements, and alterations in the composition of breast-feeding mothers and their infant’s diets have had varying impacts on the reduction of crying symptoms. The results of this study provide biological plausibility to suggest that interventions, such as the administration of butyrate-producing lactobacilli and mucosal lactobacilli species with anti-inflammatory properties, may supplement the developing microbiota and could prevent the aberrations in flora that appear to be associated with colic.
Although the clinical symptoms of colic last for a defined period, they occur during an important period of infant development when patterns of behavior, feeding and interaction are established. Identifying at-risk infants and considering interventions, such as probiotic supplementation, may decrease the burden of this prevalent and challenging condition.
Andi L. Shane, MD, MPH, MSc
Infectious Diseases in Children Editorial Board
Disclosures: Shane has received a research grant from the Gerber Foundation to assess the impact of the administration of a commercially available Lactobacillus–containing probiotic on immune response to rotavirus vaccine administration in infants. She has also received travel and conference support to make presentations at International Scientific Association for Probiotics and Prebiotics (ISAPP) meetings.