Altered fecal microflora and increased fecal calprotectin in infants with colic.

Objective: We explored whether gut inflammation, colonic fermentation, and/or an altered colonic flora could provide a pathophysiological mechanism for colic.

Study Design: The study population consisted of 36 term infants ranging in age from 14 to 81 days. We measured fecal calprotectin (a marker of neutrophil infiltration) by ELISA; stool microorganisms by denaturing gradient gel electrophoresis, cloning, and sequencing; and breath hydrogen levels using gas chromatography.

Results: During 24 hours, infants with colic (n = 19) cried and fussed for a mean of 314 +/- 36 (SEM) minutes, compared with control infants (n = 17, 103 +/- 17 minutes). Fecal calprotectin levels were 2-fold higher in infants with colic than in control infants (413 +/- 71 vs 197 +/- 46 microg/g, P = .042). Stools of infants with colic had fewer identifiable bands on denaturing gradient gel electrophoresis. Klebsiella species were detected in more colic patients than in control patients (8 vs 1, P = .02), whereas Enterobacter/Pantoea species were detected only in the control patients. These differences could not be attributed to differences in formula versus breast milk feeding, consumption of elemental formula, or exposure to antibiotics.

Conclusions: Infants with colic, a condition previously believed to be nonorganic in nature, have evidence of intestinal neutrophilic infiltration and a less diverse fecal microflora.