Infant Colic Represents Gut Inflammation and Dysbiosis.

OBJECTIVE: To dissect potential confounding effects of breast milk and formula feeding on crying + fussing, fecal calprotectin, and gut microbiota in babies with colic. We hypothesized that infant colic is associated with gut inflammation linked to intestinal dysbiosis. STUDY DESIGN: A nested case-control design of 3 of our studies was used to analyze clinical and laboratory data at presentation, comparing babies with colic with controls. All investigators other than the biostatistician were blinded during data analysis. Subjects were recruited based on their age and crying + fussy time. We screened 65 infants, 37 with colic, as defined by Barr diary (crying + fussing time >3 hours daily), who were compared with 28 noncolicky infants. RESULTS: Fecal calprotectin was elevated in babies with colic. For each mode of infant feeding (breast milk, formula, or breast + formula), infants' fecal calprotectin was higher in babies with colic. Infants with colic had similar levels of fecal alpha diversity (richness) when compared with controls, and alpha diversity was lower in breast-fed babies. Beta diversity at the phylum level revealed significant differences in microbial population. A phylum difference resulted from reduced Actinobacteria (95% of which are Bifidobacilli) in babies with colic. Species significantly associated with colic were Acinetobacter and Lactobacillus iners. CONCLUSIONS: Colic is linked with gut inflammation (as determined by fecal calprotectin) and dysbiosis, independent of mode of feeding, with fewer Bifidobacilli. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01279265 and NCT01849991.

Lactobacillus reuteri for Infants with Colic: A Double-Blind, Placebo-Controlled, Randomized Clinical Trial.

OBJECTIVE: To assess the safety of probiotic Lactobacillus reuteri strain Deutsche Sammlung von Mikroorganismen (DSM) 17938 with daily administration to healthy infants with colic and to determine the effect of L reuteri strain DSM 17938 on crying, fussing, inflammatory, immune, and microbiome variables. STUDY DESIGN: We performed a controlled, double-blinded, phase 1 safety and tolerability trial in healthy breast-fed infants with colic, aged 3 weeks to 3 months, randomly assigned to L reuteri strain DSM 17938 (5 × 108 colony-forming units daily) or placebo for 42 days and followed for 134 days. RESULTS: Of 117 screened infants, 20 were randomized to L reuteri strain DSM 17938 or placebo (sunflower oil) (in a 2:1 ratio) with 80% retention. Eleven of the 20 (55%) presented with low absolute neutrophil counts (<1500/mm3), which resolved in all subjects by day 176. L reuteri strain DSM 17938 produced no severe adverse events and did not significantly change crying time, plasma bicarbonate, or inflammatory biomarkers. Fecal calprotectin decreased rapidly in both groups. In the infants with dominant fecal gram negatives (Klebsiella, Proteus, and Veillonella), resolution of colic was associated with marked decreases in these organisms. CONCLUSIONS: Daily administration of L reuteri strain DSM 17938 appears to be safe in newborn infants with colic, including those with neutropenia, which frequently coexists. A placebo response of 66% suggests that many infants with colic will have resolution within 3 weeks. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01849991.

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.

Serum citrulline levels correlate with enteral tolerance and bowel length in infants with short bowel syndrome.

OBJECTIVE: To determine if serum levels of CIT (a nonprotein amino acid synthesized by the intestine) correlate with total parenteral nutrition (PN)-independence in children with short bowel syndrome (SBS). STUDY DESIGN: We prospectively obtained serum amino acid profiles over a 24-month interval from all infants with SBS 3 weeks to 4 years of age. Remaining small intestine length was recorded at surgery, and percent enteral calories tolerated (enteral calories divided by enteral plus parenteral calories x 100) was determined in 24 infants with SBS and 21 age-matched controls (blood drawn for non-gastrointestinal symptoms). RESULTS: Mean CIT for controls was 31 +/- 2 micromol/L. In patients with SBS (n = 24), serum CIT correlated linearly with percent enteral calories (R = 0.85; P <.001) and with bowel length (R = 0.47; P < or =.03). CIT level in patients with SBS weaned off PN was 30 +/- 2 micromol/L; in those subsequently weaned off PN, 20 +/- 2 micromol/L; and in those who would remain PN-dependent, 11 +/- 2 micromol/L ( P < or =.01). Serum CIT > or =19 micromol/L had 94% sensitivity and 67% specificity for being off or coming off total PN. CONCLUSIONS: Serum CIT level >19 micromol/L in children with SBS is associated with development of enteral tolerance and may be a useful predictive test.

Reduced serum amino acid concentrations in infants with necrotizing enterocolitis.

OBJECTIVE: To determine whether premature infants who have necrotizing enterocolitis (NEC) have deficiencies in glutamine (GLN) and arginine (ARG), which are essential to intestinal integrity. STUDY DESIGN: A 4-month prospective cohort study of serum amino acid and urea levels in premature infants was done. Serum amino acid and urea levels were measured by high-pressure liquid chromatography and enzymatic methods, respectively, on samples obtained on days of life 3, 7, 14, and 21. RESULTS: Infants in the control (n = 32) and NEC groups (n = 13) were comparable for birth weight, gestational age, and Apgar scores. NEC began on mean day of life 14.5 (95% CI, day of life 11 to 18). Median values of GLN were 37% to 57% lower in the NEC group on days 7, 14, and 21 compared with those in the control group (P <.05). On days 7 and 14, median values of ARG, GLN, alanine, lysine, ornithine, and threonine were decreased 36% to 67% (P <.05) in the NEC group. Total nonessential amino and total essential amino acids were 35% to 50% lower in the NEC group on days 7 and 14 (P <.05). Infants in the NEC group had significant reductions in GLN and ARG 7 days before the onset of NEC. CONCLUSIONS: Infants who have NEC have selective amino acid deficiencies including reduced levels of GLN and ARG that may predispose to the illness.