Crying Time and RORγ/FOXP3 Expression in Lactobacillus reuteri DSM17938-Treated Infants with Colic: A Randomized Trial

OBJECTIVES: To evaluate crying time, retinoid-related orphan receptor-γ (RORγ) and forkhead box P3 (FOXP3) messenger RNA levels (transcription factors that can modulate T cell responses to gut microbes), and to investigate gut microbiota and fecal calprotectin in infants treated with Lactobacillus reuteri for infantile colic. STUDY DESIGN: colony forming unit) or placebo for 1 month. Daily crying times were recorded in a structured diary. FOXP3 and RORγ messenger RNA in the peripheral blood was assessed with real-time TaqMan reverse transcription polymerase chain reaction. Gut microbiota and fecal calprotectin were evaluated. RESULTS: After infants with colic were supplemented with L reuteri DSM 17938 for 30 days, crying times were significantly shorter among infants with colic in the probiotic group compared with infants in the placebo group (74.67 ± 25.04 [IQR = 79] minutes /day vs 147.85 [IQR = 135] minutes /day [P = .001]). The FOXP3 concentration increased significantly (P = .009), resulting in decreased RORγ/FOXP3 ratios: 0.61 (IQR = 0.60) at day 0 and 0.48 (IQR = 0.28) at day 30 (P = .028). Furthermore, the probiotic increased the percentage of Lactobacillus (P = .049) and decreased fecal calprotectin (P = .0001). CONCLUSIONS: Infants with colic treated with L reuteri for 30 days had a significantly decreased crying time and an increased FOXP3 concentration, resulting in a decreased RORγ/FOXP3 ratio. The treatment reduced fecal calprotectin. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00893711.