Long-Term Efficacy of Limosilactobacillus reuteri DSM17938 in the Prevention of Functional Abdominal Pain Disorders

Introduction: Pediatric Functional Gastrointestinal Disorders (FGIDs), including infantile colic and constipation, may persist into later childhood and adulthood, sometimes manifesting as functional abdominal pain (FAP). Early exposure to probiotics during critical developmental windows may influence long-term susceptibility to disease. Background/Objectives: Building on our original randomized controlled trial, which demonstrated that Lactobacillus reuteri DSM 17938 reduced acute infantile FGID symptoms, a 10-year follow-up study was performed to evaluate whether this early intervention provided lasting protection against FAP in childhood. Methods: Two hundred participants from the original RCT cohort completed follow-up assessments at age ten. The primary outcome was the presence of FAP, analyzed according to the original randomization group (probiotic vs placebo). FAP was diagnosed at age 10 using the Rome IV criteria, based on a standardized clinical assessment by a pediatric gastroenterologist who was blinded to the original allocation. Results: FAP was diagnosed in 13/99 (13.1%) children in the probiotic group and 81/101 (80.2%) in the placebo group, corresponding to an absolute risk reduction of 67.1% (95% CI 56.8–77.3) and a relative risk of 0.16 (95% CI 0.10–0.27) (p < 0.001). Conclusions: Early supplementation with L. reuteri DSM 17938 was associated with a markedly lower prevalence of FAP at age 10. However, the long-term follow-up was observational and characterized by a 57.2% attrition rate. In addition, longitudinal data on potential confounders were unavailable; therefore, the findings should be interpreted as an association rather than proof of causality.