A 10-year follow-up of a randomized controlled trial reports that early supplementation with Lactobacillus reuteri DSM 17938 in infants with functional gastrointestinal disorders such as colic and constipation was associated with a markedly lower prevalence of functional abdominal pain (FAP) at age 10 compared to placebo (13.1% vs 80.2%, p < 0.001). FAP was diagnosed using Rome IV criteria by a blinded pediatric gastroenterologist, with results indicating a relative risk of 0.16. While the findings suggest that early microbiome modulation may have lasting benefits, researchers note that the observational nature of the follow-up and substantial attrition limit conclusions about causality.