Nutraceuticals and Pain Disorders of the Gut-Brain Interaction in Infants and Children: A Narrative Review and Practical Insights.

Different nutraceuticals are often considered by parents of infants and children with abdominal pain and disorders of the gut-brain interaction. Herb extracts and natural compounds have long been used in traditional medicine, but clinical pediatric trials are very limited. This narrative review based on relevant studies identified through a search of the literature in Pubmed and Medline updated to October 2023 focused on the effect of nutraceuticals in infantile colic, functional abdominal pain, and irritable bowel syndrome in children and adolescents. Significant reductions in colic episodes and crying time were reported in two studies on fennel (seeds oil or tea), in three studies on different multiple herbal extracts (all including fennel), in one study on Mentha piperita , and in at least two double-blind randomized controlled studies on Lactobacillus reuteri DSM 17938 and Bifidobacterium lactis BB-12 (10 8 CFU/day for at least 21 days) in breast-fed infants. Compared to a placebo, in children with functional abdominal pain or irritable bowel syndrome, a significant reduction in pain was reported in two studies supplementing peppermint oil capsules or psyllium fibers, and in one study on corn fiber cookies, partial hydrolyzed guar gum, a specific multiple herbal extract (STW-5), or vitamin D supplementation. To date, there is moderate-certainty evidence with a weak grade of recommendation on Lactobacillus reuteri DSM 17938 (10 8 CFU/day) in reducing pain intensity in children with functional abdominal pain and for Lactobacillus rhamnosus GG (1-3 × 10 9 CFU twice daily) in reducing pain frequency and intensity in children with IBS. Further large and well-designed pediatric studies are needed to prove the efficacy and safety of different herbal extracts and prolonged use of studied products in infants and children with pain disorders of the gut-brain interaction.