Sex-dependent efficacy of dietary fiber in pediatric functional abdominal pain

Authors: SO, SIK YU - Baylor College Of Medicine; BADU, SHYAM - Baylor College Of Medicine; WU, QINGLONG - Baylor College Of Medicine; YALCINKAYA, NAZLI - Baylor College Of Medicine; MIRABILE, YIMING - Children'S Nutrition Research Center (CNRC); CASTANEDA, ROBERT - Children'S Nutrition Research Center (CNRC); MUSAAD, SALMA - Children'S Nutrition Research Center (CNRC); HEITKEMPER, MARGARET - University Of Washington; SAVIDGE, TOR - Baylor College Of Medicine; SHULMAN, ROBERT - Children'S Nutrition Research Center (CNRC)

Submitted to: Gastroenterology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2023
Publication Date: 12/18/2023
Citation: So, S., Badu, S., Wu, Q., Yalcinkaya, N., Mirabile, Y., Castaneda, R., Musaad, S., Heitkemper, M., Savidge, T.C., Shulman, R.J. 2023. Sex-dependent efficacy of dietary fiber in pediatric functional abdominal pain. Gastroenterology. 166(4):645-657. https://doi.org/10.1053/j.gastro.2023.12.011.
DOI: https://doi.org/10.1053/j.gastro.2023.12.011

Interpretive Summary: It is recommended that children and adults eat more fiber and some studies have shown that doing so can reduce the amount of belly pain in children and adults with irritable bowel syndrome, a disorder that affects approximately 10 out of 100 people worldwide. We showed for the first time that additional fiber in the diet can improve belly pain symptoms in boys but does not appear to help girls. This information is important in determining which treatments to use based on the sex of the child.

Technical Abstract: Functional abdominal pain disorders (FAPDs) are more prevalent in female patients. Dietary fiber may alleviate FAPD symptoms; however, whether this effect is sex dependent remains unclear. We investigated the sex dependency of dietary fiber benefit on abdominal pain in children with FAPDs and explored the potential involvement of the gut microbiome. In 2 cross-sectional cohorts of children with FAPDs (n = 209) and healthy control individuals (n = 105), we correlated dietary fiber intake with abdominal pain symptoms after stratifying by sex. We also performed sex-stratified and sex-interaction analyses on data from a double-blind trial in children with irritable bowel syndrome randomized to psyllium fiber (n = 39) or placebo (n = 49) for 6 weeks. Shotgun metagenomics was used to investigate gut microbiome community changes potentially linking dietary fiber intake with abdominal pain. In the cross-sectional cohorts, fiber intake inversely correlated with pain symptoms in boys (pain episodes: r = -0.24, P = .005; pain days: r = -0.24, P = 0.004) but not in girls. Similarly, in the randomized trial, psyllium fiber reduced the number of pain episodes in boys (P = .012) but not in girls. Generalized linear regression models confirmed that boys treated with psyllium fiber had greater reduction in pain episodes than girls (P = .007 for fiber × sex × time interaction). Age, sexual development, irritable bowel syndrome subtype, stool form, and microbiome composition were not significant determinants in the dietary fiber effects on pain reduction. Dietary fiber preferentially reduces abdominal pain frequency in boys, highlighting the importance of considering sex in future dietary intervention studies for FAPDs.