Reducing Pain and Anxiety Through Dietary Fiber Supplementation in Children With Abdominal Pain

Background - Mental health and pain problems in early childhood are major risk factors for serious mental health problems into adulthood. These long-term effects point toward the essential need for prevention and early intervention to curbing the rising tide of global mental health disease. New approaches to child and adolescent mental health are urgently needed. This study focus on children with functional abdominal pain (FAP), which is defined as recurrent abdominal pain independent of bowel movements without an underlying medical cause. This population has a high co-occurrence of anxiety and somatic complaints. The effects of fiber on gastrointestinal pain have not yet been tested in this group. The investigators propose that supplementation with dietary fiber (psyllium) in children with FAP will promote SCFA production by the gut microbiota, reducing abdominal pain and subsequently anxiety and improving quality of life. Psyllium promotes SCFA production, is considered safe, and meta-analyses have identified it as the most potent fiber for reducing abdominal complaints in IBS patients, indicating strong potential for reducing abdominal pain in children with FAP. It is essential that potential mechanisms through which psyllium-induced SCFA production can reduce abdominal pain and anxiety symptoms and improve quality of life are explored. This study will explore 3 mechanisms: 1) activation of the vagus nerve, as SCFAs can induce vagal signalling, and evidence suggests that vagus nerve stimulation can reduce pain and anxiety symptoms; 2) reduction in HPA-axis responsiveness, since fiber has been shown to do so in adults, and both abdominal pain and anxiety disorders are associated with increased HPA-axis activity; and 3) structural and functional brain changes in the amygdala and hippocampus, as SCFA can influence neuronal activity of specific brain regions and probiotics-induced improvements in mental health have been related to these brain regions in adults with