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

 Research question & Objectives - The first objective is to provide a dietary fiber psyllium
 supplement to children (ages 8-16 years) who suffer from FAP. The aims are to: 1) determine
 whether psyllium reduces abdominal pain, 2) investigate whether this subsequently decreases
 anxiety and improves quality of life, and 3) assess associated gut-brain axis mediators,
 specifically the vagus nerve, HPA-axis, and brain networks.

 Methods - The investigators propose a 12-week placebo-controlled double-blind parallel-group
 intervention pilot study (n=20/group) where children suffering from FAP will receive a 5g
 daily supplement of either psyllium or placebo (maltodextrin) for 2 weeks to allow the
 gastrointestinal tract to acclimatize to the increase in dietary fiber, after which children
 will receive 10g of treatment for 10 weeks. This dose was chosen based on the fact that this
 age group typically consumes 10g less dietary fiber than recommended. All study measures are
 collected prior to, and after the intervention. The primary measure is abdominal pain
 frequency and intensity during 7 consecutive days. Secondary measures include parent and
 child reported anxiety and quality of life. Stool samples are used to determine gut
 microbiota and SCFAs. MRI will be used to assess the role of brain regions implicated in pain
 and anxiety. Respiratory sinus arrhythmia during seated rest will be used to assess basal
 vagal tone.
Inclusion Criteria:

 -  Diagnosis of functional abdominal pain as defined by the Rome IV criteria for
 childhood functional gastrointestinal disorders

 Exclusion Criteria:

 -  Diagnosis of inflammatory bowel disease or irritable bowel syndrome

 -  Lactose intolerance

 -  Abdominal surgery within the past year

 -  Contraindications for imaging

 -  Antibiotic use over the last 3 months