Effects of Dietary Fibre in Irritable Bowel Syndrome (IBS)
Condition: Irritable Bowel Syndrome
MeSH terms: Irritable Bowel Syndrome; Syndrome
Study type: Interventional

Summary: 
      The aim of the study is to investigate how different dietary fibre combinations affects
      physiological and microbiological outcomes, in addition to symptoms in those with IBS. The
      study will also explore the differences in responses between different fibres in different
      sub-types of IBS (e.g. constipation-predominant, diarrhoea-predominant and mixed).
    

Detailed description: 
      Currently, national and international guidelines are based upon trials of dietary fibre in
      IBS symptoms that report opposing effects. For this reason, recommendations regarding dietary
      fibre food supplementation in IBS are often conflicting. Indeed, the confusion surrounding
      dietary fibre recommendations in IBS is a consequence of the limited understanding of the
      different types of dietary fibres used, their physiology and their functions in different
      sub-groups of IBS.

      Different fibres have different characteristics (e.g. solubility, viscosity and
      fermentability) which drive different functionalities (stool forming, fermentation) in the
      gastrointestinal tract, yet it is currently unknown whether administration of dietary fibre
      combinations will result in symptomatic improvement in people with IBS.

      Participants will be randomised to one of three parallel arms for a duration of 8 weeks.

      The study will consist of 4 visits in total. The first visit will involve taking consent and
      assessing eligibility. Participants will complete the Rome IV diagnostic criteria as part of
      their eligibility assessment. Participants will be asked to complete a food and symptom diary
      for the next 7 days. Diary data will be used to confirm frequency and severity of IBS
      symptoms and ensure there is no discrepancy between participant report on the Rome IV
      diagnostic criteria.

      Visit 2: Baseline (approx 1.5 hours). Height and weight will be recorded. Participants will
      complete 7 questionnaires, provide a stool sample, a blood sample and will ingest the
      SmartPill (wireless motility capsule). Participants will blinded to the intervention and will
      be provided with sachets containing either fibre 1 (combined fibres), fibre 2 (natural
      fibres) or placebo to consume over an 8-week period.

      Visit 3: Mid-point (approx 1 hour). Participants will complete 5 questionnaires and provide a
      stool sample.

      Visit 4: Endpoint (approx 1.5 hours). Height and weight will be recorded. Participants will
      complete 7 questionnaires, provide a stool sample, a blood sample and will ingest the
      SmartPill (wireless motility capsule).
    

Intervention name(s): Fibre 1 (combined fibres); Fibre 2 (natural fibres); Dietary Supplement: placebo
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): Dietary fibre supplement; Dietary fibre supplement; Dietary supplement
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: multi-centre, 3 treatment, placebo-controlled trial
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: dietary fibre