The Effects of Prebiotics on Gut Bacterial Parameters, Immune Function & Exercise-Induced Airway Inflammation.
Condition: Exercised Induced Asthma; Asthma
MeSH terms: Asthma; Asthma, Exercise-Induced; Inflammation
Study type: Interventional

Summary: 
      The current study aims to explore the role of prebiotic supplementation in adults with and
      without Asthma/Exercise-Induced Bronchoconstriction (A/EIB). All participants will be asked
      to consume a prebiotic supplement, and a placebo, each for a total duration of four weeks,
      separated by a two-week wash out period. The investigators hypothesise that improvements in
      pulmonary function observed in adults with Asthma following prebiotic supplementation. We
      hypothesise that improvements in pulmonary function will be attributed, at least in part, to
      gut microbiota mediated improvements in human immune function.
    

Detailed description: 
      The current study will investigate the effects of prebiotic supplementation on airway
      inflammation/bronchoconstriction in adults diagnosed with Asthma/Exercise-Induced
      Bronchoconstriction (A/EIB). Previous research conducted in adults diagnosed with A/EIB has
      reported significant improvements in pulmonary function following three weeks of prebiotic
      supplementation. The significant improvements in pulmonary function were attributed to an
      attenuation of various markers of airway inflammation, potentially regulated by gut
      microbiota mediated improvements in systemic immune function.

      Prebiotics are a type of non-digestible carbohydrate/dietary fibre that can only be digested
      by certain beneficial bacteria. During the fermentation of prebiotics, beneficial bacteria
      produce energy/metabolites that can be used to support a variety of human immune functions,
      such as reducing the level of airway inflammation that occurs following exposure to relevant
      triggers (e.g. exercise).

      Imbalances and/or deficiencies in gut bacterial composition/metabolic activity have been
      identified in children/adults diagnosed asthma. However, the potential mechanisms behind
      prebiotic mediated improvements in the severity of asthma have yet to be investigated.

      Participants with and without A/EIB will be allocated two separate nutritional supplements
      following a double-blind, placebo-controlled design. During the first phase of the
      nutritional intervention, participants will consume the first supplement (either prebiotic or
      placebo), for a total duration of four weeks. A two-week wash out period will then be
      completed before the remaining nutritional supplement is administered for an equal duration.

      Analyses of key human/bacterial metabolite concentrations will be carried out alongside
      assessments of immune and pulmonary function, and intestinal permeability at baseline, and
      throughout all phases of the nutritional intervention. Current understandings of the role of
      the gut microbiota in the pathogenesis of A/EIB will be expanded through the investigation of
      novel pathophysiological mechanisms, helping to inform future therapeutic prospects for
      asthma.
    

Intervention name(s): HOST-DM059; Maltodextrin
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Experimental Supplement: HOST-DM059.
Participants will be asked to orally consume one powdered sachet each day, at the same time in the morning, reconstituted in tea/coffee/fruit juice, or sprinkled over cereal etc. Whichever method of consumption is chosen, this must be kept consistent across both supplementation phases.; Placebo Comparator: Maltodextrin.
Other intervention name(s): Bimuno, B-GOS, Prebiotic, Galactooligosaccharide.; Placebo
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Intervention model description: Participants will be administered a prebiotic (galactooligosaccharide; HOST-DM059), and a taste/appearance matched placebo (Maltodextrin) in a, double-blind, placebo-controlled, crossover design.
The nutritional intervention will be completed over a twelve week period, consisting of two, four-week supplementation phases separated by a four-week wash out period. Participants will be randomly allocated one of the nutritional supplements during phase one (labelled as either 'L', or 'X'), and asked to consume one powdered sachet every morning (3.6g). Participants will then complete a four week wash out period, before being assigned the remaining nutritional supplement during phase two. Sachets can be reconstituted in tea/coffee/fruit juice, or sprinkled over cereal etc.
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Asthma; Exercise-Induced Asthma; Gut Bacteria; Bimuno® Galactooligosaccharide; Pulmonary Function; Prebiotics; Exercise-Induced Bronchoconstriction; Gut Microbiota; Nutritional Intervention; Eucapnic Voluntary Hyperpnoea; Systemic Inflammation; Systemic Immune Function; Regulatory T Cells; TH1 Cells; TH2 Cells; Short-Chain Fatty Acids; Acetate; Propionate; Butyrate; Metabolomics; Airway Inflammation; Intestinal Permeability