To reach the project aims, we set up a single-centre, randomised, double-blinded, placebo-controlled intervention clinical study with a parallel design and two study arms. Patients with a confirmed diagnosis of microscopis colitis were recruited to trial and randomised to receive either a dietary fibre supplement or a placebo supplement. Both supplements were added to the participants' habitual diet as a powder (2 * 12 g per day for 6 weeks). Biological samples (blood, faecal, urine) were collected as baseline and after the intervention period. The participants were also asked to fill out specific questionnaires about the symptoms, mental health, and general well-being.
Intestinal barrier function was assessed in vivo by a standardised, non-invasive multi-sugar test that simultaneously measures gastroduodenal, small intestinal, colonic, and whole gut permeability. The test is based on the urinary excretion of five different ingested sugar probes: sucrose, rhamnose, lactulose, sucralose, and erythritol. The concentrations of these sugars are analysed by high-pressure liquid chromatography (HPLC) in urine samples collected over 24 h. Intestinal barrier function was also assessed using indirect markers from blood, namely lipopolysaccharide-binding protein (LBP) and intestinal fatty-acid binding protein (I-FABP).
The effects on inflammatory parameters were studied extensively by utilizing commercially available multiplex assays. Overall, we analysed the serum concentrations of 30 individual inflammatory parameters consisting of proinflammatory cytokines, anti-inflammatory cytokines, and chemokines. Furthermore, to examine changes in the degree of intestinal inflammation, we analysed the levels of faecal calprotectin.
The composition of intestinal microbiota before and after the intervention was assessed via shotgun metagenomics sequencing. This work was carried out by Clinical Genomics Örebro.
The effects on the patients’ symptoms, overall quality of life, and well-being were analysed by a series of validated questionnaires. The patients were asked to fill out a total of four questionnaires at baseline and after the intervention: the Gastrointestinal Symptom Rating Scale (GSRS), the Hospital Anxiety and Depression Scale (HADS), the EuroQul questionnaire, and the Short Health Scale (SHS). In addition, the patients were asked to keep a daily diary about their bowel habits (frequency and consistency) throughout the intervention period. The overall scores from each questionnaire were calculated to measure any possible changes in gastrointestinal symptom severity (GSRS), anxiety (HADS-A), depression (HADS-D), overall quality of life (EuroQul), and disease-related well-being (SHS).
Overall, the dietary fibre supplementation did not affect the patients' intestinal barrier function, markers of inflammation, and disease symptoms compared to the placebo supplementation. Due to delays in patient recruitment which has delayed the sample analyses, we are still performing comprehensive statistical analyses. These analyses will include the integration of the measured variables to create one of the most comprehensive datasets on microscopic colitis patient cohort.
The delays in patient recruitment has also delayed the project result dissemination. So far, the project results have been presented at one national and one international congress. The project results will also be presented at an upcoming European conference. The project results will be published as scientific publications when full data analyses have been completed.
