Periodic Reporting for period 1 - FIBCOLIT (Modulation of intestinal barrier function and inflammation via butyrate-promoting dietary fibre)
Período documentado: 2021-09-01 hasta 2023-08-31
The overall aim of this study is to examine whether and how a 6-week intervention with a dietary fibre known to promote luminal butyrate production affects measures intestinal barrier function, intestinal inflammation, intestinal microbiota, and gastrointestinal symptoms in MC patients. This objective has considerable importance given that 1) the last 20 years have seen a significant global increase in the incidence and prevalence of inflammatory bowel diseases (IBD) , and 2) intestinal inflammation, even at a low grade, drives the development of systemic inflammation in obesity and obesity-related disorders, such as metabolic syndrome and type 2 diabetes. Considering the personal, societal, and economic burden of these diseases, there is a growing need for a better understanding of the physiological mechanisms that maintain and modulate intestinal homeostasis. Should DF supplementation prove effective at restoring intestinal homeostasis in MC, it could potentially offer a non-pharmaceutical option to disease prevention and management as well as reveal new insights about the pathophysiological mechanisms that promote intestinal inflammation.
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.