Topical Area: Nutritional Microbiology, Nutrient-Gene Interactions
Objectives : The links between food, gastrointestinal (GI) function and comfort, and mental well-being are at the forefront of nutritional research. Irritable Bowel Syndrome (IBS) is a functional GI disorder and the combination of detailed patient reported outcomes (PROs) combined with omic data could better define these disorders.
Methods : The Christchurch COMFORT cohort is a case-control study: 337 participants with functional GI disorders (functional constipation FC, functional diarrhoea FD, IBS constipation IBS-C, IBS diarrhoea IBS-D) and asymptomatic controls. Demographics, symptom scores, psychological scores and dietary intake were recorded using the ‘Modified Hunter New England’ (Rome IV diagnostic criteria questionnaires; Medical History Questions; Hospital Anxiety and Depression Scale, HADS). Demographics included Structured Assessment of Gastrointestinal Symptoms (SAGIS); and Diet Diary and Live Symptoms Score (FAST) along with PRO Measurement Information System (PROMIS). Biological samples collected for an untargeted LCMS analysis of plasma and shot-gun metagenome analysis of faecal DNA. Ethical approval was obtained from the University of Otago Human Ethics Committee (H16/094).
Results : Symptom questionnaires were able to cluster 287 subjects into: IBS (42%), functional disorders (18%) and healthy controls (40%). Within IBS, 46% were IBS-D, 23% were IBS-C and 31% were IBS-M. Severity scores were higher for all IBS cases with PROMIS-GI scales. A higher score of health worry was reported in IBS-C than other IBS subtypes. HADS anxiety and depression scales were higher in IBS cases (vs. healthy controls). The FAST diary symptoms correlated with PROMIS GI scales (exception for constipation). Metabolomic analyses detected differential plasma metabolites and pathways (bile acids, lipids, specific amino acids) affected between IBS-C+FC vs IBS-D+FD, healthy vs IBS-D and healthy vs IBS-C. Metagenomics suggests that carbohydrate, methane, and sulfur metabolism may be important in IBS.
Conclusions : These data will allow us to apply a systems biology approach to identify key pathways and correlate them with the questionnaire data to better understand functional GI disorders.
Funding Sources : Funded by the NZ National Science Challenge High-Value Nutrition programme.
Science Team Leader, Food Nutrition & health
science Team Leader
Plant and Food research
Academic Head, Department of Medicine
University of Otago