. The PA-19-196 Ruth L. Kirschstein National Research Service Award to Promote Diversity in Health-Related Research will provide the candidate the continued training she needs to become an independent nurse scientist. Irritable bowel syndrome (IBS) is a prevalent gastrointestinal (GI) disorder that affects >35 million Americans and health care expenditures are estimated to be >20 billion dollars. Persons with IBS experience recurrent abdominal pain accompanied with diarrhea and/or constipation. Risk factors for IBS include low-grade mucosal inflammation, altered intestinal permeability, as well as gut dysbiosis (microbial imbalance). Recently, the gut microbiome and its metabolites were identified as important factors contributing to altered brain-gut- microbiome communication. Of relevance to this application is the role of diet and its relationship to the gut microbiota and IBS symptoms. Approximately 64%-89% of the IBS population report that food is a trigger for their IBS symptoms. Current research literature supports the hypothesis that diet modifies gut microbiome and altered gut microbiota (dysbiosis) may be responsible for the initiation and maintenance of IBS symptoms. Pharmacologic and behavioral therapies are effective for only about 50% of persons with IBS. Carbohydrate restriction diets such as low Fermented Oligosaccharides Disaccharides Monosaccharides and Polyols dietary intervention has shown efficacy in some IBS patients, but have also been shown to decrease gut microbial diversity and reduce the production of short chain fatty acids (SCFAs). The primary focus for this proposal is to characterize the fecal SCFA metabolome of healthy individuals and persons with IBS in relation to diet. SCFAs are used by colon epithelial cells for energy, thus ensuring adequate resources for repair and barrier integrity. The purpose of this descriptive study is to explore the links among dietary fiber (DF) intake, 16SrDNA data, fecal SCFAs, and GI symptoms (e.g., abdominal pain, diarrhea and constipation) and to add further insights about IBS pathobiology and symptom management. The long-term goal is to provide preliminary data for the development of evidence-based personalized dietary interventions for IBS symptoms. This project will use 3-day food diary, 28-day IBS symptom diary, and 16S rDNA data, and stool samples from individuals who participated in a study by the sponsor's team (Microbiome & Abdominal Pain Study, NR014479). The novel component of this research will be the focus on SCFAs using targeted metabolomics approach in fecal samples and their relationship to daily symptoms. Stool samples from IBS (n=30) and healthy controls (n=30) will be randomly chosen and assayed at Northwest Metabolomics Research Center and assayed at Northwest Metabolomics Research Center. Funding from this NRSA grant will provide the support to complete Ms. Utleg's dissertation research project, enroll in relevant courses and participate in attending microbiome seminars and workshops, expert mentorship, and dissemination of findings.
Diet can induce morphological, structural, and biochemical changes to the gut environment by affecting bacterial composition and their metabolic activities. Studying the characteristics of complex carbohydrates intake will help elucidate the role of diet as a key risk factor in triggering of irritable bowel syndrome (IBS) symptoms and this evidence will help in the design of a more personalized, targeted nutritional intervention based on specific biochemistry profile for each person with IBS to decrease symptoms.
