PROJECT SUMMARY/ABSTRACT.
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.
