Master of Science, The Ohio State University, 2020, Health and Rehabilitation Sciences

Introduction: Irritable bowel syndrome (IBS) is the most commonly diagnosed functional gastrointestinal disorder (FGID) defined by characteristics of abdominal pain related to defecation and altered bowel habits. Poor efficacy of medical treatment and reports of dietary factors impacting gastrointestinal symptoms has led to dietary interventions being at the forefront of research. Hypotheses suggest consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) are the primary culprits of symptom induction in this population. Based on these hypotheses, the low FODMAP diet (LFD) was developed to target gastrointestinal symptoms which has shown efficacy in nearly 75% of sufferers.1 The LFD requires complete exclusion of high FODMAP food items which excludes many nutrient-dense food groups such as fruits, vegetables, and whole grains. Due to this restrictive approach, investigation of a more liberal dietary approach is warranted. Objectives: To assess compliance and nutritional adequacy of the LFD compared to an individualized dietary approach based on the Dietary Guidelines for Americans (DGAs) optimizing dietary fiber and minimizing added sugar intake. Methods: A case presentation of four subjects following either a LFD or individualized dietary approach tailored from the Dietary Guidelines for Americans were assessed for dietary compliance and nutritional adequacy to gain insight into challenges of dietary interventions in those with IBS. Subjects diagnosed with IBS were randomized to either an individualized diet based on the DGAs focused on modulation of added sugar and dietary fiber, or the LFD. Nutrient analysis, using the Nutrition Data System for Research (NDSR) reported changes in nutrient intakes after the intervention. Results: The first four consented subjects were randomized to an individualized dietary approach (n=2) or the LFD (n=2) are presented. Macro- and micronutrient intake data was highly vari (open full item for complete abstract)

Committee: Kristen Roberts Dr. (Advisor); Marcia Nahikian-Nelms Dr. (Committee Member); Jill Clutter Dr. (Committee Member) Subjects: Nutrition

Master of Science, The Ohio State University, 2019, Allied Medicine

Irritable bowel syndrome (IBS) is the most common diagnosis made among gastroenterologists in the United States. Patients correlate their symptoms with the ingestion of food. A low fermentable oligosaccharides, disaccharides, and polyols (FODMAP) diet is effective at controlling symptoms, but limited evidence has prevented the development of standard clinical guidelines for implementation. Nutritional adequacy of the low FODMAP diet is a concern due to the diet's restrictive nature. Two weeks appears to be the shortest duration of the diet necessary for symptom relief, yet dietary compliance reporting is lacking in the literature. This study aimed to 1) assess the efficacy of a 2-week low FODMAP diet elimination phase, 2) describe the nutritional adequacy of the low FODMAP diet and differences in dietary intake before and after initiation of the diet, and 3) describe dietary compliance during the two-week intervention of the low FODMAP diet and its relationship to symptom relief. Fifty-nine participants with IBS attended a low FODMAP group education class taught by trained registered dietitian nutritionists. At baseline and week 2 (end of study), participants completed the IBS-Severity Scoring System (IBS-SSS), Bristol Stool Form Scale, and three 24-hour diet recalls. Compliance was assessed through daily high FODMAP food checklists. ESHA Food Processor was used to analyze dietary data. Results were reported using descriptive statistics and the relationship between adherence and symptom improvement was assessed via a Pearson's correlation. A total of 20 subjects enrolled in the study and 6 (30%) completed the intervention. There was a 70% drop out rate (n=14). By week 2, all 6 who completed the study were responders to the low FODMAP diet (a reduction of ≥50 points on the IBS-SSS) and dropped at least one symptom severity level. At baseline, median dietary intake of calcium, potassium, iron, vitamin D, and fiber were all below the recommended dietary allowance (RD (open full item for complete abstract)

Committee: Kristen Roberts PhD, RDN (Advisor); Marcia Nahikian-Nelms PhD, RDN, FAND (Committee Member); Jill Clutter PhD, MCHES (Committee Member) Subjects: Nutrition

Master of Science, The Ohio State University, 2017, Allied Medicine

Ingestion of food has been widely documented to trigger symptoms of Irritable Bowel Syndrome (IBS)1. In recent years, the low FODMAP diet has been gaining high-quality evidence of efficacy in controlling symptoms of IBS.2 The diet eliminates foods high in poorly absorbed carbohydrates including fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) for a period of 2-8 weeks, followed by planned systematic re-introduction to assess tolerance.2 However, this novel therapy remains in need of further research to form a sound evidence-based application strategy. Of concern is the diet's nutritional adequacy given its highly restrictive nature and lengthy elimination period. This pilot study assessed changes in nutrient intake following initiation of the diet, and examined diet adequacy in view of the recommended dietary allowance (RDA) of nutrients. Five patients with severe to moderate IBS were enrolled. After collection of a health questionnaire, an IBS-SSS, a Bristol Stool Form Scale, and a 3-day diet record, subjects attended a nutrition education class on the low FODMAP diet and were asked to follow it for 6 weeks. On week two of the diet, subjects filled another 3-day diet record. Results showed that in the majority of subjects, total caloric intake fell within estimated needs. While percent of total calories from fat remained stable, percent of total calories from protein decreased but remained within the acceptable macronutrient distribution range. Percent of total calories from carbohydrates increased, but remained below acceptable range- similar to pre-study status. Intake of vitamin D, calcium, and folate decreased, while intake of vitamin C, iron and fiber increased. However, these micronutrients were all at levels below RDA. Our findings agree with reported lower intakes of protein and calcium, and stable intake of fiber in those following the diet. However, our results differ from findings of lower caloric and carbohydrate con (open full item for complete abstract)

Committee: Marcia Nahikian-Nelms (Advisor); Kristen Roberts (Committee Member); Jill Clutter (Committee Member) Subjects: Health; Health Care; Health Education; Health Sciences; Medicine; Nutrition

Master of Science, The Ohio State University, 2017, Allied Medicine

Background: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder that affects patients worldwide. A diet low in fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) has shown to improve symptoms of a majority of patients with IBS. Current literature is insufficient to provide guidelines for how long patients should follow the elimination phase of the diet. Methods: Patients attended a low FODMAP diet education class and were followed for six weeks. Every two weeks, patients completed the validated IBS-Symptom Severity Scale questionnaire. Patients also completed checklists of all high FODMAP foods consumed daily, to measure adherence. Results: Five patients participated in this study. By week two, all 5 patients had composite symptom scores classified at least one severity level lower than baseline. By week six, 1 patient's symptoms had returned to baseline severity classification, indicating an 80% response rate overall. Patients were non-adherent to the diet on 24/210 total patient days (11.4%). Adherence was directly related to symptom severity. Conclusion: Some patients may benefit from a shortened elimination phase of the low FODMAP diet, while some may require the full six weeks for best effect. Adherence to the diet ensures likelihood of symptom improvement.

Committee: Marcia Nahikian-Nelms (Advisor); Kristen Roberts (Committee Member); Jill Clutter (Committee Member) Subjects: Nutrition

Master of Science (MS), Wright State University, 2011, Biochemistry and Molecular Biology

The human-associated microbiota has been the focus of much current research, with the microbiota inhabiting the gastrointestinal tract of particular interest. These organisms play many roles in human health and well-being. However, shifts in the composition of the intestinal microbiota have been associated with diseases such as irritable bowel syndrome, inflammatory bowel disease, and colon cancer. Several recent studies have reported on the distal gut microbiota composition of healthy adults and those with IBS, while there is a lack of studies devoted to adolescents. This study utilized a custom-designed Affymetrix Microbiota Array capable of detecting 775 phylo-species of intestinal bacteria to determine the composition of the distal gut microbiota of 22 adolescents suffering from IBS-D (diarrhea-predominant) and 22 healthy adolescents. High sample-to-sample variation was observed in both groups at genus level. While some differences were observed in mean relative abundance of several bacterial genera between IBS-D and healthy adolescents, including Bifidobacterium, Lactobacillus, Veillonella, and Prevotella, these differences were not significant. Sample groups also failed to separate in PCA space. Therefore, we cannot conclude that the distal gut microbiota of adolescents with IBS-D is significantly different than that of healthy adolescents.

Committee: Oleg Paliy PhD (Advisor); Michael Markey PhD (Committee Member); Nicholas Reo PhD (Committee Member) Subjects: Microbiology; Molecular Biology

PhD, University of Cincinnati, 2011, Medicine: Epidemiology (Environmental Health)

Introduction: Acute gastroenteritis (GE) is an important cause of morbidity and mortality worldwide, particularly for children. Several studies have associated GE, which may have a foodborne etiology, with the development of irritable bowel syndrome (IBS). Understanding the incidence of GE, and its association with IBS and functional bowel disease (FBD), will improve the clinical management of patients and provide policy makers with better burden of disease estimates. Aims: The aim of this prospective cohort study is to estimate the incidence of GE, IBS and FBD, estimate the relative risk of IBS one year post-GE and explore potential risk factors for IBS among primary care practices in the Netherlands from 1998 to 2009. Methods: Data from the Primary Care Network Utrecht (PCNU), a prospective cohort with routine consultation data for more than 60,000 patients annually, were used for the analysis. The annual incidence of GE and IBS consultations were estimated and temporal trends were evaluated. Patients, aged 18 to 70 years, with gastrointestinal infection or diarrhea and at least one year of data recorded in the PCNU electronic databases were included in the GE cohort. Patients with a history of cancer, alcohol abuse, GE symptoms in the prior 12 months, pre-existing IBS/FBD diagnosis or abdominal surgery or 5 or more prescriptions associated with IBS or FBD treatment were excluded. Patients consulting for non-IBS related medical reasons, matched by age, gender, consulting practice and time of visit, were randomly selected for the control cohort. The prevalence of IBS during follow-up was compared in the GE and control cohort. Results: In total, 23,451 patients consulted their physician for at least one GE-related event between 1998 and 2009. During the same time period, 4,980 patients consulted the PCNU for IBS. Temporal trends were fairly consistent across health outcomes with a decreasing trend in incidence from 1998 to 2005, at which point the trend reversed a (open full item for complete abstract)

Committee: Paul Succop PhD (Committee Chair); Arie Havelaar PhD (Committee Member); Craig Hedberg PhD (Committee Member); Stephen Kralovic MD (Committee Member) Subjects: Epidemiology