Fiber-rich Foods, Weight Status, and the Gut Microbiota in NH Hispanic Adults at Risk for Food Insecurity

Study Overview
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Brief Summary
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This study will include a group of 60 Hispanic adults living in New Hampshire with or without overweight/obesity. The study aims to assess food access and intake of fiber-rich foods, characterize fecal microbiota composition, and assess the relationship between the intake of fiber-rich foods and components of the gut microbiota-gut-brain axis. These aims will be accomplished through biospecimen collection including a pre-collected stool sample, a fasting blood sample, and a Mixed Meal Tolerance Test (MMTT). In addition, participants will answer questionnaires on dietary intake, food insecurity and access, physical activity, eating behavior, and sociodemographic characteristics.

Detailed Description
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This study will include Hispanic adults living in New Hampshire with or without overweight/obesity. In a group of 60 participants, the study aims to assess food access and intake of fiber-rich foods, characterize fecal microbiota composition, and assess the relationship between the intake of fiber-rich foods and components of the gut microbiota-gut-brain axis. The study involves biospecimen collection including a pre-collected stool sample, a fasting blood sample, and a Mixed Meal Tolerance Test (MMTT). In addition, participants will answer questionnaires on dietary intake, food insecurity and access, physical activity, eating behavior, and sociodemographic characteristics. Pre-collected stool samples will be obtained from participants. Anthropometric measurements will be collected at the time of the study visit including height, weight, and waist and hip circumference. BMI will be calculated. An intra-venous catheter will be inserted by a healthcare professional to first collect a fasting blood sample, and will remain inserted for all following blood samples. Subjects will then undergo a Mixed Meal Tolerance Test (MMTT), a validated metabolic assessment in which the participant ingests a liquid mixed meal (e.g., Boost or Ensure), and blood samples are subsequently collected 15min, 30min, 60min and 120min after meal ingestion. In the intervals between blood sample collections, subjects will complete questionnaires on dietary intake, food insecurity and access, physical activity, eating behavior, and sociodemographic characteristics. The following validated measures will be used to assess these aims: USDA Household Food Sufficiency Questionnaire Perceived Nutrition Environment Measurements Survey (NEMS-P) Shortened version of the Three Factor Eating Questionnaire Latino Dietary Behaviors Questionnaire (LDBQ) Global Physical Activity Questionnaire Short Acculturation Scale for Hispanics NHANES Weight History Questionnaire Medical History Questionnaire

Official Title
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Fiber-rich Foods, Weight Status, and the Gut Microbiota: A Comparative Study in NH Hispanic Adults at Risk for Food Insecurity

Conditions
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Food Insecurity, Overweight and Obesity

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Two groups of participants will be recruited: Healthy BMI (20-25 kg/m2, n=30), and Overweight/Obese BMI (>28 kg/m2, n=30) Other inclusion criteria are as follows: Adult men and women (18-55 years of age) residing in a SNAP-eligible households; Self-identifying as Hispanic or Latino, and with origin or cultural background from a Spanish-speaking Latin American country; Willingness and ability to provide a signed informed consent; and Willingness to complete study visits and participate in all aspects of the study. Exclusion Criteria: Adults reporting any of the following conditions will be excluded from the study: Diagnosed type 2 diabetes, chronic kidney or liver disease, cancer, chronic gastrointestinal conditions, cognitive impairment or incapacitating mental health problems, lack of mobility and physical independence, self-reported weight loss >5 kg within past 6 months, history of communicable or chronic diseases, medication use or surgery that would preclude safe and active study participation, bariatric surgery, antibiotic use within past 3 months, ongoing participation in other clinical trials, use of anti-obesity medications within the past year, inability to communicate in oral and written form in English and/or Spanish, and habitual consumption of more than two alcoholic drinks per day or of illegal drugs.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy BMI (20-25 kg/m2, n=30)<br>A group of 30 Hispanic/Latino adults who are NH residents residing in SNAP-eligible households, and have a BMI between 20 and 25 kg/m2. | |
| Overweight/Obese BMI (>28 kg/m2, n=30)<br>A group of 30 Hispanic/Latino adults who are NH residents residing in SNAP-eligible households, and have a BMI greater than or equal to 28 kg/m2. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Food Insecurity and Access | Food insecurity scores will be generated at the household and individual level. Objective measures of food environment and access will be calculated using a modified version of the Retail Food environment Index (RFEI) that focuses on government assistance food sources within a radius around individuals' residential address (e.g., pantries, stores selling fresh food, SNAP retailers). Perceived food environment and access scores will be obtained from the NEMS-P. This questionnaire includes questions about food purchasing habits, priorities for food purchasing choices, characteristics of the local food environment including food availability at retailers and vendors, and food availability at home. | August 2022 to August 2023 | 
| Fiber Intake | Fiber intake will be calculated using validated analytical pipelines of the NHANES DSQ, developed at the National Cancer Institute. This methodology will be used to calculate predicted daily intakes of total fiber. The PI has previously used this methodology with Hispanic older adults. A comprehensive list of specific fiber-rich foods routinely consumed will be compiled, which will enable the identification of opportunities to increase local fiber-rich food production and consumption by highlighting foods commonly consumed by NH Hispanics (or gaps in current diets that could be fulfilled with local foods). | August 2022 to August 2023 | 
| Microbial Richness | Microbial richness (number of different taxonomic groups per sample) will be established using Dirichlet multinomial mixtures. Relative abundance of bacterial groups (e.g., at the species, genus, phylum level) will also be calculated. | August 2022 to August 2023 | 
| Short-Chain Fatty Acids | The SCFA assessment will focus on total SCFA, butyrate, acetate, and propionate. SCFA analysis will be measured using gas chromatography coupled with flame ionization detection. | August 2022 to August 2023 | 
| LPS | The concentration of lipopolysaccharides (LPS) in the blood, a measure of gut permeability, will be measured. High circulating LPS, known as metabolic endotoxemia, is associated with insulin resistance, obesity, and other metabolic complications. | August 2022 to August 2023 | 
| Insulin | Insulin levels will be measured using an enzyme-linked immunoassay (ELISA). The levels will be measured both from a fasting blood sample, and during MMTT. The fasting level will be used to for the calculation of the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). | August 2022 to August 2023 | 
| Glucose | Fasting glucose level will be used to for the calculation of the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). | August 2022 to August 2023 | 
| GLP-1 | The levels of GLP-1 will be measured using an enzyme-linked immunoassay (ELISA). The levels of this hormone will be measured both from a fasting blood sample, and during MMTT. | August 2022 to August 2023 | 
| Ghrelin | The levels of ghrelin will be measured using an enzyme-linked immunoassay (ELISA). The levels of this hormone will be measured both from a fasting blood sample, and during MMTT. | August 2022 to August 2023 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fruit, Vegetable, and Whole Grain Intake | Fruit, vegetable, and whole grain intake will be calculated using validated analytical pipelines of the NHANES DSQ, developed at the National Cancer Institute. These methodologies will be used to calculate predicted daily intakes of servings of fruits, vegetables, vegetables including legumes, and whole grains. | August 2022 to August 2023 | 
| Enterotype Classification of Gut Microbiota | Individual enterotype classification of gut microbiota, a measure of the dominant taxonomic groups per individual, will be established using Dirichlet multinomial mixtures. | August 2022 to August 2023 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Overweight, Obesity, Food insecurity, Hispanic/Latino, Gut microbiome