Date of Award

Fall 2021

Project Type

Thesis

Program or Major

Animal and Nutritional Sciences

Degree Name

Master of Science

First Advisor

Sherman Bigornia

Second Advisor

Mahdi Garelnabi

Third Advisor

Cheryl Andam

Abstract

OBJECTIVES: To quantify the longitudinal effects of a direct SNAP-Ed intervention on diet, systemic inflammation, and gut microbiota among adult Bhutanese refugees. To measure the cross-sectional associations between dietary quality, inflammation, and gut microbial producers of short chain fatty acids (SCFA).METHODS: A convenience sample of 54 Bhutanese refugee adults (mean age=47 ± 2 years, 83% female) residing in New Hampshire was block randomized into the SNAP-Ed or control group. The SNAP-Ed intervention consisted of six one-hour nutrition lessons taught by a bi-cultural community health worker in the participants’ homes. Three 24-hour recalls were used to assess dietary intake at baseline and follow-up in both groups. Similarly, fasting blood and fecal samples were collected by a trained phlebotomist at baseline and follow-up. Adherence to the US dietary guidelines was defined using the 2015 Healthy Eating Index (HEI-2015). Fasting blood samples were analyzed for inflammatory biomarkers IL-6, TNF-α, and CRP, while fecal samples were sequenced to find bacterial abundance. Changes from baseline to follow-up in the SNAP-Ed group relative to the control group for dietary quality, inflammation, and SCFA producing microbes was quantified using repeated measures ANOVA. Cross-sectional associations between tertiles of dietary quality, inflammation, and SCFA producing microbes were quantified using ANCOVA adjusted for age, sex, and type 2 diabetes status. RESULTS: On average, participants lived in the U.S. for 7.8 ± 0.5 years, with a household size of 3.8 ± 0.2 members. The prevalence of overweight/obesity and type 2 diabetes was 82% and 41%, respectively. SNAP-Ed participants (3.4 ± 0.5 to 2.6 ± 0.7 HEI Component Score) were found to have a decrease in whole grain consumption at follow-up relative to the control (3.3 ± 0.8 to 4.1 ± 0.9, P=0.003). Otherwise, there were no significant differences in dietary quality from baseline to follow-up when comparing SNAP-Ed and control groups. In cross-sectional, multivariate adjusted models, individuals with higher HEI-2015 scores tended to have lower IL-6 levels (2.4 ± 1.2 pg/mL, 1.7 ± 1.2 pg/mL, 1.1 ± 1.2 pg/mL by increasing HEI tertile, P-trend=0.06) and higher microbial diversity (P-trend=0.06). In examining the individual HEI components, greater whole fruit consumption was inversely associated with IL-6 (P-trend=0.03) and E. hallii abundance (P=0.02). Greens and beans consumption was also inversely associated with CRP (P-trend=0.01). Higher fatty acid ratios were associated with higher abundance of C. catus, E. biforme, and P. copri (all P<0.05), while higher saturated fat intake was inversely associated with E. biforme and P. copri (both P<0.05). Higher whole grain consumption was also inversely associated with F. prausnitzii, while refined grain consumption was inversely associated with E. biforme (both P<0.05). CONCLUSIONS: The standard SNAP-Ed intervention did not appreciably improve dietary quality in a sample of 54 Bhutanese refugee adults. A number of specific food groups, particularly fruit, greens and beans, and healthy fats, showed significant associations with more favorable inflammation levels and gut microbial abundance. These associations can be used to improve and tailor the SNAP-Ed intervention to be better suited to this population. Inclusion of lessons emphasizing fruit, greens and beans, and healthy fats with culturally relevant foods could improve SNAP-Ed outcomes in the future.

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