Date of Award

9-1-2025

Degree Type

Thesis

Degree Name

Master of Food and Animal Sciences (M.S.)

Department

Agricultural and Environmental Sciences

First Advisor

Gajender Aleti

Abstract

Obesity remains a major global health concern, contributing significantly to chronic diseases. While diet is a well-known driver of obesity, emerging evidence suggests the key role of gut microbiota in mediating diet-related metabolic outcomes. Numerous epidemiological and microbiome studies suggested diet-microbiome-obesity associations. However, consistent microbial markers and mechanistic insights remain limited. To address this gap, this study aimed to identify consistent microbial species associated with obesity and investigate how diet influences their growth and function. A review of over 200 publicly available 16S rRNA and shotgun metagenomic studies revealed consistent microbial patterns in obesity, including members of Firmicutes and Bacteroidetes. To test functional relevance, we cultured obesity-associated bacterial isolates in media simulating traditional (high-fiber) and western (high-fat, low-fiber) diets. Traditional diets supported the growth of potentially beneficial microbes, while western diets enriched obesity-associated microbes. Culture supernatants were further tested on adipocyte cell models. Remarkably, the same bacterial strains exhibited opposing effects depending on the growth medium. Metabolites from bacteria grown in western diet media increased lipid accumulation, whereas those grown under fiber-rich conditions exhibited anti-adipogenic or neutral effects. These findings demonstrate that dietary composition not only alters microbial growth but also modulates microbial function and metabolite production, influencing host adipogenesis. These findings highlight the potential of diet to shape microbiota-driven metabolic outcomes and support microbiome-targeted dietary strategies for obesity prevention and management. Also, lay the groundwork for developing next-generation probiotics and dietary interventions that harness beneficial microbial functions to combat obesity and improve metabolic health.

Download

Included in

Food Science Commons

Share

COinS