Graduation Semester and Year
Summer 2026
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Quantitative Biology
Department
Biology
First Advisor
Dr. Woo-Suk Chang
Second Advisor
Dr. Todd Castoe
Third Advisor
Dr. Jeffrey Demuth
Fourth Advisor
Dr. Dylan Parks
Fifth Advisor
Dr. Qing Tang
Abstract
Fermented soybean products (FSPs) contain soybean-derived substrates, fermentation-associated microorganisms, and bioactive compounds that may interact with the human gut microbiome and host physiology. However, despite the growing interest in FSPs, longitudinal human studies specifically evaluating traditional Korean-FSPs (K-FSPs), particularly among United States-based populations, remain limited. The objective of this work was to evaluate the effects of three K-FSPs, including Cheonggukjang, Gochujang, and Doenjang, on host physiological responses, gut microbial community structure, predicted microbial functional potential, and fecal butyrate responses in healthy adults. Three independent dietary intervention cohorts were conducted using FSP formulations produced either by traditional artisan methods (Product A) or by industrial manufacturing (Product B). Participants consumed 3 g per day of the assigned product, and longitudinal fecal samples, host physiological measurements, and anthropometric measurements were collected. Gut microbiome responses were evaluated using 16S rRNA gene sequencing, taxonomic composition, alpha diversity, and beta diversity analyses. Additional functional and metabolite-focused analyses included PICRUSt2-predicted functional profiling, microbial co-occurrence network analysis, and targeted fecal butyrate measurement in selected Cheonggukjang samples. Across interventions, consumption of the FSPs did not produce broad physiological or microbial disruption in healthy adults. Most host biomarkers remained within clinical reference ranges, supporting overall tolerability. Microbial composition and alpha diversity were broadly maintained, while beta diversity, predicted functional profiles, and network-based analyses revealed more subtle product- and host-associated variation. Measured fecal butyrate did not consistently correspond with individual putative butyrate-associated taxa, suggesting that metabolite output reflects community-level microbial activity, cross-feeding, utilization, host absorption, and fecal excretion rather than taxa abundance alone. Overall, consumption of the K-FSPs was generally well tolerated and was associated with subtle, individualized, and product-dependent host-microbiome responses within a largely stable physiological and microbial system.
Keywords
Human gut microbiome, Fermented soybean products, Cheonggukjang, Gochujang, Doenjang, 16S rRNA gene sequencing, Alpha diversity, Beta diversity, PICRUSt2, Butyrate
Disciplines
Bioinformatics | Environmental Microbiology and Microbial Ecology | Food Microbiology | Human and Clinical Nutrition | Microbiology | Nutrition
License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Moncier, Shannon, "Effects of Fermented Soybean Products on the Human Gut Microbiome, Microbial Metabolism, and Host Physiology" (2026). Biology Dissertations. 5.
https://mavmatrix.uta.edu/biology_dissertations2/5
Included in
Bioinformatics Commons, Environmental Microbiology and Microbial Ecology Commons, Food Microbiology Commons, Human and Clinical Nutrition Commons
Comments
Acknowledgments: The author gratefully acknowledges the Microbiome Innovation and Functional Imaging (MIFI) Core Facility and the UTA Health Services Center for their support of this research.