
Theses and Dissertations
Advisor
Shecoya, White
Committee Member
Komakech, Joel
Committee Member
Mlsna, Todd
Committee Member
Cheng, Wen-Hsing
Date of Degree
8-7-2025
Original embargo terms
Immediate Worldwide Access
Document Type
Dissertation - Open Access
Major
Food Science, Nutrition, and Health Promotion
Degree Name
Doctor of Philosophy (Ph.D.)
College
College of Agriculture and Life Sciences
Department
Department of Biochemistry, Nutrition and Health Promotion
Abstract
Selenoprotein H (SELENOH) is an oxidoreductase located in the nucleolus, and its biochemical levels decrease with selenium (Se) deficiency, as reported in mammalian research. This current investigation aimed to understand the impact of nutritional Se deficiency on gut microbial composition and metabolomic profiles. The Firmicutes/Bacteroidota (F/B) ratio, linked to various health conditions, was balanced for wildtype (WT) mice (1.06). In contrast, selenoh knockout (KO) mice associated with dietary Se deprivation had a significantly (p < 0.002) lower ratio (0.56), suggesting dysbiosis. It is believed that SELENOH levels decreased due to the Se deficient diet, and the selenoh KO mice exhibited alterations in microbial community composition and metabolite profiles, as supported by correlative analyses. With respect to the bacterial communities, significant differences between diets occurred for three taxa, including Akkemansia mucinphila, Bacteroides caecimuris, and Parabacteroides goldsteinii. Candida tropicalis, Malassezia restricta, and Cyberlindnera jadinii were three abundant fungal yeasts. Only Cyberlindnera jadinii exhibited significantly greater relative abundance between genotypes and was more abundant in the selenoh KO versus WT mice. Correlation analyses between bacterial and fungal taxa revealed both positive and negative relationships, but no specific trends were observed. The liver and serum metabolomic data contained similar amino acids, lipids, proteins, and carbohydrates. Using NMR spectroscopy, 112 liver metabolites were detected, while GC-TOF-MS analysis of the serum revealed the presence of 172, comprising both polar and nonpolar compounds. The metabolite levels varied significantly when analyzed using multivariate models such as PCA and PLS-DA (VIP scores), particularly for glucose, taurine, lactate, and UDP-glucose, which are associated with energy production and cellular health. Overall, the Se deficient diet had the most significant impact on the microbial community structure and the concentration of key metabolites within liver tissues and serum. Correlation analyses conducted across studies revealed significant linear relationships between metabolites and the microbiome. However, these differences were associated with bacterial and fungal taxa containing low relative abundances. Based on these findings, further investigation into the impact of SELENOH homeostasis on microbial and metabolite profiles should be conducted using selenoh KO mice under various nutritional Se dietary levels.
Recommended Citation
Baird, Richard Eugene, "Integrated analysis of untargeted liver, serum metabolome and gut microbiome following selenium deficiency diet in selenoh knockout and wildtype mice" (2025). Theses and Dissertations. 6612.
https://scholarsjunction.msstate.edu/td/6612