Publication Date
2025
Document Type
Dissertation/Thesis
First Advisor
Singh, Pallavi
Degree Name
Ph.D. (Doctor of Philosophy)
Legacy Department
Department of Biological Sciences
Abstract
Human health can be impacted considerably by subjective feelings of loneliness, resulting in mental illness and the dysregulation of normal cardiovascular, immune and endocrine functioning. This occurs because social isolation serves as a form of chronic stress for social mammals, spurring physiological responses akin to those associated with more standard forms of stress. On account of their highly social nature, prairie voles (Microtus ochrogaster) subsequently have become one of the model organisms of choice for investigating the effects of social isolation on the development of disease in social mammals.
This dissertation seeks to expand the scientific community’s understanding of the effects of social isolation on gastrointestinal and metabolic health, as well as the compositions of the gut microbiome, in social mammals. To do this, a comprehensive review of the limited, but valuable, body of peer-reviewed publications pertaining to the prairie vole gastrointestinal system, microbiome, and metabolome was produced. Furthermore, two original experiments were performed to examine the impact of social isolation on the microbiome and metabolome of prairie voles.
The first of these experiments examined the impact of four weeks of isolation on the behavior, gut microbiome, and gut and serum metabolomes of female prairie voles. In addition to replicating established patterns of behavior associated with anxiety and depression in socially isolated prairie voles, this work suggested isolated animals may have been developing serum metabolite profiles associated with pre-diabetes or type-two diabetes, as well as changes in gut communities indicative of poor health.
There were concerns, however, that this work suffered from certain limitations related to the number of animals utilized, the collection procedures implemented, and the duration of isolation. Hence, a second experiment was performed with a greater number of animals, a longer period of isolation, and attempts to address methodological concerns from the first experiment. Furthermore, this second experiment expanded the scope of the first by including both female and male prairie voles and assessing the neural metabolite profiles of a subset of animals.
Although the findings of the first experiment pertaining to specific metabolites and bacterial taxa were not replicated, this second experiment did reveal isolated female prairie voles to have distinct serum metabolite profiles when compared to pair-housed animals, as well as isolated males. Most notably, one metabolite found to be elevated in isolated females indicated these animals were experiencing greater levels of cellular stress.
Collectively, it is the hope of the author that the literature review and two experiments detailed in this dissertation help lay the groundwork for future research on the the impact of social isolation on the gastrointestinal system, microbiome, and metabolome of social mammals.
Some supplementary information has been uploaded in supplementary files. Supplemental File 1 contains information pertaining to the forward primers used in the study detailed in in Chapter IV. Supplemental Files 2-4 contains results of statistical analyses performed in the study detailed in Chapter IV. Supplemental File 2 contains the results of analyses comparing metabolite concentrations found in isolated males, isolated females, paired females, and paired males. Supplemental File 3 contains the results of analyses comparing metabolite concentrations found in males and females. Supplemental File 4 contains the results of analyses comparing metabolite concentrations found in isolated and paired animals.
Recommended Citation
Nuccio, Daniel Adam, "An Exploration of Social Isolation’s Effects on the Gastrointestinal and Metabolic Health of a Social Mammal" (2025). Graduate Research Theses & Dissertations. 8172.
https://huskiecommons.lib.niu.edu/allgraduate-thesesdissertations/8172
supplemental_file_2.xlsx (6 kB)
supplemental_file_3.xlsx (10 kB)
supplemental_file_4.xlsx (6 kB)
Extent
160 pages
Language
en
Publisher
Northern Illinois University
Rights Statement
In Copyright
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.
Media Type
Text
Included in
Bioinformatics Commons, Biology Commons, Microbiology Commons
