Thesis (Ph. D.)--University of Virginia, 2006. / Includes bibliographical references. Also available online through Digital Dissertations.

Ball State University LibrariesLibrary services and resources for knowledge buildingMasters ThesesThere is no abstract available for this thesis.

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 231 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Typescript (photocopy) / 154 leaves, [15] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Human Physiology, University of Adelaide, 1982

Thesis (Ph. D.)--Case Western Reserve University, 2007. / [School of Medicine] Department of Neurosciences. Includes bibliographical references.

Thesis (Ph.D.) Dept. of Human Physiology, University of Adelaide, 1982. / Typescript (photocopy).

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 105-114).

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains vii, 218 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

This study aimed to isolate and characterize in-vitro and under simulated colonic conditions, probiotic candidates isolated from food environment producing γ-aminobutyric acid (GABA), a major inhibitory neuromediator of the enteric nervous system with a potential role in modulating the immune system in many health disorders. Several lactic acid bacteria were isolated and detected for the presence of the gadB gene using PCR and GAD enzymatic assay. The most active strains with high and fast production kinetics were identified, characterized, and included Streptococcus thermophilus, Lactiplantibacillus plantarum, and Lactobacillus delbrueckii subsp. bulgaricus. The biological safety (i.e., sensitivity to antibiotics and the presence of virulence factors) and probiotic potential (i.e., resistance to gastrointestinal conditions and whole-genome sequencing) of identified bioactive strains was also confirmed in vitro. The growth, GABA production, and competitiveness of selected probiotic candidates (B. animalis, S. thermophilus, and L. bulgaricus) were investigated in the presence of human gut microbiota ex vivo in a model of a proximal colon mimicking physiological and microbiological conditions of the human large intestine. Supplementation with GABA-producing probiotic candidates did not affect the overall gut microbiota diversity over 48 h of treatment. However, we observed modulation of the microbiome composition, especially change of Bacteroides population, a key gut microbe associated with anti-depressive and anti-inflammatory activities. The level of microbiota-generated butyrate within 12 h of treatment was significantly increased compared to control. Results from this study demonstrated the probiotic potential of tested GABA-producing bacteria and their impact on gut microbiota structure and metabolism, suggesting their suitability for gut health-promoting application.