Date of Defense
6-11-2024 11:00 AM
Location
F3-021
Document Type
Thesis Defense
Degree Name
Master of Science in Chemistry
College
College of Science
Department
Chemistry
First Advisor
Dr. Nayla Munawar
Keywords
Probiotics, prebiotics, non-digestible fibers, oligosaccharides, short chain fatty acids (SCFAs), metabolites, antioxidants, antimicrobial.
Abstract
Probiotics and prebiotics play a major role in enhancing the gut microbiota and, consequently, human health. Non-digestible dietary fibers (prebiotics) are selectively fermented and induce specific changes in the composition and/or activity of the gastrointestinal microbiota (probiotics), thus conferring benefit(s) upon the host's health. The consumption of prebiotic products has been extended from diet supplementation to clinical application in various health complications, emerging as a potential therapeutic to manipulate several diseases. Different pharmaceutical companies normally use a blend of many fibers from various sources to prepare commercial prebiotic products. Currently, no data is available to what extent the components of prebiotic supplements are non-digestible by humans and fermentable by healthy gut microbial populations for their growth to maintain host health. Hence, the main objective of this thesis was to evaluate the effect of commercial and novel fibers on the growth of probiotics (beneficial gut microorganisms) isolated in the lab from commercial probiotics-containing products (yogurt Y strain, and probiotic sachet S strain) and bacterial consortium of 6 most abundant gut strains in aerobic and anaerobic conditions. The metabolism/fermentation of prebiotics has been evaluated using the TLC method, and the metabolite produced by different probiotics using different fiber blends under different growth conditions has also been assessed. Furthermore, the antimicrobial and antioxidant activities of metabolites were evaluated to map the biological role of gut metabolites in the host. Different microbial strains selectively utilized fiber supplements and produced a very interesting metabolic profile with significant differences in types and amounts of metabolites under aerobic and anaerobic growth conditions. Metabolites produced under anaerobic conditions showed a drop in pH and high biological activities as compared to the metabolites produced under aerobic conditions by the same microorganisms. Our results show that levan should also be added in commercial blends as it not only enhances gut microbial growth but also results in the production of bioactive metabolites after fermentation. The primary issue was the lack of an anaerobic facility, which limited our work to the analysis of 3 commercial blends under anaerobic conditions. So, for future studies, all prebiotic samples will be tested anaerobically, and metabolites will be identified using GC-MS, LC-MS, and HPLC. Their biological activities, like antioxidant and immunomodulation in vitro using cell lines and in vivo using mouse models, will also be evaluated.
Included in
PHYSIOCHEMICAL CHARACTERIZATION AND IN-VITRO INVESTIGATION OF THE EFFECT OF COMMERCIAL AND NOVEL NON-DIGESTIBLE FIBER/PREBIOTICS ON THE GROWTH OF PROBIOTICS
F3-021
Probiotics and prebiotics play a major role in enhancing the gut microbiota and, consequently, human health. Non-digestible dietary fibers (prebiotics) are selectively fermented and induce specific changes in the composition and/or activity of the gastrointestinal microbiota (probiotics), thus conferring benefit(s) upon the host's health. The consumption of prebiotic products has been extended from diet supplementation to clinical application in various health complications, emerging as a potential therapeutic to manipulate several diseases. Different pharmaceutical companies normally use a blend of many fibers from various sources to prepare commercial prebiotic products. Currently, no data is available to what extent the components of prebiotic supplements are non-digestible by humans and fermentable by healthy gut microbial populations for their growth to maintain host health. Hence, the main objective of this thesis was to evaluate the effect of commercial and novel fibers on the growth of probiotics (beneficial gut microorganisms) isolated in the lab from commercial probiotics-containing products (yogurt Y strain, and probiotic sachet S strain) and bacterial consortium of 6 most abundant gut strains in aerobic and anaerobic conditions. The metabolism/fermentation of prebiotics has been evaluated using the TLC method, and the metabolite produced by different probiotics using different fiber blends under different growth conditions has also been assessed. Furthermore, the antimicrobial and antioxidant activities of metabolites were evaluated to map the biological role of gut metabolites in the host. Different microbial strains selectively utilized fiber supplements and produced a very interesting metabolic profile with significant differences in types and amounts of metabolites under aerobic and anaerobic growth conditions. Metabolites produced under anaerobic conditions showed a drop in pH and high biological activities as compared to the metabolites produced under aerobic conditions by the same microorganisms. Our results show that levan should also be added in commercial blends as it not only enhances gut microbial growth but also results in the production of bioactive metabolites after fermentation. The primary issue was the lack of an anaerobic facility, which limited our work to the analysis of 3 commercial blends under anaerobic conditions. So, for future studies, all prebiotic samples will be tested anaerobically, and metabolites will be identified using GC-MS, LC-MS, and HPLC. Their biological activities, like antioxidant and immunomodulation in vitro using cell lines and in vivo using mouse models, will also be evaluated.