All ETDs from UAB

Advisory Committee Chair

Tim R Nagy

Advisory Committee Members

Daniel L Smith

David B Allison

Casey D Morrow

Robin G Lorenz

Document Type


Date of Award


Degree Name by School

Doctor of Philosophy (PhD) School of Health Professions


The gut microbiome has been found to be associated with obesity, type 2 diabetes and many other diseases. Many studies have shown microbial composition changes with obese status or switching of diets. However, few of them have investigated the long-term microbial changes in subjects under the same environmental factors. This study examined gut microbiome changes in multiple aspects with well-controlled diet-induced obese mice models and demonstrated the following: there were great variations in gut microbiome composition and diversity in the same strain of inbred mice under the same environment and diet; certain lineages of bacteria were associated with digestive efficiency; gut microbiome changes were dose dependent on different levels of calorie restriction; gut microbiome were relatively stable in adult aging under fixed feeding regimen; weight cycling through manipulating the amounts of diet intake could have differential effects on microbiome composition and specific categories of bacteria; and microbial compositions at a younger age were different between short-lived and long-lived mice. In summary, this study provides substantial insight into the roles of gut microbiome in obesity, calorie restriction and aging with well-controlled experimental subjects and conditions. These results also provide a rationale for future interventional study and subsequent clinical application in the prevention and treatment of obesity, as well as potential strategies for promoting longevity.