Matching Items (2)
153139-Thumbnail Image.png
Description
While obesity rates have plateaued within the last decade,

two-thirds of the United States

population is currently classified as overweight (defined a

s a body mass index [BMI] of

25-29.9 kg/m²) or obese (a BMI greater than 30 kg/m²). Bariatric

surgical interventions

are not only more effective than behavioral treatments

in

While obesity rates have plateaued within the last decade,

two-thirds of the United States

population is currently classified as overweight (defined a

s a body mass index [BMI] of

25-29.9 kg/m²) or obese (a BMI greater than 30 kg/m²). Bariatric

surgical interventions

are not only more effective than behavioral treatments

in the short term but are the only

form of obesity intervention with evidence of consisten

t long-term effectiveness.

However, even among bariatric surgery patients, weight

loss often stabilizes and it is

estimated that more than 20% of bariatric surgery patient

s will regain a significant

amount of weight that was initially lost long-term. Li

ttle research to date has been

conducted on physical activity in post bariatric surgery pati

ents. More specifically, there

have been no studies to date examining the effects of Me

ditative Movement (MM)

programs on body composition in bariatric patients. A s

tudy using an 8-week Tai Chi

Easy program was conducted in female gastric bypass patient

s to explore feasibility of

MM in the bariatric population as well as pre- and post-in

tervention changes in weight,

mindfulness, eating behaviors, body awareness, physical a

ctivity patterns, dietary quality

and mood. Data analysis revealed that there were no s

ignificant changes in weight or

physical activity patterns; however, significant changes w

ere observed in anxiety, overall

body awareness and cognitive restraint in eating. Addit

ionally, a significant decrease in

processed meat consumption and a weak trend towards increa

sed consumption of fruits

may suggest an overall improvement in dietary quality.
ContributorsSmith, Lisa L. (Author) / Larkey, Linda K (Thesis advisor) / Ainsworth, Barbara (Committee member) / Chisum, Jack (Committee member) / Ohri-Vachaspati, Punam (Committee member) / McClain, Darya (Committee member) / Arizona State University (Publisher)
Created2014
154958-Thumbnail Image.png
Description
Obesity is a worldwide epidemic accompanied by multiple comorbidities. Bariatric surgery is currently the most efficient treatment for morbid obesity and its comorbidities. The etiology of obesity is unknown, although genetic, environmental, and most recently, microbiome elements have been recognized as contributors to this rising epidemic. The

Obesity is a worldwide epidemic accompanied by multiple comorbidities. Bariatric surgery is currently the most efficient treatment for morbid obesity and its comorbidities. The etiology of obesity is unknown, although genetic, environmental, and most recently, microbiome elements have been recognized as contributors to this rising epidemic. The role of the gut microbiome in weight-loss or weight-gain warrants investigation, and bariatric surgery provides a good model to study influences of the microbiome on host metabolism. The underlying goals of my research were to analyze (i) the factors that change the microbiome after bariatric surgery, (ii) the effects of different types of bariatric surgeries on the gut microbiome and metabolism, (iii) the role of the microbiome on the success of bariatric surgery, and (iv) temporal and spatial changes of the microbiome after bariatric surgery.

Roux-en-Y gastric bypass (RYGB) rearranges the gastrointestinal tract and reduces gastric acid secretions. Therefore, pH could be one of the factors that change microbiome after RYGB. Using mixed-cultures and co-cultures of species enriched after RYGB, I showed that as small as 0.5 units higher gut pH can aid in the survival of acid-sensitive microorganisms after RYGB and alter gut microbiome function towards the production of weight loss-associated metabolites. By comparing microbiome after two different bariatric surgeries, RYGB and laparoscopic adjustable gastric banding (LAGB), I revealed that gut microbiome structure and metabolism after RYGB are remarkably different than LAGB, and LAGB change microbiome minimally. Given the distinct RYGB alterations to the microbiome, I examined the contribution of the microbiome to weight loss. Analyses revealed that Fusobacterium might lessen the success of RYGB by producing putrescine, which may enhance weight-gain and could serve as biomarker for unsuccessful RYGB.

Finally, I showed that RYGB alters the luminal and the mucosal microbiome. Changes in gut microbial metabolic products occur in the short-term and persist over the long-term. Overall, the work in this dissertation provides insight into how the gut microbiome structure and function is altered after bariatric surgery, and how these changes potentially affect the host metabolism. These findings will be helpful in subsequent development of microbiome-based therapeutics to treat obesity.
ContributorsIlhan, Zehra Esra (Author) / Krajmalnik-Brown, Rosa (Thesis advisor) / DiBaise, John K. (Committee member) / Cadillo-Quiroz, Hinsby (Committee member) / Rittmann, Bruce E. (Committee member) / Arizona State University (Publisher)
Created2016