Matching Items (2)
Description
College weight gain and obesity are significant problems impacting our society, leading to a considerable number of comorbidities during and after college. Gut microbiota are increasingly recognized for their role in obesity and weight gain. Currently, research exploring the gut microbiome and its associations with dietary intake and body mass index (BMI) is limited among this population. Therefore, the purpose of this study was to assess associations between the gut microbiome, BMI, and dietary intake in a population of healthy college students living in two dorms at Arizona State University (n=90). Cross-sectional analyses were undertaken including 24-hour dietary recalls and anthropometrics (height, weight and BMI). High throughput Bacterial 16S rRNA gene sequencing of fecal samples was performed to quantify the gut microbiome and analyses were performed at phyla and family levels. Within this population, the mean BMI was 24.4 ± 5.3 kg/m2 and mean caloric intake was 1684 ± 947 kcals/day. Bacterial community analysis revealed that there were four predominant phyla and 12 predominant families accounting for 99.3% and 97.1% of overall microbial communities, respectively. Results of this study suggested that a significant association occurred between one principal component (impacted most by 22 microbial genera primarily within Firmicutes) and BMI (R2=0.053, p=0.0301). No significant correlations or group differences were observed when assessing the Firmicutes/Bacteroidetes ratio in relation to BMI or habitual dietary intake. These results provide a basis for gut microbiome research in college populations. Although, findings suggest that groups of microbial genera may be most influential in obesity, further longitudinal research is necessary to more accurately describe these associations over me. Findings from future research may be used to develop interventions to shift the gut microbiome to help moderate or prevent excess weight gain during this important life stage.
ContributorsHotz, Ricci-Lee (Author) / Whisner, Corrie (Thesis advisor) / Bruening, Meredith (Committee member) / Vega-Lopez, Sonia (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2016
Description
First year college students have been identified as a vulnerable population for weight gain and the onset of overweight and obesity. Research regarding the gut microbiome has identified differences in the microbial composition of overweight and obese individuals compared to normal weight individuals. Dietary components like dietary fibers, act as prebiotics, or fermentable substrate, that the gut microbiota use for metabolic functions including the production of short-chain fatty acids. The objective of this longitudinal, observational study was to assess changes in the gut microbiota over time in relation to changes in fiber consumption in healthy college students at a large a southwestern university (n=137). Anthropometric and fecal samples were collected at the beginning and end of the fall and spring semesters between August 2015 and May 2016. Both alpha, within sample, diversity and beta, between sample, diversity of participant gut microbes were assessed longitudinally using non-parametric pairwise (pre-post) comparisons and linear mixed effect (LME) models which also adjusted for covariates and accounted for time as a random effect. Alpha and beta diversity were also explored using LME first difference metrics and LME first distance metrics, respectively, to understand rates of change over time in microbial richness/phylogeny and community structure. Pre-post comparisons of Shannon Diversity and Faith’s PD were not significantly different within participant groups of fiber change (Shannon diversity, p=0.96 and Faith’s PD, p=0.66). Beta diversity pairwise comparisons also did not differ by fiber consumption groups (Unweighted UniFrac p=0.182 and Bray Curtis p=0.657). Similarly, none of the LME models suggested significant associations between dietary fiber consumption and metrics of alpha and beta diversity. Overall, data from this study indicates that small changes in fiber consumption among a free-living population did not have an impact on gut microbial richness, phylogeny or community structure. This may have been due to the low intake (~15 g/d) of fiber. Further study is needed to fully elucidate the role that fiber plays in the diversity and composition of the gut microbiota, especially when delivered from a variety of food sources rather than fiber supplements.
ContributorsLolley, Sarah (Author) / Whisner, Corrie (Thesis advisor) / Sears, Dorothy (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2020