Evaluation of analytical tools for studying the host and gut microbe relationships in Type 2 Diabetes

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Amanda L. Watson (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Norman Chiu

Abstract: Type 2 Diabetes (T2D) is becoming one of the most prevalent diseases in the world. With this comes an increased burden in healthcare and a lower quality of life for those affected by diabetes. Further, certain populations are more susceptible to T2D than others. For example, in the US, the Hispanic population has the second highest rate of T2D while those of Caucasian heritage have the lowest rate of T2D. Studies have shown that different environment and socioeconomic standing is not enough to explain the increased prevalence of diabetes in the Hispanic population. There must be other factors involved in disease susceptibility. Specifically, there is evidence that genetic variation and the gut microbiome play a role in human health and disease development including in T2D. Furthermore, the Hispanic population is the least studied of all populations for diabetes. Therefore, we set out to examine these factors that may increase the susceptibility for T2D in Hispanic population. To facilitate the studies on these factors, a number of new analytical tools were evaluated. First, by using a new beadarray chip that was developed by a consortium of experts in T2D and other related diseases, a pilot study on the genetic variations of Hispanic population with T2D was completed. To determine the adequate size of cohort for this study, a reference database of a larger diabetes genetic study was used. Using the method of principle components analysis (PCA), it has shown that the genetic information obtained from more than 20 participants would have sufficient resolving power to determine whether a particular participant was healthy or diseased, providing sufficient SNP genotypes are included in the PCA analysis. Following this, a genetic study was completed on an adult Hispanic population and 26 new SNPs were found to be associated with T2D through comparison with reference populations and PCA analysis. Future work will involve increasing the size of cohort to validate the identified SNPs and to further evaluate the use of SNP genotypes to define the host for studying the host - gut microbe relationships. Second, recent studies have indicated the gut microbiome that lives in symbiosis with the human host can influence our health. More recently, there are evidences that gut microbes can also increase the susceptibility for T2D. Extensive work has been done to identify the microbes in the gut, but studying the activity of gut microbes is still under development. Therefore, we set out to build a simple model of gut microbes aiming to explore new ways to measure the activity. Lactobacillus helveticus, a probiotic gram-positive bacteria was used to build the model. The enzymatic activity of beta-galactosidase (ß-gal) was assayed with a fluorescent substrate called 4-methylumbelliferyl ß-D-galactopyranoside. To ensure the ß-gal assay is compatible with subsequent studies, a whole-cell format was adopted. Since no protocol for the selected gram-positive microbe was available, the assay was developed by reducing the background noise and brought the assay time to one day with a linear dynamic range over two orders of magnitude. To validate the results, the ß-gal assay was repeated on a different bacterial strain. With the developed ß-gal assay, building the gut microbe model can continue towards evaluating microbe activity in relationship with the host in health and disease.

Additional Information

Language: English
Date: 2016
Genetics, Gut Microbe, Method Development, Type 2 Diabetes
Non-insulin-dependent diabetes $x Genetic aspects
Hispanic Americans $x Health and hygiene
Intestines $x Microbiology

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