The gut microbiota, defined as all the microbes that live in the intestinal tract, has recently been shown by labs around the world to interact powerfully with the human body to impact overall metabolic rate, fat accumulation, heart disease, and insulin sensitivity. The microbiota produces metabolites that enter the blood stream and circulate throughout the body, including some that are know to promote atherosclerosis and some that can cross the blood-brain barrier. There is even evidence that the microbiota is involved in neurological development and mental health disorders such as anxiety and depression. To learn more about this emerging field, Dr. Bridgewater recently spent two semesters on sabbatical at Shanghai Jiao Tong University in China, working in the lab of Dr. Liping Zhao, a world expert on gut microbiota. The study they performed addressed the effects of high fat diet and stress on the gut microbiota (by metagenomic analysis) and on anxiety-like behaviors. Interesting differences emerged in the ways that males and females respond to an unhealthy diet and to stress , suggesting that gut microbiota-targeted therapies developed for humans will likely affect males and females differently.
Back at BYU, the Bridgewater Lab is involved in an ongoing study of a mutant mouse line that lacks the PAS kinase gene. PAS kinase plays a central role in regulating glucose metabolism, and mutations in its gene can cause a rare form of diabetes. The PAS kinase knockout mouse is resistant to high fat diet-induced obesity, diabetes, and fatty liver. We are using this model system to examine the converging effects of diet and genetics on the composition of the gut microbiota.
1. Bridgewater LC, Zhang C, Wu Y, Hu W, Zhang Q, Wang J, Li S, Zhao L: Gender-based differences in host behavior and gut microbiota composition in response to high fat diet and stress in a mouse model. In preparation, 2015.
Other microbiota-related publications
1. Long, W., Xue, Z., Zhang, Q., Feng, Z., Bridgewater, L.C., Wang, L., Zhao, L., Pang, X. “Differential responses of gut microbiota to the same prebiotic formula in oligotrophic and eutrophic batch fermentation systems.” Scientific Reports (2015). In press.
2. Zhang, C., Yin, A., Li, H., Wang, R., Wu, G., Shen, J., Zhang, M., Wang, L., Hou, Y., Ouyang, H., Zhang, Y., Zheng, Y., Wang, J., Lv, X., Wang, Y., Zhang, F., Zeng, B., Li, W., Yan, F., Zhao, Y., Pang, X., Zhang, X., Fu, H., Chen, F., Zhao, N., Hamaker, B.R., Bridgewater, L.C., Weinkove, D., Clement, K., Dore, J., Holmes, E., Xiao, H., Zhao, G., Yang, S., Bork, P., Nicholson, J.K., Wei, H., Tang, H., Zhang, X., Zhao, L. “Dietary modulation of gut microbiota contributes to alleviation of both genetic and simple obesity in children.” EBioMedicine . http://dx.doi.org/10.1016/j.ebiom.2015.07.007 (2015).
3. Xue, Z., Zhang, W., Wang, L., Hou, R., Zhang, M., Fei, L., Zhang, X., Huang, H., Bridgewater, L., Jiang, Y., Jiang, C., Zhao, L., Pang, X., and Zhang, Z. “The bamboo-eating giant panda harbors a carnivore-like gut microbiota, with excessive seasonal variations.” mBio 6:3, doi: 10.1128/mBio.00022-15 (2015).
4. Chen, H., Liu, Y., Zhang, M., Wang, G., Qi, Z., Bridgewater, L.C., Zhao, L., Tang, Z, Pang, X. “A Filifactor alocis-centered co-occurrence group associates with periodontitis across different oral habitats.” Scientific Reports 5:9053, doi: 10.1038/srep09053 (2015).