Adaptation to diet and its impact on the gut microbiome and genomic variation

点击翻译按钮获取中文摘要

Diets vary greatly across the globe, and our ability to digest foods depends on genes present in the human genome and bacteria found in the human gut (i.e., the gut microbiome). Within the past few years, scientists have discovered that the gut microbiome has a very important influence on human physiology and can impact nutritional status, as well as disease risk. Indeed, variation in the gut micriobiome is thought to play a role in obesity, malnutrition, auto-immune disease, and infectious disease susceptibility. However, we do not know how much gut bacteria vary across diverse human populations, and what may account for that variation. In addition, substantial variation exists for human genes involved in digestion, nutrition, and immunity, particularly for African populations. By focusing on ethnically and geographically diverse Africans practicing a variety of human diets, this research project can significantly contribute to understanding these fundamentally important aspects of the biology of our species, addressing fundamental questions about modern human history and the genetic basis of traits related to human biology and adaptation.The research will include field studies of three hunter-gather, three pastoralist, and three agriculturalist populations in Eastern, Central, and Southern Africa. Data collected will include anthropometric measurements (e.g. height, weight, and body mass), DNA sequences of diverse Africans, lactose tolerance data, detailed information about diet and nutrition, and fecal samples (which will allow assessment of bacteria present in the gut microbiome). The gut microbiome data will be integrated with detailed information about nutrition, as well as anthropometric, metabolic, and genetic data, to better understand the genetic and environmental factors that contribute to human adaptation to diet. For example, gut bacteria in pastoralists who drink large quantities of milk may be enriched for species that can metabolize the sugar lactose present in milk and, thus, may be informative for studying factors contributing to lactose tolerance, as well as for understanding gene, culture, and bacterial co-adaptation at a larger scale. The project will make a number of significant contributions to the fields of anthropology, genetics, microbiology, and evolutionary biology. Given the existing gap in our knowledge of African genetic and phenotypic diversity relative to other geographic regions, the publically-available data generated by the research will be an important resource for anthropologists, microbiologists, and genetic researchers, contributing to studies of human origins and the design and interpretation of disease association studies. Additionally, because the gut microbiome has a large influence on nutrition, metabolism and immune response, this research project could have an important impact on understanding risk factors for diabetes, infectious disease and under-nutrition. And through the collaborative research, this project also will contribute significantly to the research training of both American and African students and scientists.