Doctoral Dissertation Research: Investigating human diet and the oral microbiome in ancient and living Pacific Northwest Coast indigenous communities

人类生物和文化进化的几个重要时期都与饮食的变化有关。口腔微生物群，即生活在人类口腔中的细菌群落，也会受到个人饮食的影响，这可能是饮食转变如何影响人类进化的另一个迹象。该项目通过与北美西北海岸居住了6000多年的土著社区合作，研究人类饮食与口腔微生物群之间的联系。这项合作将使研究人员能够重建一个适应以海洋为主的饮食的古代群落的口腔微生物群，并评估与饮食变化相关的重大社会和文化转变，如欧洲殖民，可能会影响口腔微生物群。这项研究将使我们了解人类进化史与现代人类经历之间的关系，例如在北美许多土著社区记录的健康差异。该项目还将包括以社区为基础的项目，如开发祖先“屋”，以恭敬地储存等待实验室分析的土著人类遗骸。该项目借鉴了西方科学研究方法和土著社区知识和口述历史。研究人员将首先利用尖端的古代DNA测序方法、稳定同位素分析和口述历史相结合，重建祖先土著社区的饮食和口腔微生物群。在与欧洲人接触之前，这个古老的社区经历了一个社会复杂性日益增加的时期，过渡到大型的、分层的、基于世系的、多代同堂的家庭，这些家庭很可能控制着当地的食物资源。在这样一个不平等的社区里，经常会有个人地位的差异。本研究将评估地位分化和社会复杂性的增加如何影响个人饮食和食物资源的获取，以及口腔中的细菌如何对这些变化做出反应。然后将这一古老群落的饮食和口腔微生物组与现存后代群落的类似数据进行比较，以评估由于欧洲殖民和西方工业化加工食品的引入，他们目前的饮食与祖先的饮食有何不同，并了解这种变化是否影响了口腔微生物组的细菌组成。这项研究将为理解欧洲殖民的生物学后果提供一种新的方法。

Several significant periods in human biological and cultural evolution have been correlated with changes in diet. The oral microbiome, communities of bacteria living in the human mouth, can also be influenced by individual diet and may be another indication of how human evolution has been shaped by dietary transitions. This project examines the link between human diet and the oral microbiome by collaborating with an indigenous community who have lived along the Northwest Coast of North America for over 6,000 years. This collaboration will allow the researchers to reconstruct the oral microbiome of an ancient community adapted to a predominantly marine diet, and assess how significant social and cultural transitions associated with dietary changes, such as European colonization, may have influenced the oral microbiome. The research will inform our understanding of the relationship between human evolutionary history and modern human experiences, such as the health disparities documented in many indigenous communities of North America. This project will also incorporate community-based projects like the development of an Ancestor "House" room to respectfully store indigenous human remains awaiting laboratory analysis.This project draws on both Western science research methods and indigenous community knowledge and oral history. The researchers will first reconstruct the diet and oral microbiome of the ancestral indigenous community using a combination of cutting edge ancient DNA sequencing methods, stable isotope analysis, and oral history. Prior to European contact, this ancient community underwent a period of increasing social complexity, transitioning to villages with large, stratified, lineage-based, multigenerational households, which likely controlled local food resources. In non-egalitarian communities like this, there are often individual status differences. This research will assess how increased status differentiation and social complexity influenced individual diet and access to food resources, and how the bacteria in the oral cavity responded to these changes. The diet and oral microbiome of this ancient community will then be compared to similar data from the living descendant community to assess how their current diet may be different from that of their ancestors, as a result of European colonization and the introduction of Western industrialized processed foods, and to understand if this change has influenced the bacterial composition of the oral microbiome. This research will provide a novel approach to understanding the biological consequences of European colonization.