Doctoral Dissertation Improvement: Social change, parasite exposure and immune dysregulation: An evolutionary medicine approach

最近的两个假说--卫生假说和消失的微生物群假说--认为工业化国家过敏和自身免疫性疾病的急剧增加源于病原体暴露的减少。这些假设表明，当代生活方式与人类进化的生物学之间存在不匹配。与生活在欠发达国家的人相比，生活在美国等发达国家的人接触寄生蠕虫和细菌的机会减少，肠道微生物组成也发生了总体变化。这些变化似乎导致免疫刺激减少，对过敏和自身免疫性疾病的易感性增加，这在非西方人群中几乎不存在。本论文研究的博士生塔拉Cepon（俄勒冈州大学），在博士的监督下。詹姆斯·斯沃斯格拉斯，测试卫生和消失的微生物群假说之间的Shuar，一个forager-hortgarturalist人口从亚马逊厄瓜多尔谁目前正在经历快速而不平衡的文化变化与融入市场经济。该项目研究了社会/生活方式因素之间的关系，肠道寄生虫的组成，以及三个地理上分离的Shuar社区经历不同程度的市场参与和相关的社会变化之间的免疫功能和失调。通过家庭访谈，粪便样本的显微镜和分子分析，以及免疫功能的生物标志物，本项目将揭示寄生虫暴露模式和人类作为寄生虫居民生态系统的作用，以及这些居民对免疫发育和功能的贡献。这项研究还将通过关注环境变化如何影响传染病和自身免疫性疾病的患病率来提高对文化变化对健康影响的认识。除了这些贡献之外，这项研究对公共卫生政策，社区外展，国际科学伙伴关系和教育具有重要意义。这项研究增加了我们对市场相关变化对Shuar人健康变化的影响的理解，并延伸到其他正在经历文化变革的人群。此外，它有可能提供可用于改善当地和全球健康的见解，确定生活方式因素，以实施减少传染病和慢性病负担的政策。最后，该项目将培养一名女科学家，并为本科生提供研究机会。

Two recent hypotheses--the Hygiene Hypothesis and the Disappearing Microbiota Hypothesis--argue that the dramatic rise in allergies and autoimmune disorders in industrialized nations stems from decreased exposure to pathogens. These hypotheses posit a mismatch between contemporary lifestyles and the evolved biology of the human species. People living in developed nations such as the United States are experiencing reduced exposure to parasitic worms and bacteria, as well as overall changes to the microbial composition of the gut, compared to individuals living in less developed nations. These changes appear to be resulting in decreased immune stimulation and an increased vulnerability to allergy and autoimmune diseases, which are nearly absent in non-Western populations. The present dissertation study by doctoral student Tara Cepon (University of Oregon), under the supervision of Dr. James Snodgrass, tests both the Hygiene and Disappearing Microbiota Hypotheses among the Shuar, a forager-horticulturalist population from Amazonian Ecuador who are currently experiencing rapid yet uneven cultural change related to integration into the market-based economy. The project examines relationships among social/lifestyle factors, intestinal parasite composition, and immune function and dysregulation among three geographically separated Shuar communities experiencing different degrees of market involvement and related social change. Through household interviews, microscopic and molecular analyses of fecal samples, and biomarkers of immune function, the present project will shed light on patterns of parasite exposure and the role of humans as ecosystems for our parasitic residents, as well as the contribution that these residents make to immune development and function. This study also will advance knowledge of the health effects of cultural change by focusing needed attention on how environmental shifts affect infectious and autoimmune disease prevalence. Beyond these contributions, this study has important implications for public health policy, community outreach, international science partnerships, and education. The research increases our understanding of the effects of market-related changes on health variation among Shuar and, by extension, other populations undergoing cultural change. Further, it has the potential to provide insights that can be used for improving local and global health by identifying lifestyle factors to target when implementing policies to reduce infectious and chronic disease burden. Finally, this project will train a female scientist and will provide research opportunities for undergraduates.