Collaborative Research: The interplay between host diet, immunity, reproduction, and the microbiome across an anthropogenic-disturbed landscape

最近已经很明显，动物消化道内的微生物不仅对消化很重要，而且还影响整体健康。动物体内有数以万亿计的微生物，但拥有这些微生物的影响是未知的。到目前为止，我们所知道的主要是微生物对消化的重要性。然而，目前的研究表明，动物体内的微生物的影响远远超出了肠道，它们会影响免疫系统，甚至会影响压力。该项目旨在了解这些微生物对自由生活的濒危鬣蜥种群的健康和生存的重要性，这些种群通过生态旅游暴露于不断变化和不自然的饮食中。该项目将测试变化的微生物群落和关键生理参数如何与自然种群的繁殖和生存相关。此外，在实验室中，研究人员将通过实验测试饮食、压力和微生物的变化如何影响健康和生理，以了解导致野生鬣蜥观察到的变化的原因。将生理和微生物变化与自然界动物种群波动联系起来将是一个创新的进步。最后，了解这些相互作用的发生和方向将为人类引起的饮食变化对野生动物的影响提供重要的见解，并为濒危物种提供急需的生物学知识。最近的许多研究已经确定了模型系统中微生物组和宿主健康之间的重要联系。然而，微生物组和生理功能之间的机制联系是健康和生存的关键，但大部分仍未被探索。此外，鉴于进化史是微生物组组成的主要决定因素之一，分类宽度的缺乏严重限制了对宿主栖息地、饮食和免疫与微生物组组成和宏基因组功能之间生理联系的理解。在自由生活的动物中调查微生物群落和健康相关指标的研究也很缺乏。因此，目前对这些关系的认识缺乏关键的生态学相关性和对环境变化对内微生物群落影响的理解。为了解决这些目前的知识空白，该项目将研究自然环境和圈养环境下的鬣蜥，以测试生态免疫指数、人为饮食变化和巴哈马群岛碎片化岛屿景观中微生物群之间的关系。在实验室中，主要研究人员将对圈养鬣蜥进行生态学相关的实验操作，以测试野生种群的定向关系。主要研究人员还将结合长期标记重获数据集（37年以上）调查这些关联随时间的稳定性，以估计生态免疫学、氧化和微生物组指数对暴露于可变人类影响的不同种群的生殖输出和生存的影响。该奖项由生物科学理事会内的综合有机体系统部、环境生物学部和生命规则风险基金共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

It has recently become evident that microbes within the digestive tract of an animal are not only important for digestion but also influence overall health. An animal lives with trillions of microorganisms in its body, yet the implications of having most of these microorganisms are unknown. What is known thus far is focused primarily on the importance of microorganisms for digestion. However, current work suggests that an animal's microbes have effects that extend far beyond the gut, impacting the immune system and even stress. This project seeks to understand the importance of these microorganisms for health and survival in free-living populations of endangered iguanas that are exposed to changing and unnatural diets via ecotourism. The project will test how changing microbial communities and key physiological parameters relate to reproduction and survival in natural populations. Additionally, in the laboratory the researchers will experimentally test how changes in diet, stress, and microbes affect health and physiology in order to understand what is causing the observed changes in wild iguanas. Connecting physiological and microbial changes with animal population fluctuations in nature will be an innovative step forward. Finally, understanding both the occurrence and direction of these interactions will provide important insights into the effects of human-induced diet shifts on wildlife and much needed biological knowledge regarding threatened species.Many recent studies have identified significant connections between the microbiome and host health in model systems. However, mechanistic links between the microbiome and physiological functions that are key to health and survival remain mostly unexplored. Furthermore, given that evolutionary history is one of the primary determinants of microbiome composition, the lack of taxonomic breadth severely restricts understanding of the physiological link between host habitat, diet, and immunity with microbiome composition and metagenomic function. There is also a paucity of research investigating microbial communities and health-related metrics within free-living animals. Thus, current knowledge of these relationships lacks critical ecological relevance and an understanding of the impact of environmental changes on endo-microbial communities. To address these current knowledge gaps, the project will study iguanas in both natural and captive settings, in order to test relationships among ecoimmune indices, anthropogenic-based diet changes, and the microbiome across a fragmented, insular landscape in The Bahamas. In the laboratory, the principal investigators will perform ecologically-relevant experimental manipulations in captive iguanas to test directional relationships in wild populations. The principal investigators will also investigate the stability of these associations over time in conjunction with a long-term mark recapture data set (37+ years) to estimate the influence of ecoimmunological, oxidative, and microbiome indices on reproductive output and survival across different populations exposed to variable human influence.This award was co-funded by the Division of Integrative Organismal Systems, the Division of Environmental Biology, and the Rules of Life Venture Fund within The Directorate for Biological Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.