BCCMA: Targeting Gut-Microbiome in Veterans Deployment Related Gastrointestinal and Liver Diseases; CMA1- The Role of GWI Gut Microbiome in Susceptibility to Diarrheal Diseases

这一修订后的BLRD和CSRD合作优异奖（BCCMA）申请正在提交的一部分， 一组来自全国范围内胃肠道（GI）和肝脏疾病VA调查人员的5位连锁CMA， 在2019年5月参加了在圣地亚哥举行的成功的实地会议后， （由VAORD提供资金）。这次会议制定的路线图发表在《胃肠病学》杂志上 （PMC7249241）。这组CMA旨在深入了解肠道微生物组的新兴作用 在退伍军人部署相关的GI和肝脏疾病包括海湾战争疾病（GWI）的病理生理学中， 创伤后应激障碍（PTSD）和炎症性肠病（IBD），并开发潜力 生物治疗以减轻疾病症状。这一具体建议CMA 1是由以下事实驱动的： 虽然牙周病在患有GWI的退伍军人中非常普遍并且是高发病率的主要原因， GWI的病理生理学尚未明确，治疗选择不足。因此在 鉴于肠道微生物组在GWI中的新兴作用，迫切需要更好地了解 微生物生态失调的作用以及与肠道疾病和肠易激综合征发病率较高有关的机制 在这些退伍军人。最近的研究进一步强调了肠道微生物组在以下方面的关键作用： 易感染肠道病原体。例如，肠道微生物组已被证明是 感染和腹泻的易感性。啮齿类动物（CR，人类的鼠对应物 肠致病性e. coli）。此外，粪便微生物移植（FMT）为基础的治疗策略C。艰难 感染进一步支持肠道微生物组在消化道疾病中的关键作用。然而，直接因果关系 在GWI退伍军人中观察到的微生物生态失调与牙周病之间的关系尚未调查。在 在这方面，在初步研究中，我们建立了人源化GWI小鼠模型，其中来自GWI的FMT 退伍军人在小鼠14天几乎概括了一些功能性肠病的特点， 包括a）肠屏障完整性的显著失调;和B）轻度炎症， 通过中性粒细胞浸润评估。在人源化GWI小鼠中的另一个新的和惊人的发现是， 结肠关键氯转运蛋白表达减少（腺瘤下调）。值得注意的是， 降低的β-淀粉样蛋白表达是感染性或IBD相关性腹泻的关键事件， 屏障完整性受损。此外，在初步研究中，我们观察到， 易受CR感染。基于这些数据，我们假设"GWI退伍军人的生态失调是 与受损的屏障完整性和减少的ESTs表达相关， 增加退伍军人感染病原体和腹泻的易感性。我们建议利用国家- 现有技术的动物模型例如，人源化和常规GWI小鼠（暴露于海湾战争化学品），和 方法使用顶端外类肠/类结肠，诱导型过表达转基因小鼠，和体内 光学成像系统（IVIS），用于深入了解GWI中生态失调的作用。我们也 建议研究生物治疗剂的作用，例如，FMT来自健康的退伍军人，益生菌和细菌 代谢物丁酸在缓解肠道生态失调、对CR感染的易感性和肠道屏障完整性方面的作用。两 具体目标是：1）。确定人源化（FMT）和常规（FMT）的易感性 （化学诱导）GWI小鼠对C.啮齿类动物引起的腹泻，并阐明了潜在的 机制; 2）.制定旨在纠正生态失调和失调的有效策略 C.啮齿类感染的GWI小鼠模型。拟议研究的成功结果 可能会增加我们对GWI微生物组在易感性方面的作用的理解， IBS的发病率更高（因为反复发作的感染性腹泻会增加IBS的风险）， 开发新的生物治疗药物以缓解生态失调和相关的GWI症状。

This revised BLRD and CSRD Collaborative Merit Award (BCCMA) application is being submitted as part of a group of 5-linked CMAs from nationwide VA investigators in gastrointestinal (GI) and liver diseases, who formed a national steering committee after participating in a successful field-based meeting in San Diego in May 2019 (funded by VAORD). The roadmap developed at this meeting was published in the journal “Gastroenterology” (PMC7249241). This cluster of CMAs is aimed at in depth understanding of the emerging role of gut microbiome in the pathophysiology of Veterans deployment related GI and liver diseases including the Gulf War Illness (GWI), Post Traumatic Stress Disorder (PTSD) and Inflammatory Bowel Diseases (IBD), and to develop potential biotherapeutics to alleviate the disease symptoms. This specific proposal CMA1, is driven by the facts that while diarrheal disorders are highly prevalent in Veterans with GWI and are a major cause of high morbidity, the pathophysiology of GWI is not well-defined, and the treatment options are inadequate. Therefore, in view of the emerging role of the gut microbiome in GWI, there is a critical need to better understand the role of microbial dysbiosis and the mechanisms involved in higher incidence of diarrheal disorders and IBS in these Veterans. Recent studies have further highlighted the crucial role of gut microbiome in susceptibility to diarrheal pathogens. For example, gut microbiome has been shown to be the key determinant in susceptibility to infection and diarrhea by C. rodentium (CR, murine counterpart of the human enteropathogenic E. coli). Additionally, fecal microbial transplant (FMT) based treatment strategies for C. difficile infection further support the critical role of gut microbiome in diarrheal diseases. However, direct causal relationship of microbial dysbiosis observed in GWI Veterans and diarrheal illnesses remains uninvestigated. In this regard, in preliminary studies we established a humanized GWI mouse model where FMT from GWI Veterans in mice for 14 days almost recapitulated some features of the functional bowel disorders associated with GWI, including a) significant dysregulation in intestinal barrier integrity; and b) mild inflammation as assessed by neutrophil infiltration. Another novel and striking finding in the humanized GWI mice was a marked decrease in colonic expression of the key chloride transporter (DRA, Down Regulated in Adenoma). Of note, decreased DRA expression is a key event in infectious or IBD associated diarrhea and is also linked to compromised barrier integrity. Also, in preliminary studies, we observed that DRA KO mice were much more susceptible to CR infection. Based on these data, we hypothesize that “Dysbiosis in GWI Veterans is associated with compromised barrier integrity and decreased DRA expression which contributes to increased predisposition of veterans to pathogen infections and diarrhea. We propose to utilize state-of- the-art animal models e.g., the humanized and conventional GWI mice (exposure to gulf war chemicals), and approaches using apical-out enteroids/colonoids, inducible DRA overexpressing transgenic mice, and in vivo optical imaging system (IVIS) for in depth mechanistic understanding of the role of dysbiosis in GWI. We also propose to investigate the role of biotherapeutics e.g., FMT from healthy Veterans, probiotics, and a bacterial metabolite butyrate in alleviating gut dysbiosis, susceptibility to CR infection and gut barrier integrity. Two Specific Aims are proposed: 1). Determine the susceptibility of humanized (FMT) and conventional (chemical induced) GWI mice to C. rodentium induced diarrhea and elucidate the underlying mechanisms; 2). Develop effective strategies aimed at correcting dysbiosis and diarrheal phenotype in C. rodentium infected GWI mouse models. A successful outcome of the proposed studies is likely to increase our understanding of the role of GWI microbiome in susceptibility to diarrheal diseases, higher incidence of IBS (as repeated bouts of infectious diarrhea increase the risk of IBS) and has potential of developing novel biotherapeutics for alleviation of dysbiosis and associated GWI symptoms.