Proanthocyanidin metabolites produced by commensal gut microbes may promote metabolic resilience

项目总结：这项多学科的提案旨在定义原花青素(PAC)这一主要类别 葡萄多酚(GP)，改变肠道环境以促进与弹性相关的生物学特征 代谢综合征(METS)和2型糖尿病(T2D)。使用尿液、血液和肠道微生物区系样本 添加PAC的小鼠和添加GP的人类，微生物组范围的关联研究将是 用于将细菌菌株/物种的变化与微生物代谢物的增加/减少相关联 (彩信)。PAC对体外细菌和接种细菌分离物或确定的无菌小鼠的治疗 财团将在特定的共生菌和PAC衍生的MMS之间建立关系，这将 然后在哺乳动物细胞培养试验和高脂饮食(HFD)诱导的单核细胞培养中进行生物活性测试。 Mets/T2D联合无菌(GF)模型。PAC与新陈代谢韧性有关；然而， 由于普遍较差的吸收和不确定性，系统性保护机制(S)仍然难以捉摸 关于分子靶标。PAC到达结肠，在那里它们被生物转化为MM，生物利用度更高； 然而，负责这些转化的特定细菌，所产生的MM的分子靶点，以及 它们在METS/T2D临床前模型中的有效性仍有待调查。我们观察到全科医生 补充剂可以诱导粘液溶解肠道细菌Akkermansia visiniPhila的水华，与 降低血清脂多糖，减轻肠道和全身炎症，增加紧张素基因表达 连接蛋白封闭，改善葡萄糖代谢，减少肥胖和体重增加的高脂饮食小鼠。 在胃旁路手术和二甲双胍治疗后，观察到粘液嗜酸杆菌的数量增加。 强调其在积极代谢结果中的重要性。补充GP的小鼠也表现出：1)降低 细菌群落丰富度；2)与改善肠道屏障完整性和乳酸一致的属的变化 产酸；3)降低血清细菌衍生的二次胆汁酸水平；4)减少 与肠上皮相邻的粘液层，粘液在结肠内重新分布；5)粘液层增多 血清脱氨基酪氨酸(DAT)水平与免疫调节和韧性相关的PAC来源的MM 对抗病毒引起的炎症。最后，我们证明了PAC，足以增加肠道 大量的粘液嗜酸杆菌。我们的数据表明PAC诱导的肠道环境改变促进了 新陈代谢韧性。为了建立因果关系，我们建议：1)将尿液/血液代谢物联系起来 使用在补充GP的人的纵向研究中收集的样本进行肠道细菌菌株/物种的研究 和PAC处理的小鼠，同时监测HFD-和LOW-D的代谢和组织表型。 脂肪饮食(LFD)喂养的小鼠宿主；2)进行体外和无菌小鼠研究，以证实特定的 细菌分离/结合到特异性MM；3)在细胞检测中研究PAC来源的MM的生物活性 与糖代谢和B29单相关的GF小鼠模型相关的HFD诱导Mets/T2D。

Project Summary: This multidisciplinary proposal aims to define how proanthocyanidins (PACs), a major class of grape polyphenols (GPs), alter the intestinal milieu to promote a biological signature associated with resilience to metabolic syndrome (MetS) and type-2 diabetes (T2D). Using urine, blood, and gut microbiota samples from PAC-supplemented mice and GP-supplemented humans, microbiome-wide association studies will be performed to correlate changes in bacterial strains/species to increases/decreases in microbial metabolites (MMs). PAC treatment of bacteria in vitro and of germfree mice inoculated with bacterial isolates or defined consortia will establish relationships between specific commensal bacteria and PAC-derived MMs, which will then be tested for bioactivity in mammalian cell culture assays and a high-fat diet (HFD)-induced mono- associated germfree (GF) model of MetS/T2D. PACs are associated with metabolic resilience; however, mechanism(s) of systemic protection have remained elusive due to generally poor absorption and uncertainty about molecular targets. PACs reach the colon where they are biotransformed to MM with greater bioavailability; however, the specific bacteria responsible for these transformations, the molecular targets of resulting MM, and validation of their efficacy in preclinical models of MetS/T2D remain to be investigated. We observed that GP supplementation can induce a bloom in the mucolytic gut bacterium Akkermansia muciniphila in association with reduced serum lipopolysaccharide, less intestinal and systemic inflammation, increased expression of tight junction protein occludin, improved glucose metabolism, and less adiposity and weight gain in HFD-fed mice. Increased abundance of A. muciniphila has been observed after gastric bypass surgery and metformin treatment, underlining its importance in positive metabolic outcomes. GP-supplemented mice also showed: 1) decreased bacterial community richness; 2) alterations in genera consistent with improved gut barrier integrity and lactic acid-production; 3) decreased serum levels of bacterial-derived secondary bile acids; 4) decreased thickness of the mucus layer adjacent to the intestinal epithelium with redistribution of mucus in the colon; and 5) increased serum levels of desaminotyrosine (DAT), a PAC-derived MM associated with immune modulation and resilience against virus-induced inflammation. Finally, we showed that PACs, are sufficient to increase intestinal abundance of A. muciniphila. Our data suggest PAC-induced alterations of the intestinal milieu promote metabolic resilience. To establish cause-effect relationships we propose to: 1) correlate urine/blood metabolites with gut bacterial strains/species using samples collected in longitudinal studies of GP-supplemented humans and PAC-treated mice with concomitant monitoring of metabolic and histological phenotypes in HFD- and low- fat diet (LFD)-fed murine hosts; 2) perform in vitro and germfree mouse studies to confirm relationship of specific bacteria isolate/consortia to specific MM; 3) investigate bioactivities of PAC-derived MM in cell-based assays related to glucose metabolism and the B29-monoassociated GF mouse model of HFD-induced MetS/T2D.