BACKGROUND:Consistent evidence suggests diabetes-protective effects of dietary fiber intake. However, the underlying mechanisms, particularly the role of gut microbiota and host circulating metabolites, are not fully understood. We aimed to investigate gut microbiota and circulating metabolites associated with dietary fiber intake and their relationships with type 2 diabetes (T2D).METHODS:This study included up to 11 394 participants from the HCHS/SOL (Hispanic Community Health Study/Study of Latinos). Diet was assessed with two 24-hour dietary recalls at baseline. We examined associations of dietary fiber intake with gut microbiome measured by shotgun metagenomics (350 species/85 genera and 1958 enzymes; n=2992 at visit 2), serum metabolome measured by untargeted metabolomics (624 metabolites; n=6198 at baseline), and associations between fiber-related gut bacteria and metabolites (n=804 at visit 2). We examined prospective associations of serum microbial-associated metabolites (n=3579 at baseline) with incident T2D over 6 years.RESULTS:We identified multiple bacterial genera, species, and related enzymes associated with fiber intake. Several bacteria (eg, Butyrivibrio, Faecalibacterium) and enzymes involved in fiber degradation (eg, xylanase EC3.2.1.156) were positively associated with fiber intake, inversely associated with prevalent T2D, and favorably associated with T2D-related metabolic traits. We identified 159 metabolites associated with fiber intake, 47 of which were associated with incident T2D. We identified 18 of these 47 metabolites associated with the identified fiber-related bacteria, including several microbial metabolites (eg, indolepropionate and 3-phenylpropionate) inversely associated with the risk of T2D. Both Butyrivibrio and Faecalibacterium were associated with these favorable metabolites. The associations of fiber-related bacteria, especially Faecalibacterium and Butyrivibrio, with T2D were attenuated after further adjustment for these microbial metabolites.CONCLUSIONS:Among United States Hispanics/Latinos, dietary fiber intake was associated with favorable profiles of gut microbiota and circulating metabolites for T2D. These findings advance our understanding of the role of gut microbiota and microbial metabolites in the relationship between diet and T2D.

中文翻译：

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与纤维摄入和 2 型糖尿病相关的肠道微生物群和血液代谢物


背景：一致的证据表明膳食纤维摄入具有糖尿病保护作用。然而，其潜在机制，特别是肠道微生物群和宿主循环代谢物的作用，尚未完全了解。我们的目的是调查与膳食纤维摄入相关的肠道微生物群和循环代谢物及其与 2 型糖尿病 (T2D) 的关系。 方法：这项研究包括来自 HCHS/SOL（西班牙社区健康研究/拉丁裔研究）的多达 11 394 名参与者。通过基线时两次 24 小时饮食回忆来评估饮食。我们检查了膳食纤维摄入量与通过鸟枪法宏基因组学测量的肠道微生物组（350种/85属和1958种酶；第2次访视时n = 2992）、通过非靶向代谢组学测量的血清代谢组学（624种代谢物；基线时n = 6198）和纤维相关肠道细菌和代谢物之间的关联（第 2 次访视时 n=804）。我们研究了 6 年来血清微生物相关代谢物（基线时 n=3579）与 T2D 事件之间的前瞻性关联。结果：我们确定了与纤维摄入相关的多个细菌属、物种和相关酶。几种参与纤维降解的细菌（例如丁酸弧菌、粪杆菌）和酶（例如木聚糖酶 EC3.2.1.156）与纤维摄入呈正相关，与流行的 T2D 呈负相关，并与 T2D 相关的代谢特征呈正相关。我们确定了 159 种与纤维摄入相关的代谢物，其中 47 种与 T2D 相关。我们鉴定了这 47 种代谢物中的 18 种与已确定的纤维相关细菌相关，包括几种与 T2D 风险呈负相关的微生物代谢物（例如吲哚丙酸和 3-苯基丙酸）。 丁酸弧菌和粪杆菌都与这些有利的代谢物相关。在对这些微生物代谢物进行进一步调整后，纤维相关细菌（尤其是粪杆菌和丁酸弧菌）与 T2D 的关联减弱。结论：在美国西班牙裔/拉丁裔中，膳食纤维摄入量与 T2D 的肠道微生物群和循环代谢物的有利特征相关。 。这些发现增进了我们对肠道微生物群和微生物代谢物在饮食与 T2D 之间关系中的作用的理解。