背景:短链脂肪酸(SCFA),主要是醋酸盐,丙酸和丁酸,由肠道微生物群通过发酵不能被人类宿主消化的复杂碳水化合物产生。它们影响肠道健康,并且可以在远端水平上促进几种疾病的病理生理学,包括肾脏病变。
方法:在慢性肾脏病(CKD)患者(n=54)的不同疾病阶段测量SCFA水平,并检查其与肾功能和炎症参数的关系。使用全基因组表达测定分析丙酸和丁酸在炎症条件下在肾小管细胞中触发的途径中的影响。最后,叶酸诱导急性肾损伤转化为CKD的临床前小鼠模型用于分析这些微生物代谢产物在CKD发展过程中的预防和治疗潜力.
结果:CKD患者粪便中丙酸盐和丁酸盐水平随着病情的进展逐渐降低,并与已建立的血清肌酐临床参数密切相关,血尿素氮和估计的肾小球滤过率。丙酸盐和丁酸盐共同下调肾小管细胞中与TNF-α触发的炎症过程和免疫系统激活相关的103个基因的表达。在体内,丙酸和丁酸的管理,在受伤前或受伤后不久,分别防止和减缓损害的发展。肾损伤标志物的减少表明了这一点,促炎和促纤维化标志物的表达,和长期肾功能的恢复。
结论:丙酸盐和丁酸盐水平与CKD患者肾功能的进行性丧失有关。早期给予这些SCFA可防止急性肾损伤临床前模型中的疾病进展,证明它们的治疗潜力独立于肠道微生物群。
BACKGROUND: Short-chain fatty acids (SCFAs), mainly acetate, propionate and butyrate, are produced by gut microbiota through fermentation of complex carbohydrates that cannot be digested by the human host. They affect gut health and can contribute at the distal level to the pathophysiology of several diseases, including renal pathologies.
METHODS: SCFA levels were measured in chronic kidney disease (CKD) patients (n = 54) at different stages of the disease and associations with renal function and inflammation parameters were examined. The impact of propionate and butyrate in pathways triggered in tubular cells under inflammatory conditions was analysed using genome-wide expression assays. Finally, a pre-clinical mouse model of folic acid-induced transition from acute kidney injury to CKD was used to analyse the preventive and therapeutic potential of these microbial metabolites in the development of CKD.
RESULTS: Faecal levels of propionate and butyrate in CKD patients gradually reduce as the disease progresses, and do so in close association with established clinical parameters for serum creatinine, blood urea nitrogen and the estimated glomerular filtration rate. Propionate and butyrate jointly downregulated the expression of 103 genes related to inflammatory processes and immune system activation triggered by TNF-α in tubular cells. In vivo, the administration of propionate and butyrate, either before or soon after injury, respectively prevented and slowed the progression of damage. This was indicated by a decrease in renal injury markers, the expression of pro-inflammatory and pro-fibrotic markers, and recovery of renal function over the long term.
CONCLUSIONS: Propionate and butyrate levels are associated with a progressive loss of renal function in CKD patients. Early administration of these SCFAs prevents disease advancement in a pre-clinical model of acute renal damage, demonstrating their therapeutic potential independently of the gut microbiota.