Willis Nathaniel B, Muñoz Colleen X, Mysonhimer Annemarie R, Edwards Caitlyn G, Wolf Patricia G, Hillman Charles H, Burd Nicholas A, Holscher Hannah D, Khan Naiman A
Division of Nutritional Science, University of Illinois at Urbana-Champaign, Champaign, Illinois, USA,
Department of Health Sciences, University of Hartford, West Hartford, Connecticut, USA.
Ann Nutr Metab. 2021;77 Suppl 4:37-45. doi: 10.1159/000520478. Epub 2022 Feb 28.
Prevalence of chronic hypohydration remains elevated among adults in the USA; however, the health effects of hypohydration in regards to human gut health have not been explored.
This study examined the relationship between total water intake, hydration biomarkers (first-morning urine specific gravity [FMUsg], first-morning urine volume [FMUvol], and plasma copeptin), fecal microbiota, and plasma lipopolysaccharide-binding protein (LBP) in adults (25-45 years, 64% female). Fecal microbiota composition was assessed using 16S rRNA gene sequencing (V4 region). Immunoassays quantified plasma copeptin and LBP in fasted venous blood samples. Dietary variables were measured using 7-day food records. Linear discriminant analysis effect size (LEfSe) analyzed differentially abundant microbiota based on median cutoffs for hydration markers. Multiple linear regressions examined the relationship between LBP and copeptin.
LEfSe identified 6 common taxa at the genus or species level that were differentially abundant in FMUsg, total water (g/day), or plasma copeptin (µg/mL) groups when split by their median values. Uncultured species in the Bacteroides, Desulfovibrio, Roseburia, Peptococcus, and Akkermansia genera were more abundant in groups that might indicate poorer hydration status. Multivariate linear analyses revealed a positive relationship between plasma copeptin and LBP when controlling confounding variables (F(6,52) = 4.45, p = 0.002, R2 = 0.34).
Taxa common between markers are associated with the intestinal mucus layer, which suggests a potential link between hydration status and intestinal mucus homeostasis. The relationship between LBP and copeptin indicates that copeptin may be sensitive to metabolic endotoxemia and potentially gut barrier function.
在美国成年人中，慢性水合不足的患病率仍然很高；然而，水合不足对人体肠道健康的影响尚未得到研究。
本研究调查了成年人（25 - 45岁，64%为女性）的总饮水量、水合生物标志物（晨尿比重[FMUsg]、晨尿体积[FMUvol]和血浆 copeptin）、粪便微生物群和血浆脂多糖结合蛋白（LBP）之间的关系。使用16S rRNA基因测序（V4区域）评估粪便微生物群组成。免疫测定法定量空腹静脉血样本中的血浆copeptin和LBP。使用7天食物记录测量饮食变量。线性判别分析效应大小（LEfSe）基于水合标记物的中位数临界值分析差异丰富的微生物群。多元线性回归研究了LBP和copeptin之间的关系。
LEfSe在属或种水平上鉴定出6个常见分类群，当按中位数划分时，它们在FMUsg、总水量（克/天）或血浆copeptin（微克/毫升）组中差异丰富。拟杆菌属、脱硫弧菌属、罗氏菌属、消化球菌属和阿克曼氏菌属中的未培养物种在可能表明水合状态较差的组中更为丰富。多变量线性分析显示，在控制混杂变量时，血浆copeptin和LBP之间存在正相关关系（F(6,52) = 4.45，p = 0.002，R2 = 0.34）。
标记物之间共有的分类群与肠道黏液层相关，这表明水合状态与肠道黏液稳态之间可能存在联系。LBP和copeptin之间的关系表明，copeptin可能对内毒素血症和潜在的肠道屏障功能敏感。
