Sirich Tammy L, Plummer Natalie S, Gardner Christopher D, Hostetter Thomas H, Meyer Timothy W
Departments of Medicine, Veterans Affairs Palo Alto Health Care System and Stanford University, Palo Alto, California; and
Departments of Medicine, Veterans Affairs Palo Alto Health Care System and Stanford University, Palo Alto, California; and.
Clin J Am Soc Nephrol. 2014 Sep 5;9(9):1603-10. doi: 10.2215/CJN.00490114. Epub 2014 Aug 21.
Numerous uremic solutes are derived from the action of colon microbes. Two such solutes, indoxyl sulfate and p-cresol sulfate, have been associated with adverse outcomes in renal failure. This study tested whether increasing dietary fiber in the form of resistant starch would lower the plasma levels of these solutes in patients on hemodialysis.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Fifty-six patients on maintenance hemodialysis were randomly assigned to receive supplements containing resistant starch (n=28) or control starch (n=28) daily for 6 weeks in a study conducted between October 2010 and May 2013. Of these, 40 patients (20 in each group) completed the study and were included in the final analysis. Plasma indoxyl sulfate and p-cresol sulfate levels were measured at baseline and week 6.
Increasing dietary fiber for 6 weeks significantly reduced the unbound, free plasma level of indoxyl sulfate (median -29% [25th percentile, 75th percentile, -56, -12] for fiber versus -0.4% [-20, 34] for control, P=0.02). The reduction in free plasma levels of indoxyl sulfate was accompanied by a reduction in free plasma levels of p-cresol sulfate (r=0.81, P<0.001). However, the reduction of p-cresol sulfate levels was of lesser magnitude and did not achieve significance (median -28% [-46, 5] for fiber versus 4% [-28, 36] for control, P=0.05).
Increasing dietary fiber in hemodialysis patients may reduce the plasma levels of the colon-derived solutes indoxyl sulfate and possibly p-cresol sulfate without the need to intensify dialysis treatments. Further studies are required to determine whether such reduction provides clinical benefits.
众多尿毒症溶质源自结肠微生物的作用。其中两种溶质，硫酸吲哚酚和对甲酚硫酸酯，与肾衰竭的不良后果相关。本研究检测了以抗性淀粉形式增加膳食纤维是否会降低血液透析患者血浆中这些溶质的水平。
设计、地点、参与者及测量方法：在2010年10月至2013年5月进行的一项研究中，56例维持性血液透析患者被随机分配，每天接受含抗性淀粉的补充剂（n = 28）或对照淀粉（n = 28），为期6周。其中，40例患者（每组20例）完成了研究并纳入最终分析。在基线和第6周时测量血浆硫酸吲哚酚和对甲酚硫酸酯水平。
增加膳食纤维6周显著降低了硫酸吲哚酚的未结合、游离血浆水平（膳食纤维组中位数为-29%[第25百分位数，第75百分位数，-56，-12]，对照组为-0.4%[-20，34]，P = 0.02）。硫酸吲哚酚游离血浆水平的降低伴随着对甲酚硫酸酯游离血浆水平的降低（r = 0.81，P < 0.001）。然而，对甲酚硫酸酯水平的降低幅度较小且未达到显著水平（膳食纤维组中位数为-28%[-46，5]，对照组为4%[-28，36]，P = 0.05）。
增加血液透析患者的膳食纤维可能会降低源自结肠的溶质硫酸吲哚酚以及可能的对甲酚硫酸酯的血浆水平，而无需强化透析治疗。需要进一步研究以确定这种降低是否具有临床益处。
