Design and rationale for an open-label, randomized, controlled pilot trial to evaluate the changes in blood uremic toxins in patients with chronic kidney disease by dietary therapy with sake lees

Clin Exp Nephrol. 2024 May;28(5):440-446. doi: 10.1007/s10157-023-02450-x. Epub 2024 Feb 10.

Abstract

Background: Patients with chronic kidney disease (CKD) reportedly show dysbiosis, which is the imbalance of gut microbiome. Dysbiosis increases the uremic toxin level in the intestine, and uremic toxins transfer into the blood, causing CKD progression. Sake lees, a traditional Japanese fermented food, may help reduce uremic toxins by altering the gut microbiome. Additionally, D-alanine, which is present in sake lees, may have a renoprotective effect. The present pilot study aims to evaluate the effect of adding sake lees to the standard CKD dietary therapy in reducing blood uremic toxins.

Methods: This pilot study is a single-center, open-label, randomized controlled trial. Twenty-four patients with CKD will be enrolled and allocated 1:1 to the intervention and control groups. The intervention group will receive standard CKD dietary therapy with an additional intake of 50 g of sake lees per day for 8 weeks, whereas the control group will only receive standard CKD dietary therapy. The primary endpoint is the change in serum indoxyl sulfate after 8 weeks. The secondary endpoint is the plasma D-alanine and fecal microbiome changes.

Conclusion: This pilot study provides insight into the development of a new diet focused on gut microbiome and D-amino acids in patients with CKD.

Clinical trial registration: This protocol was approved by the Clinical Trial Review Board of Kanazawa University Hospital on October 27, 2022 (2022-001 [6139]) and available to the public on the website of the Japan Registry of Clinical Trials on November 22, 2022 (jRCT1040220095).

Keywords: Chronic kidney disease; D-amino acids; Dysbiosis; Sake lees; Uremic toxins.

Publication types

  • Clinical Trial Protocol

MeSH terms

  • Adult
  • Aged
  • Dysbiosis
  • Female
  • Fermented Foods
  • Gastrointestinal Microbiome*
  • Humans
  • Male
  • Middle Aged
  • Pilot Projects
  • Randomized Controlled Trials as Topic
  • Renal Insufficiency, Chronic* / blood
  • Renal Insufficiency, Chronic* / complications
  • Renal Insufficiency, Chronic* / diet therapy
  • Renal Insufficiency, Chronic* / therapy
  • Uremic Toxins* / blood

Substances

  • Uremic Toxins