Effects of Resistant Starch Diet on the Gut Microbiome in Chronic Kidney Disease

University of Arkansas

Status: Completed

Conditions: Chronic Kidney Diseases

Treatments: Dietary Supplement: Resistant Starch

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT03356990

206708

1P20GM121293 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

The investigators want to learn more about how to help people who have chronic kidney disease (CKD). This study will increase the investigators understanding of how diet affects factors that can slow the progression of kidney disease. The investigators are asking 30 adults and 30 children with stage 3 CKD to be part of this study. Participants will supplement their diet with resistant starch for two weeks. The investigators anticipate that the resistant starch will change the bacteria in the intestines to a more beneficial type of bacteria. The investigators will measure a product of these beneficial bacteria called butyrate. The investigators will also determine changes in the gut bacteria and products of the bacteria in the blood.

Full description

Chronic kidney disease (CKD), a progressive decline in kidney function, is a growing health problem: 13% of adults in the US have CKD. Among patients with CKD, the risk of progression to irreversible loss of kidney function (end-stage renal disease, ESRD) is about 1% per year. In addition, adjusted mortality is approximately four times greater among those with CKD compared to those without. For ESRD, apart from dialysis and kidney transplant, no treatment exists. CKD increases urea levels in bodily fluids leading to a dominance of urease-containing bacteria in the gut. Such dysbiosis results in decreased production of the short chain fatty acid, butyrate and decreased health of the colonic epithelial barrier. Consequently, bacterial toxins translocate into the bloodstream, promoting inflammation. Moreover, production of uremic toxins such as indoxyl and p-cresyl sulfates are also increased, resulting in further kidney injury.

CKD patients are prescribed a diet low in protein, fiber and symbiotic organisms, which reduces complications like hyperkalemia, but also contributes to the dysbiosis. Re-formulating the CKD diet may improve the clinical management of CKD. The investigators's overall hypothesis is that changes in the microbial diversity, xeno-proteins and xeno-metabolites correlate with CKD progression, and microbiome-directed therapies can be used to slow the disease. In this study, the investigators will determine the tolerability of supplemental resistant starch (RS). Secondary aims are to determine if a diet high in resistant starch changes fecal butyrate concentrations, the make-up of the gut microbiome and the concentrations in the blood of uremic toxins produced by the gut microbiome. This study will help in the design of a future study with the aim of understanding if a high resistant starch diet can slow the progression of chronic kidney disease.

Enrollment: 19 patients

Sex: All

Ages: 5 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adult

  • Between the ages of 18 and 85 years old
  • Glomerular filtration rate estimated by creatinine clearance (eGFR Cr):between 59 and 30 ml/min for stage 3 CKD patients
  • Urine protein < 1 gram per day by 24-hour protein collection or urine protein-to-creatinine ratio <1 gram/gram or urine microalbumin to creatinine concentration less than 1000 mg/g.

• Children

  • Between the ages of 5 and 17 years
  • eGFR Cr between 30 and 59 (stage 3 CKD) using the revised Schwartz equation.
  • Urine protein < 1 gram per day by 24-hour protein collection or urine protein-to-creatinine ratio <1 gram/gram.

Exclusion criteria

Adult

• Age older than 85 years
• eGFR Cr > 59 ml/min or < 30 ml/min
• History of renal transplant
• Subject with diabetes (as defined by patient report, taking medications for the treatment of diabetes or as reported in the medical record)
• Use of antibiotics within 1 month
• Use of laxatives within 1 month
• Inflammatory bowel disease
• Irritable bowel syndrome
• Colorectal cancer
• Surgically removed bowel or presence of an ostomy
• Pregnancy
• Inability to obtain written informed consent
• Constipation
• Diarrhea

Children

• Age younger than 5 years
• eGFR > 59 ml/min and < 30 ml/min
• History of renal transplant
• Subject with diabetes (as defined by patient report, taking medications for the treatment of diabetes or as reported in the medical record)
• Use of antibiotics within 1 month
• Use of laxatives within 1 month
• Inflammatory bowel disease
• Surgically removed bowel or presence of an ostomy
• Pregnancy
• Constipation
• Diarrhea

Trial design

Primary purpose: Prevention

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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19 participants in 1 patient group

Resistant Starch

Experimental group

Description:

Intervention: Dietary supplement will be taken every day for total of 2 weeks. Each participant will be take half the dose of Hi-Maze 260 or "High RS Gummy Chews" in the morning and the other half dose in the evening Adult participants are asked to introduce in their diet 30 grams of high RS supplement each day of the diet period (2 weeks). Children of age included between 5 and 9 years are asked to introduce in their diet 10 grams of high RS supplement each day of the diet period (2 weeks). Children of age included between 10 and 17 years are asked to introduce in their diet 15 grams of high RS supplement each day of the diet period (2 weeks).

Treatment:

Dietary Supplement: Resistant Starch