Evaluation of Gut Bacteria in Patients With Polycystic Kidney Disease

Studies have shown that gut microbes can influence numerous aspects of human biology, and
alterations in the function and composition of gut microbial flora (microbiota) play a major
role in the pathogenesis of diverse human illnesses such as chronic inflammation, diabetes
mellitus, and cardiovascular diseases. Gut microbes provide protection against pathogenic
organisms, contribute to energy metabolism, serve a clear role in the development and
modulation of the human gut immune system, and participate in nitrogen and micronutrient
homeostasis by synthesizing amino acids and various vitamins. However, whether the
composition of gut microbes is altered in human with renal failure has not been clearly
demonstrated. Furthermore, whether alterations in the gut microbiota due to renal failure
contribute to development of co-morbid conditions associated with CKD has never been
examined. There are several lines of evidence to suggest that the gut microbiota is likely
altered in patients with CKD. It has been established that protein assimilation in the small
intestine is impaired in CKD .

To examine the impact of renal failure on the composition of gut microbiota we are studying
patients with renal failure due to polycystic kidney disease (PKD). PKD is the fourth
leading cause of kidney failure, and is the most common genetic kidney disease. Compared to
patients with renal failure due to diabetic nephropathy, hypertension, and
glomerulonephritis, patients with PKD have virtually no major co-morbid medical conditions
or associated medical interventions (i.e. antimicrobial or anti-inflammatory therapies) that
could potentially alter the gut microbiota, and confound the interpretation of data.

Objectives

1. To compare the gut microbiota in fecal samples of PKD patients with different degrees
of renal disease.

2. To determine whether alteration in the composition of gut microbiota is linked to serum
levels of metabolites and uremic solutes that are known to be associated with symptoms
of uremia.

Inclusion Criteria:

- Age > 18 years.

- Patients with PKD.

- Patients are able to understand and give consent.

Exclusion Criteria:

- Patient on antibiotics or vitamin supplement (except vitamin D analogs) in the last
three months.

- Advanced liver disease, advanced cardiovascular disease, heart failure with EF < 30%,
and autoimmune disease.

- The use of chemotherapy, antibiotics, immunosuppressive medications, probiotics, and
steroid in the last three month.

- Intravenous or oral iron supplementation, laxatives, and kayexalate in the last
month.

- History of intra abdominal surgery, small or large intestine resection or small bowel
obstruction.

- History of colon cancer or gastrointestinal bleed.