The gut microbiota profile of adults with kidney disease: A systematic review of the literature

Abstract

Background There is mounting evidence that individuals with kidney disease have an abnormal gut microbiota composition. No studies to date have summarised the evidence to categorise how the gut microbiota profile of individuals with kidney disease may differ from healthy controls. Synthesis of this evidence is important to inform future clinical trials. This systematic review aims to characterise differences of the gut microbiota composition in adults with kidney disease, as well as to describe the functional capacity of the gut microbiota and reporting of diet as a confounder in these studies. Methods Included studies were those that investigated the gut microbial community in adults with any type of kidney disease and compared this to the profile of healthy controls. Six scientific databases (CINHAL, Medline, PubMed, Scopus, Web of Science, Cochrane Library) as well as selected grey literature sources were searched up until August 2018. Quality assessment was undertaken independently by three authors. The system of evidence level criteria was employed to quantitatively evaluate the alteration of microbiota by strictly considering the number, methodological quality and consistency of the findings. Additional findings relating to altered functions of the gut microbiota, dietary intakes and dietary methodologies used were qualitatively summarised. Results Sixteen articles, reporting 15 studies met the eligibility criteria and included a total of 540 adults with kidney disease and 1117 healthy controls. Compared to healthy controls, individuals with kidney disease had increased abundances of Enterobacteriaceae, and decreased abundances of Coprococcus and Prevotella. Adults with kidney stones also had an altered microbial composition with variations to Bacteroides, Lachnospiraceae NK4A136 group, Ruminiclostridium 5 group, Dorea, Enterobacter, Christensenellaceae and its genus Christensenellaceae R7 group. Altered microbial functions in adults with kidney disease were reported, particularly in the context of metabolic pathways relating to urea and uremic toxin generation. Only three of the 16 articles accounted for diet, and of these studies only two used a valid dietary assessment method. Conclusions The gut microbiota profile of adults with kidney disease differs from healthy controls. Future study designs should include adequate reporting of important confounders such as dietary intakes to assist with interpretation of findings.

Urinary Microbial and Metabolomic Profiles in Kidney Stone Disease

“…In recent years, the microbiome has been shown to be involved in maintaining homeostasis and pathological processes of disease. Traditionally, the urinary system is considered sterile, and previous studies of nephrolithiasis have focused more on the gut microbiome (Liu et al, 2020b;Stanford et al, 2020). Observations from these previous studies have identified substantial differences in gut microbiota compositions between healthy individuals and nephrolithiasis patients (Stern et al, 2016).…”