Urobiota and urinary tract infections in liver cirrhosis

The urobiome is being actively studied, diagnostics are being improved and new markers of inflammatory diseases of the urinary tract are being searched for, despite the fact that most microorganisms are unidentified and their functions remain not fully understood. The aim of the study was to study the composition of the urinary tract microbiota (urobiota) in patients with liver cirrhosis, depending on the presence of urinary tract infection. Material and methods. A prospective cohort single-center study was conducted on 48 patients with liver cirrhosis (30 men, 18 women), who, in addition to standard studies, underwent metagenomic sequencing of urine and feces. The average age of the examined patients was 50.5 years, there were 16 and 32 patients with and without urinary tract infection, respectively. High-performance sequencing was performed using the MiSeq genetic analyzer (Illumina, USA) using a protocol based on the analysis of variable regions of the 16s rRNA gene. Data analysis was performed using the Kraken2 algorithm. The significance level of α is assumed to be 0.05. The study is registered in Clinicaltrials.gov (NCT05335213). The results and their discussion. The dominant phylotypes of the urobiota in patients with liver cirrhosis are Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, among which Proteobacteria predominate (more than 50 %). The beta diversity of the urinary tract microbiota has significant differences in patients without or with urinary tract infection (p = 0.001). Urinary tract infection increases the density of such taxa in urine as Gammaproteobacteria, including Escherichia, Klebsiella, Acinetobacter, Enterobacter, as well as Bacilli, Synergistia, Deltaproteobacteria, Epsilonproteobacteria, Acidithiobacillia and decreases the density of Prevotella, Clostridioides, Brevundimonas, Delftia, Stenotrophomonas, Streptococcus (p < 0.05). Conclusions. Microbiological identification based on the method of metagenomic sequencing made it possible to identify more than 1,000 types of microorganisms in the urine of patients with liver cirrhosis, including uncultivated ones, and a characteristic bacterial pattern of urinary tract infection, which expands the understanding of the pathogenesis and diagnostic possibilities of urinary tract infections and creates prerequisites for substantiating the directions of microbiota modulation and personalization of patient treatment.