ABSTRACT
Accumulated evidence shows that complex microbial communities resides in the healthy human urinary tract and can change in urological disorders. However, there lacks a comprehensive profiling of the genitourinary microbiota in healthy cohort. Here, we performed 16S rRNA gene sequencing of midstream urine specimens from 1,172 middle-aged and elderly healthy individuals. The core microbiota included 6 dominant genera (mean relative abundance >5%), including Prevotella, Streptococcus, Lactobacillus, Gardnerella, Escherichia-Shigella, and Veillonella, and 131 low-abundance genera (0.01-5%), displaying a distinct microbiome profiles to that of host-matched gut microbiota. The composition and diversity of genitourinary microbiome (GM) were distinct between genders and may fluctuate with ages. Several urotypes were identified by the stratification of microbiome profiles, which were mainly dominated by the six most predominant genera. The prevalence of urotypes was disparate between genders, and the male sample additionally harbored other urotypes dominated by Acinetobacter, Corynebacterium, Staphylococcus, or Sphingomonas. Peptoniphilus, Ezakiella, and Porphyromonas were co-occurred and co-abundant, and they may play crucial roles as keystone genera and be associated with increased microbial diversity. Our results delineated the microbial structure and diversity landscape of the GM in healthy middle-aged and elderly adults and provided insights into the influence of gender and age to it.
ABSTRACT
Human microbiome understanding and its relationship with health has represented a revolution in biomedicine, facilitated by the emergence of new molecular microbiology techniques. Lithiasic pathology has not been alien to this new approach to etiological knowledge. As a result of this research activity, it has been possible to elucidate the importance of the intestine-kidney axis, understood as the impact of the intestinal microbiota on nephrourinary health. In this regard the ability to use oxalate as an energy source by certain intestinal microorganisms has been used as a target form odulators of the intestinal microbiota in order to correcthyperoxaluria, both primary and secondary. However,the importance of the microbiome configuration, and its role in oxalocalcic lithiasis, transcends the existence of certain trophic networks. In particular, intestinal microbiome has the ability to promote tubular lesions resulting from oxidative stress caused by chronic low-grade inflammation, closely linked to the composition of the microbiota and the dialogue established with the immune system at the intestinal level. The importance of the urobiome, a stable microbia lstructure residing in the urinary tract, allowed to calibrate the importance of urinary microorganisms in lithiasic pathology, breaking with the paradigm of urine sterility in healthy conditions. Thus, recent studies suggest that the composition and structure of the urobiome have a crucial impact on infectious but also non-infectious lithiasis, since certain microorganisms can act as nucleants and promoters of the lithogenic process. Associated with the advances in the study of binomial microbiota and lithiasic pathology, new ways are opened for patient management, in terms of prevention and treatment, based on intervention on the microbiome. Future therapeutic arsenal, in addition to probiotics and prebiotics, will integrate consortia of different microbial groups and microbiota transplantation, both urinary and intestinal.
El desarrollo del conocimiento del microbioma humano y su relación con la salud ha representado una revolución en el ámbito biomédico, gracias a la eclosión de nuevas técnicas de microbiología molecular. La patología litiásica no ha sido ajena a esta nueva aproximación al conocimiento etiológico. Fruto de esta actividad investigadora se ha podido elucidar la importancia del eje intestino-riñón, entendido como elimpacto de la microbiota intestinal sobre la salud nefrourinaria. En este sentido, la capacidad de utilizar oxalato como fuente de energía por parte de determinados microorganismos intestinales, ha sido utilizado como diana de actuación de moduladores de la microbiota intestinal con el fin de corregir hiperoxalurias, tanto primarias como secundarias. No obstante, la importancia de la configuración del microbioma, y su rol en la litiasis oxalocálcica, transciende la existencia de determinadas redes tróficas. Particularmente, estado disbióticos de la microbiota tienen la capacidad de promover lesiones tubulares fruto del estrés oxidativo originado por la inflamación crónica de bajo grado, íntimamente ligada con la composición de la microbiota y el diálogo establecido con el sistema inmunitario a nivel intestinal. La descripción del urobioma, entendido como la estructura ecológica microbiana estable que reside en las vías urinarias, además de romper con el paradigma de la esterilidad de la orina en ausencia de infección, ha permitido calibrar la importancia real de los microorganismos que lo componen en la patología urolitiásica. Así, existen trabajos que apuntan a que composición y estructura del urobioma impactará de forma crucial en lalitiasis infecciosa pero también en la no infecciosa, en tanto determinados microorganismos tienen la capacidad de actuar como nucleantes y promotores del proceso litogénico. Asociado al ingente desarrollo del conocimientoen el binomio microbiota y patología litiásica se abren nuevas vías para el manejo del paciente, tanto en términos de prevención como de tratamiento, basados en la intervención sobre el microbioma. Entre el arsenal terapéutico futuro, además de los probióticos y prebióticos, con total seguridad se encontraran los consorcios de diferentes grupos microbianos, así como el trasplantede microbiota, tanto intestinal como urinaria.
Subject(s)
Gastrointestinal Microbiome , Lithiasis , Probiotics , Urinary Tract , Humans , PrebioticsABSTRACT
BACKGROUND: The urinary microbiota is similarly complex as the vaginal and penile microbiota, yet its role as a reservoir for pathogens and for recurrent polymicrobial biofilm diseases like bacterial vaginosis (BV) is not clear. RESULTS: Here, we analysed the urinary microbiota of healthy men and women and compared it with that of women during BV and after antibiotic treatment using next-generation sequencing of the 16S rRNA gene V1-V2 regions. Eight different community types, so called urotypes (UT), were identified in healthy humans, all of which were shared between men and women, except UT 7, dominated in relative abundance by Lactobacillus crispatus, which was found in healthy women only. Orally applied metronidazole significantly reduced Shannon diversity and the mean relative abundance of Gardnerella vaginalis, Atopobium vaginae, and Sneathia amnii, while L. iners increased to levels twofold higher than those found in healthy women. Although individual urine microbial profiles strongly responded to the antibiotic, the healthy community could not be restored. The correlation between urinary and vaginal fluid microbiota was generally weak and depending on UT and BV status. It was highest in UT 1 in acute BV (59% of samples), but after metronidazole treatment, only 3 out of 35 women showed a significant correlation between their urinary and vaginal microbiota composition. CONCLUSIONS: Urethra and bladder thus harbor microbial communities distinct from the vagina. The high abundance of BV related species in the urine of both men and women suggests that urine may act as a reservoir of pathogens and contribute to recurrence. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02687789.