OBJECTIVES: To investigate the causal relationship between gut microbiota and kidney stones. METHODS: Mendelian randomization analysis was conducted based on data from the MiBioGen consortium gut microbiota GWAS (exposure factors) and the IEU Open GWAS kidney stone dataset ukb-b-8297 (outcome variables) using the inverse variance weighted, MR-Egger regression, weighted median, weighted mode, and simple mode methods. Heterogeneity, pleiotropy, and leave-one-out sensitivity analyses were also performed. In the animal experiment, 12 male SD rats were randomized into control group with saline treatment and kidney stone model group treated with 1% ethylene glycol and 2% ammonium chloride for 28 consecutive days. Urine, blood, and intestinal samples of the rats were collected for testing the changes in renal function and intestinal barrier-related indicators, and kidney and colon pathologies were examined with histological staining and immunohistochemistry. The changes in diversity and abundance of gut microbiota were analyzed using 16S rRNA gene sequencing. RESULTS: Mendelian randomization analysis showed that decreased abundances of Lachnospiraceae NK4A136 group (OR=0.9974, 95% CI: 0.9948-0.9999, P=0.0393) and Gordonibacter (OR=0.9987, 95% CI: 0.9974-0.9999, P=0.0403) were associated with an increased risk of kidney stones without significant heterogeneity or horizontal pleiotropy, and sensitivity analyses suggested robustness of the results. The rat models of kidney stones exhibited significant renal function impairment and calcium oxalate crystal deposition, accompanied by decreased expressions of intestinal barrier-related proteins with lowered intestinal α- and β-diversity indices. Intestinal Gordonibacter abundance was significantly reduced in the rat models while the Lachnospiraceae NK4A136 group did not differ significantly between the control and model groups. CONCLUSIONS Decreased Gordonibacter abundance in gut microbiota is associated with an increased risk of kidney stones. The protective role of the Lachnospiraceae NK4A136 group against kidney stones as suggested by Mendelian randomization analysis fails to be supported by the experimental evidence and awaits further investigation.
Animals ; Kidney Calculi/microbiology* ; Gastrointestinal Microbiome ; Mendelian Randomization Analysis ; Rats, Sprague-Dawley ; Rats ; Male ; Disease Models, Animal ; Intestines/microbiology* ; RNA, Ribosomal, 16S/genetics*

OBJECTIVESTo analyze the pathogenic bacterial's distribution and the drug resistance in the upper urinary tract stones, and to provide the information for choosing suitable antibiotics.

METHODSStone samples were taken for culture and for drug sensitivity test in 146 patients undergoing percutaneous nephrolithotomy between April 2007 and October 2008, and the results were analyzed.

RESULTSPathogens presented in 72 (49.3%) patients. There were 70 (86.4%) Gram-negative bacteria strains. Escherichia coli, Pseudomonas aeruginosa and Enterobacter cloacae were the predominant bacteria, accounted for 30.9%(25 strains), 23.5% (19 strains) and 12.3% (10 strains), respectively. There were 10 (12.3%) Gram-positive bacteria strains, the predominant bacteria was Staphylococcus epidermidis (6 strains), accounting for 7.4%. And there was 1 fungi strain (1.2%). Resistance to ampicillin/sulbactam (88.7%), ceftriaxone (81.3%) and ciprofloxacin (67.5%) was most commonly found in pathogen, and the rate of resistance to amikacin, imipenem and piperacillin/tazobactam were 8.6%, 10.0%, 10.0%, respectively. Erythromycylamine, teicoplanin, SMZ-TMP, nitrofurantoin were sensitive to Gram-positive bacteria.

CONCLUSIONSBacterial's distribution of upper urinary tract stones are multiple, and the majority pathogen is Gram-negative bacteria. A big variant resistance is found among different bacterium. The suitable antibiotics should be chosen according to the different bacterium in the patients who underwent percutaneous nephrolithotomy.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Bacteria ; drug effects ; isolation & purification ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Humans ; Kidney Calculi ; microbiology ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Retrospective Studies ; Ureteral Calculi ; microbiology ; Young Adult

OBJECTIVENanobacteria, a new kind of bacteria found by a Finnish scholar, is considered to relate to many human diseases like nephrolithiasis. However, there are no data available on nanobacteria infection in Chinese people.

METHODSNanobacteria was detected in serum of 336 cases of healthy adults in Southern China by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry stain. The monoclonal antibody of nanobacterum was supplied by Kuipio University of Finland.

RESULTSNanobacteria infection rates were 27 (8.0%), 19 (5.7%) in the healthy adults by ELISA and immunohistochemistry stain respectively. No difference was shown between the 2 methods and between male and female, statistically. Age and sex did not seem to be related to the infectious risk of nanobacteria. However, the infectious rate was lower in those below 30-year-old than that of people over 60-year-old (P < 0.05).

CONCLUSIONNanobacteria was existed in the serum of Chinese healthy people with an infectious rate of 8.0%.

Adult ; Arteriosclerosis ; microbiology ; China ; epidemiology ; Enzyme-Linked Immunosorbent Assay ; Female ; Gram-Negative Bacteria ; isolation & purification ; Gram-Negative Bacterial Infections ; blood ; epidemiology ; microbiology ; Humans ; Immunohistochemistry ; Kidney Calculi ; microbiology ; Male