Lactiplantibacillus plantarum J-15 reduced calcium oxalate kidney stones by regulating intestinal microbiota, metabolism, and inflammation in rats.

The prevention role of Lactiplantibacillus plantarum against the formation of kidney stones has been increasingly recognized; its mechanism, however, has mainly been focused on inhibiting the inflammation in the colon in the gastrointestinal (GI) system, and the intestinal metabolites from microflora have not been revealed fully with regarding to the stone formation. In this study, we investigated the effect of L. plantarum J-15 on kidney stone formation in renal calcium oxalate (CaOx) rats induced by ethylene glycol and monitored the changes of intestinal microflora and their metabolites detected by 16S rRNA sequencing and widely targeted analysis, followed by the evaluation of the intestinal barrier function and inflammation levels in the colon, blood and kidney. The results showed that L. plantarum J-15 effectively reduced renal crystallization and urinary oxalic acid. Ten microbial genera, including anti-inflammatory and SCFAs-related Faecalibaculum, were enriched in the J-15 treatment group. There are 136 metabolites from 11 categories significantly different in the J-15 supplementation group compared with CaOx model rats, most of which were enriched in the amino acid metabolic and secondary bile acid pathways. The expression of intestinal tight junction protein Occludin and the concentration of pro-inflammatory cytokines and prostaglandin were decreased in the intestine, which further reduced the translocated lipopolysaccharide and inflammation levels in the blood upon J-15 treatment. Thus, the inflammation and injury in the kidney might be alleviated by downregulating TLR4/NF-κB/COX-2 signaling pathway. It suggested that L. plantarum J-15 might reduce kidney stone formation by restoring intestinal microflora and metabolic disorder, protecting intestinal barrier function, and alleviating inflammation. This finding provides new insights into the therapies for renal stones.

Lactiplantibacillus plantarum Reduced Renal Calcium Oxalate Stones by Regulating Arginine Metabolism in Gut Microbiota.

Renal calcium oxalate (CaOx) stones are a common kidney disease. There are few methods for reducing the formation of these stones. However, the potential of probiotics for reducing renal stones has received increasing interest. We previously isolated a strain of Lactiplantibacillus plantarum N-1 from traditional cheese in China. This study aimed to investigate the effects of N-1 on renal CaOx crystal deposition. Thirty rats were randomly allocated to three groups: control group (ddH2O by gavage), model group [ddH2O by gavage and 1% ethylene glycol (EG) in drinking water], and Lactiplantibacillus group (N-1 by gavage and 1% EG in drinking water). After 4 weeks, compared with the model group, the group treated with N-1 exhibited significantly reduced renal crystals (P < 0.05). In the ileum and caecum, the relative abundances of Lactobacillus and Eubacterium ventriosum were higher in the control group, and those of Ruminococcaceae UCG 007 and Rikenellaceae RC9 were higher in the N-1-supplemented group. In contrast, the relative abundances of Staphylococcus, Corynebacterium 1, Jeotgalicoccus, Psychrobacter, and Aerococcus were higher in the model group. We also predicted that the arginase level would be higher in the ileal microbiota of the model group than in the N-1-supplemented group with PICRUSt2. The arginase activity was higher, while the level of arginine was lower in the ileal contents of the model group than in the N-1-supplemented group. The arginine level in the blood was also higher in the N-1-supplemented group than in the model group. In vitro studies showed that exposure to arginine could reduce CaOx crystal adhesion to renal epithelial HK-2 cells. Our findings highlighted the important role of N-1 in reducing renal CaOx crystals by regulating arginine metabolism in the gut microbiota. Probiotics containing L. plantarum N-1 may be potential therapies for preventing renal CaOx stones.

[Lab-scale SNAD Process in Wastewater Treatment Plant].

Outside the municipal waste water treatment plant(WWTP) which located in Mentougou District, Beijing, the effluent of the anoxic/oxic(A/O) phosphorus removal process served as the substrate to operate a completely autotrophic nitrogen removal over nitrite(CANON) filter reactor.. After the reactor was successfully activated, glucose was added to the influent as the organic carbon source. The simultaneous partial nitrification, anaerobic ammonium oxidation (ANAMMOX), and denitrification (SNAD) process was started to study the effect of SNAD filter on sewage treatment. The results showed that from 119 d to 128 d, the ammonia removal rate of the CANON process was more than 95%, and the maximum total nitrogen concentration in the effluent was 13.0 mg·L-1. Total nitrogen concentration surpassed the 1A level of the Integrated Discharge Standard of Water Pollutants applied in Beijing City. The SNAD process was started by adding glucose to the influent at 129 d. The total nitrogen removal rate of this process was about 85% at 133-187 d, and the total nitrogen concentration in the effluent was 5.5-7.3 mg·L-1. The filter plugged up at 195 d, and backwash was utilized at 196 d. During the subsequent 30 d, the total nitrogen removal rate of the reactor was greater than 85%, and the total nitrogen concentration in the effluent remained at 6.2-7.2 mg·L-1. Compared with the CANON process, the SNAD process improved the total nitrogen removal rate and reduced the total nitrogen concentration of the effluent by 6 mg·L-1. The ammonia and total nitrogen concentrations in effluent satisfied the 1A level of the Integrated Discharge Standard of Water Pollutants.