Perturbed gut microbiome and fecal and serum metabolomes are associated with chronic kidney disease severity

Integrated microbiome and metabolome analysis reveals that zishen qingre lishi huayu recipe regulates gut microbiota and butyrate metabolism to ameliorate polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a metabolic disorder disease strongly associated with gut microbiota (GM). Zishen Qingre Lishi Huayu recipe (ZQLHR), a traditional Chinese medicinal compound, has patented and shown therapeutic effects in treating PCOS in clinical trials without clear pharmacological mechanisms. This study aimed to disclose the potential therapeutic mechanism of ZQLHR on PCOS.

METHODS

We firstly confirmed the therapeutic effects of ZQLHR treatment in PCOS patients. 16 S rRNA sequencing, untargeted metabolomics, fecal microbiota transplantation (FMT), high performance liquid chromatography (HPLC) and Person's correlation analysis were conducted to elucidate the potential therapeutic mechanism.

RESULTS

These results showed that PCOS symptoms in ZQLHR patients were significantly ameliorated. ZQLHR could increase the levels of butyrate-producing Lachnospira and Faecalibacterium and decrease the abundance of Escherichia-Shigella. Untargeted metabolomics showed that ZQLHR significantly improved host metabolic function, particularly butyrate metabolism and citrate cycle (TCA cycle) metabolism. The combined Faecalibacterium and butyrate metabolism datasets were correlated. Stool samples from ZQLHR patients could ameliorate ovarian architecture, significantly reduce testosterone (T), estradiol (E2) and luteinizing hormone (LH) levels and increased follicle-stimulating hormone (FSH) levels and increase the content of butyric acid in PCOS mice (P < 0.01). Moreover, the correlation analysis showed that some biochemical parameters (T, E2, LH levels and FSH) and butyric acid were correlated.

CONCLUSION

We firstly depicted that ZQLHR could alleviate the series of symptom in women with PCOS by regulating gut microbiota and butyrate metabolism. This study provides a scientific basis and new ideas for the therapy of PCOS.

Phenol as a breath marker for hemodialysis of chronic kidney disease patients

We aimed to identify biomarkers in breath analysis with multicapillary column-ion mobility spectrometry (MCC-IMS) to monitor the haemodialysis for chronic kidney disease (CKD) patients fast and non-invasive. Six patients' breath was analyzed via MCC-IMS before and after dialysis and compared to blood plasma samples analyzed via ultra performance liquid chromatography-fluorescence detector for potential renal failure biomarkers. Additionally, breath from six healthy control persons was analyzed. Phenol was found as a breath marker for CKD. For three patients the phenol concentration in breath and plasma was elevated before and decreased during dialysis and reached values in the range of healthy control persons. The peak-intensity of phenol-monomer peaks ofP01-P04 was reduced from an average of 16.58 (5.42-27.28) a.U. to 7.03 (0.00-13.65) a.U., which is a reduction by 42.51 (-10.55-100.00) %. The control group has an average peak-intensity of 8.50 (5.00-12.00) a.U. This study shows that the measurement of phenol via breath analysis could be used to monitor the haemodialysis for CKD-patients and might also be usable for the calculation of haemodialysis dose in the future.The study is registered in the German Clinical Trials Register under number DRKS00029679.

Perturbed gut microbiota and serum metabolites are associated with progressive renal fibrosis

Introduction

The intricate pathogenesis of renal fibrosis necessitates identifying biomarkers at various stages to facilitate targeted therapeutic interventions, which would enhance patient survival rates and significantly improve prognosis.

Methods

We investigated the changes in gut microbiota and serum metabolites during the early, middle, and late stages of renal fibrosis in rats using 16S rDNA sequencing and UPLC-QTOF/MS-based metabolomics.

Results

We identified 5, 21, and 14 potential gut microbial markers and 19, 23, and 31 potential metabolic markers in the MOD1, MOD2, and MOD4 groups, respectively. Bifidobacterium was identified as a shared microbial marker between the MOD1 and MOD2 groups; Prevotellaceae_NK3B31_group and Bacteroides were identified as shared microbial markers between the MOD2 and MOD4 groups. The pathways of arachidonic acid metabolism and retinol metabolism were found to play a significant role in the modulation of renal fibrosis at 1, 2, and 4 weeks. Notably, the metabolic biomarkers 8,9-EET and 5(S)-HPETE within these pathways emerged as critical determinants influencing renal fibrosis.

Discussion

Our findings demonstrated that the severity of renal fibrosis is associated with dysbiosis of the gut microbiota and alterations in serum metabolites.

Multi-omics insights into the response of the gut microbiota and metabolites to albendazole deworming in captive Rhinopithecus brelichi

Background

Parasite infection and deworming treatment affect the host gut microbiota. Exploring the response mechanism of the gut microbiota in Rhinopithecus brelichi (R. brelichi) to albendazole deworming treatment is of great value for protecting this critically endangered species.

Methods and results

This study used metataxonomics and metabolomics to explore the responses of the gut microbiota and metabolites of R. brelichi to albendazole deworming treatment. The results showed that deworming significantly reduced the eggs per gram of feces (EPG). The 16S rRNA gene sequencing results showed that the richness and diversity of the gut microbiota in R. brelichi after deworming were significantly increased. Meanwhile, deworming treatment also changed the composition of the gut microbiota. At the genus level, the Christensenellaceae R7 group, UCG 002, UCG 005, uncultured rumen bacterium, and Rikenellaceae RC9 gut group were significantly enriched in the pre-deworming samples. Unclassified Muribaculaceae, Prevotella 9, and Bacteroides were significantly enriched in the post-deworming samples. Metabolomics analysis revealed that the relative abundance of 382 out of 1,865 metabolites showed significant differences between the pre- and post-deworming samples. Among them, 103 metabolites were annotated based on the HMDB and mainly classified into Prenol lipids, Carboxylic acids and derivatives, and Organooxygen compounds, etc. The KEGG enrichment analysis result indicated that these metabolites were mainly involved in energy, amino acid, lipid, and purine metabolism. Correlation analysis showed that Bacteroides and unclassified Muribaculaceae, whose relative abundances were upregulated after deworming treatment, were positively correlated with Kaempferol, 5,7-Dihydroxy-3-methoxy-4'-prenyloxyflavone, Purpurin, and Rhein, which have anti-parasitic activities. The Christensenellaceae R7 group, with a downregulated relative abundance after deworming treatment, was not only negatively correlated with the above four metabolites, but also positively correlated with Retinyl beta-glucuronide, which is a storage form of vitamin A, and positively correlated with CDP-Choline, which increases the host's susceptibility to Entamoeba histolytica and Plasmodium falciparum.

Conclusion

This study emphasizes that deworming treatment has an impact on the gut microbiota and metabolic functions of R. brelichi. By exploiting the correlations between differential microbiota and metabolites, potential probiotics or prebiotics can be explored, thereby enhancing the efficiency of deworming and reducing its side effects.

Gut microbiota-derived metabolites: Potential targets for cardiorenal syndrome

The characteristic of cardiorenal syndrome (CRS) is simultaneous damage to both the heart and kidneys. CRS has caused a heavy burden of mortality and incidence rates worldwide. The regulation of host microbiota metabolism that triggers heart and kidney damage is an emerging research field that promotes a new perspective on cardiovascular risk. We summarize current studies from bench to bedside of gut microbiota-derived metabolites to better understand CRS in the context of gut microbiota-derived metabolites. We focused on the involvement of gut microbiota-derived metabolites in the pathophysiology of CRS, including lipid and cholesterol metabolism disorders, coagulation abnormalities and platelet aggregation, oxidative stress, endothelial dysfunction, inflammation, mitochondrial damage and energy metabolism disorders, vascular calcification and renal fibrosis, as well as emerging therapeutic approaches targeting CRS metabolism in gut microbiota-derived metabolites which provides an innovative treatment approach for CRS to improve patient prognosis and overall quality of life.

Discussion on the treatment of diabetic kidney disease based on the "gut-fat-kidney" axis

Diabetic kidney disease is the main cause of end-stage renal disease, and its prevention and treatment are still a major clinical problem. The human intestine has a complex flora of hundreds of millions of microorganisms, and intestinal microorganisms, and their derivatives are closely related to renal inflammatory response, immune response, and material metabolism. Brown adipose tissue is the main part of adaptive thermogenesis. Recent studies have shown that activating brown fat by regulating intestinal flora has good curative effects in diabetic kidney disease-related diseases. As an emerging medical concept, the "gut-fat-kidney" axis has received increasing attention in diabetic kidney disease and related diseases. However, the specific mechanism involved needs further study. A new theoretical basis for the prevention and treatment of diabetic kidney disease is presented in this article, based on the "gut-fat-kidney" axis.

Bidirectional Association of Gut Microbiota-Derived Trimethylamine N-Oxide and its Precursors with Estimated Glomerular Filtration Rate: A Cross-Lagged Cohort Study

BACKGROUND

It is unclear whether trimethylamine N-oxide (TMAO) and its precursors are bidirectionally associated with kidney dysfunction.

OBJECTIVES

This study aims to investigate whether increased TMAO and its precursors are linked to decreased estimated glomerular filtration rate (eGFR) and whether reduced eGFR is associated with elevated TMAO and its precursors.

METHODS

Our study consists of participants with creatinine, TMAO, and its precursors (choline, carnitine, and betaine) repeatedly measured from the Fuxin rural cohort. We utilized cross-lagged panel models to assess the potential bidirectional associations of TMAO and its precursors with eGFR. Age (≥60 and <60 y) and sex-specified associations and interaction effects were examined using multi-group cross-lagged panel models. The Bonferroni method was applied for multiple comparisons.

RESULTS

Of 1746 participants [mean age 59.4 ± 9.3 y, 584 (33%) male], TMAO was inversely related to eGFR after 2 years [cross-lagged coefficient, 95% confidence interval: -0.030, -0.058, -0.002, P = 0.035], and eGFR was negatively associated with carnitine after 2 years (-0.138, -0.198, -0.078, P < 0.001). Subgroup analysis showed significant associations between baseline TMAO and eGFR after 2 years in individuals aged 60 and older (-0.061, -0.107, -0.014, P = 0.011) and between baseline eGFR and carnitine after 2 years in individuals aged 60 and older (-0.093, -0.164, -0.022, P = 0.010), in those under 60 (-0.153, -0.226, -0.079, P < 0.001), and in females (-0.154, -0.229, -0.079, P < 0.001). Additionally, baseline eGFR is nominally associated with choline after 2 years in those aged under 60 (0.092, 0.017, 0.167, P = 0.017) and in males (0.114, 0.015, 0.213, P = 0.025).

CONCLUSIONS

Deceased eGFR is related to elevated serum carnitine concentrations and may be linked to choline. Conversely, elevated TMAO may be linked to reduced kidney function. This provides novel evidence that managing healthy kidney function helps keep TMAO and its precursors at optimal levels, whereas maintaining low TMAO concentrations reduces risk of kidney disease.

Almond snacking modulates gut microbiome and metabolome in association with improved cardiometabolic and inflammatory markers

Western-style dietary patterns have been linked with obesity and associated metabolic disorders and gut dysbiosis, whereas prudent dietary and snacking choices mitigate these predispositions. Using a multi-omics approach, we investigated how almond snacking counters gut imbalances linked to adiposity and an average American Diet (AAD). Fifteen adults with overweight or obesity underwent a randomized, crossover-controlled feeding trial comparing a 4-week AAD with a similar isocaloric diet supplemented with 42.5 g/day of almonds (ALD). Almond snacking increases functional gut microbes, including Faecalibacterium prausnitzii, while suppressing opportunistic pathogens, thereby favorably modulating gut microecological niches through symbiotic and microbe-metabolite interactions. Moreover, ALD elevates health-beneficial monosaccharides and fosters bacterial consumption of amino acids, owing to enhanced microbial homeostasis. Additionally, ALD enhances metabolic homeostasis through a ketosis-like effect, reduces inflammation, and improves satiety-regulating hormones. The findings suggest that prudent dietary choices, such as almond snacking, promote gut microbial homeostasis while modulating immune metabolic state.

Dietary index for gut microbiota, a novel protective factor for the prevalence of chronic kidney diseases in the adults: insight from NHANES 2007-2018

Introduction

This study explore the association between the dietary index for gut microbiota (DI-GM) and the prevalence of chronic kidney disease (CKD).

Method

A cross-sectional study of participants aged ≥20 years using the data drawn from NHANES (2007-2018). DI-GM is comprised 14 dietary components (10 beneficial and 4 unfavorable). CKD diagnosis based on urine albumin-to-creatinine ratio (uACR) and estimated glomerular filtration rate (eGFR). Logistic regression models were employed to evaluate the relationship between DI-GM and CKD while controlling for various covariates. Additionally, a spline smooth analysis was performed. Subgroup and interaction analyses were conducted to investigate whether any factors modified this relationship.

Results

A total of 28,843 participants were eligible for the study, of whom 5,461 were diagnosed with CKD, while 23,382 were not. Patients with CKD exhibited significantly lower DI-GM scores compared to healthy individuals. A negative association between DI-GM and the prevalence of CKD was observed across all models, with the relationship being more pronounced in individuals with DI-GM scores greater than 5 compared to those with scores ≤3. Beneficial components, such as dietary fiber, whole grains, and coffee, were identified as protective factors. Moreover, sex make an effect on this relationship, with stronger effects noted in women.

Conclusion

Higher DI-GM scores correlate with reduced CKD prevalence, and the effect appears to be more pronounced in women than in men. These findings suggest that enhancing gut health through diet may serve as a viable strategy for the prevention and management of CKD, with particular attention to sex-based differences in prevention.

Dietary phytosterol supplementation mitigates renal fibrosis via activating mitophagy and modulating the gut microbiota

Chronic kidney disease (CKD) poses a significant global health challenge, primarily driven by renal fibrosis, with limited treatment options. Addressing this condition necessitates either targeted medical treatments or dietary interventions. Phytosterols (PS) are cholesterol-like bioactive compounds in various plant-based foods with antioxidant and anti-inflammatory effects. A CKD mouse model was established using folic acid (FA) and treated with dietary supplements of two PS, stigmasterol (Stig) and β-sitosterol (β-Sito). The effects and mechanisms of PS were investigated through biochemical indices, pathology, transcriptomics, and 16S rDNA sequencing. The results indicated that high-dose PS are more effective than low-dose PS and Losartan potassium (LP) in reducing renal fibrosis, restoring function, and modulating oxidative stress and inflammation, with no significant differences between high-dose Stig and β-Sito treatments. Gene Ontology (GO) enrichment analysis revealed that PS were significantly enriched in pathways related to the mitochondrial outer membrane, ubiquitin-protein ligase binding, and other cellular components and molecular processes. PS reduced the expression of TGF-β/Smad and cGAS/Sting1/TBK1 and activated PINK1/Parkin pathway proteins, thereby mitigating renal fibrosis in mice. CKD is often associated with imbalanced gut microbiota and compromised intestinal barriers. Our observations indicated that PS restored the intestinal barrier, altered the composition of the gut microbiota, and improved renal function in CKD mice. The present findings indicate that both Stig and β-Sito activate mitophagy via the PINK1/Parkin pathway and modulate the gut microbiota, thereby alleviating renal fibrosis. The findings provide solid and significant implications for developing effective application of PS supplementation in the management of CKD, presenting novel concepts and approaches for research and clinical treatment.

Personalized Nutrition in Chronic Kidney Disease

A personalized approach to nutrition in patients with chronic kidney disease (CKD) represents a promising paradigm shift in disease management, moving beyond traditional one-size-fits-all dietary recommendations. Patients with CKD often have other comorbidities and face unique nutritional challenges, including protein-energy wasting (PEW), sarcopenia, and impaired renal excretion of nutrients, which complicate dietary planning. Current guidelines focus primarily on nutrient restrictions-such as limiting protein, sodium, potassium, and phosphorus. However, these generalized recommendations often result in suboptimal adherence and outcomes. Personalized nutrition, which adapts dietary recommendations to individual characteristics, such as genotype, phenotype, and socio-cultural preferences, has gained traction across various chronic diseases. However, its application in nephrology remains underexplored, and despite promising results from studies such as Food4Me, questions remain about the real-world impact of such strategies. The aims of this review are (1) to summarize the evidence on the current state of nutritional recommendations in CKD, (2) to discuss the emerging role of multi-omics approaches in informing personalized nutrition advice in CKD, and (3) to provide an opinion on nutritional challenges faced by patients with CKD and the importance of collaboration with the renal dietician. We conclude that despite barriers, such as the cost and data integration, personalized nutrition holds the potential to improve CKD outcomes, enhance quality of life, and empower patients through tailored dietary strategies for better disease management.

Faecalibacterium prausnitzii Suppresses Mitophagy to Alleviate Muscle Atrophy in Chronic Renal Failure With Protein-Energy Wasting

Protein-energy wasting (PEW) facilitates major adverse clinical outcomes in chronic renal failure (CRF), with current therapies not suitable for all patients. Faecalibacterium prausnitzii (F. prausnitzii) can alleviate chronic kidney disease, with unclear effects and mechanisms on CRF with PEW. The CRF rat model was constructed by adenine administration, and PEW was induced by a 4% casein diet. The serum creatinine (SCR), urinary protein (UPR), and blood urea nitrogen (BUN) levels were measured by enzyme-linked immunosorbent assay. Pathology of the gastrocnemius muscle was estimated using hematoxylin and eosin staining. The expression of mitophagy-related markers was detected to assess the mitophagy level. Dexamethasone-induced L6 myotubes established myotube atrophy models. The levels of mitophagy-related markers, muscle RING-finger protein-1 (MuRF1), and atrophy gene 1 (Atrogin1) were detected by quantitative reverse transcription-polymerase chain reaction and western blotting. F. prausnitzii suppressed the SCR, UPR, and BUN expression in serum and gastrocnemius muscle atrophy, which were promoted by CRF with PEW. Dexamethasone-induced expression of MuRF1 and Atrogin1 in L6 myotubes was decreased by F. prausnitzii. Additionally, F. prausnitzii repressed mitophagy in the gastrocnemius muscle and L6 myotubes. In conclusion, F. prausnitzii suppressed renal failure progression and muscle atrophy by inhibiting mitophagy in CRF with PEW.

CKD patients comorbid with hypertension are associated with imbalanced gut microbiome

Intestinal flora has been linked to chronic kidney disease (CKD) and hypertension, respectively. This study aimed to investigate the microbial community among 54 individuals without CKD, 46 hypertensive CKD patients (CKD_HTN), and 48 non-hypertensive CKD patients. Variations in microbial diversity were detected in CKD. The Prevotella-dominated type progressively increased from CKD to CKD_HTN. Based on the variation patterns, we identified six distinct clusters. Klebsiella, Turicibacter, and Enterobacter were enriched in CKD, whereas Escherichia and Mogibacterium were elevated, and Blautia and Clostridium were reduced in CKD_HTN. Enhanced phenylalanine metabolism and siderophore group nonribosomal peptides biosynthesis from non-CKD to CKD were observed, particularly in CKD with hypertension. The connections between genera and KEGG pathways suggest an impact of microbial dysbiosis on metabolism. Our findings demonstrate that imbalances in gut microorganisms and functions are associated with increased susceptibility to hypertension in CKD patients and could be targeted for improving kidney function in CKD.

The relationship between probiotics and prebiotics, kidney dysfunction and mortality - Results from a longitudinal cohort study and Mendelian randomization

INTRODUCTION

The benefits of probiotics/prebiotics consumption on chronic kidney disease (CKD) and mortality remains controversial.

OBJECTIVES

This study investigates the association of probiotics/prebiotics consumption with chronic kidney disease (CKD) and mortality.

METHODS

Clinical data were retrieved from the National Health and Nutrition Examination Survey (NHANES) 2005-2016 database. Weighted multivariable logistic and liner regression models, cox proportional hazards models and stratified analysis were used to analyse the relationships between consumption of probiotics/prebiotics, renal parameters, CKD and mortality. We also conducted a two-sample Mendelian randomization (MR) analysis of single nucleotide polymorphisms (SNPs) related to different genera of gut microbiota to assess their causal relationships with CKD and mortality.

RESULTS

15,291 subjects were analysed (897 with consumption of probiotics/prebiotics and 14,394 without). The use of probiotics/prebiotics showed an inverse correlation with urinary albumin-to-creatinine ratio (UACR) (P < 0.05). Probiotics/prebiotics use was associated with lower risk of CKD in subjects with hypertension, hyperlipidaemia and diabetes mellitus. The consumption of probiotics/prebiotics was associated with a significantly lower risk of all-cause mortality in different regression models (P < 0.001, for all), but the lower risk of cardiovascular mortality did not reach statistical significance (P > 0.05, for all)]. MR analysis showed negative associations between the genetically predicted genus Flavonifractor and risk of CKD and diabetic kidney disease (DKD).

CONCLUSION

After multivariable regression, and cox proportional hazards analysis, we found that the use of probiotics/prebiotics was associated with improved kidney and mortality outcomes in the general population from NHANES database. The two-sample MR analysis provided further genetic evidence that a distinct genus of gut microbiota was associated with reduced risk of CKD, DKD and mortality.

Machine learning-based identification and validation of amino acid metabolism related genes as novel biomarkers in chronic kidney disease

Objectives

Chronic kidney disease (CKD) is a progressive illness with a high rate of morbidity and mortality with no proven therapy. Alterations of amino acid(AA) metabolism are associated with the incidence and progression of CKD. To characterize the potential value of AA metabolism related genes in the diagnosis and progression of CKD.

Methods

We filtered the key genes associated with AA metabolism based on the least absolute shrinkage and selection operator (LASSO) and SVM algorithm. Then, we constructed logistic regression models and evaluated the accuracy and specificity by nomogram analysis and DCA. Also, we mapped the ROC curves.Meanwhile, in order to determine the underlying mechanism and relevant biological features of CKD, we conducted differential analysis between high and low risk subgroups in CKD. Moreover,we employed ssGSEA algorithm to evaluate the infiltration abundance of immune cells and calculated the correlation among the immune cells with the key genes. Finally,we validated the expression and clinical relevance of amino acid metabolism key genes via cultured cells and clinical data. A total of six key genes related to amino acid metabolism were identified, including ALDH18A1, CENPF, CSAD, CTH, CYP27B1, HBB.

Results

All six genes exhibited promising diagnostic capabilities (AUC:0.7 to 0.9). Immune cells such as Activated CD4+ T cells, Regulatory T cells, Immature B cells and MDSC,etc.infiltrated differentially in the high and low risk groups of CKD. There were correlations between immune cells abundance and the expression of key genes. All key genes correlated significantly with markers of kidney injury, such as eGFR and serum creatinine. The expression of ALDH18A1, CENPF were increased while CSAD, CTH and CYP27B1 were decreased in HK-2 cells cultured with indole sulfate.

Conclusions

Our study identified key genes involved in amino acid metabolism associated with immune cells infiltration and renal function in CKD, which may be potential biomarkers for the diagnosis and prognosis of CKD.

Association between extracellular DNA levels, markers of inflammation and left ventricular mass index in children with chronic kidney disease

Chronic kidney disease (CKD) is associated with chronic low-grade inflammation, but the primary factors triggering this inflammation remain unclear. Extracellular or cell-free DNA (exDNA) originates from virtually all tissues, being released during cell death, and stimulates the innate immune system. Our study was designed as an observational, cross-sectional cohort study of children with CKD (both before and after kidney transplantation) and controls to analyze associations between exDNA, markers of inflammation, and cardiovascular health. Extracellular DNA (total, nuclear, and mitochondrial) was analyzed in plasma using fluorometry and real-time PCR. We found that children with CKD after kidney transplantation had higher concentrations of total and nuclear extracellular DNA (total exDNA and nc_exDNA) in plasma compared to controls. In univariate analysis, levels of interleukin-6 (IL-6), antimicrobial peptide cathelicidin (LL-37), soluble vascular cell adhesion molecule-1 (VCAM-1) and left ventricular mass index (LVMI) were positively correlated with total exDNA and nc_exDNA concentrations. Multivariate analysis revealed LVMI as the only independent variable associated with high levels of both total exDNA and nc_exDNA. We believe that our results contribute new knowledge to the pathogenesis of CKD and its complications and may help identify new treatment targets.

Nephropathy II Decoction Attenuates Renal Fibrosis via Regulating TLR4 and Gut Microbiota Along the Gut-Kidney Axis

Nephropathy II Decoction (NED) is a widely used Chinese medicinal formulation for managing chronic kidney disease (CKD). Despite its extensive application, the precise mechanisms underlying its therapeutic effects remain poorly understood. This study aims to elucidate the role of NED in attenuating renal fibrosis and to explore its impact on the gut-kidney axis. The principal constituents of NED were analyzed using ultra-performance LC-tandem mass spectrometry (UPLC-MS/MS). A bilateral renal ischemia-reperfusion injury (bIRI) model was employed to induce fibrosis. RT-qPCR was utilized to assess the expression of mRNA related to the toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) and nuclear factor-κB (NF-κB) signaling pathway. Western blotting analysis was performed to identify changes in renal fibrosis markers, TLR4/MyD88/NF-κB pathway proteins, and the colon proteins ZO-1 and Occludin-1. Serum levels of uremic toxins were quantified using enzyme-linked immunosorbent assay (ELISA), and 16S ribosomal RNA (rRNA) gene sequencing was conducted to explore changes in the gut microbiome of the mice. Our study demonstrated that mice in the NED group exhibited reduced serum creatinine, blood urea nitrogen, and urinary protein levels, alongside improvements in kidney damage and a decrease in renal fibrosis markers. In the bIRI group, TLR4/MyD88/NF-κB protein and mRNA levels, as well as intestinal tight junction proteins and enterogenic uremic toxins, were significantly reduced. NED treatment reversed these changes and modified the gut microbiota. Furthermore, fecal microbial transplantation (FMT) alleviated kidney damage and fibrosis in bIRI mice. In summary, NED ameliorates kidney injury and fibrosis by modulating the gut microbiota and may further attenuate fibrosis through the inhibition of TLR4 expression, thereby influencing the gut-kidney axis.

Probiotic interventions in peritoneal dialysis: A review of underlying mechanisms and therapeutic potentials

Peritoneal dialysis (PD) is a commonly used modality for kidney replacement therapy for patients with end-stage kidney disease (ESKD). PD offers many benefits, including home-based care, greater flexibility, and preservation of residual kidney function compared to in-center hemodialysis. Nonetheless, patients undergoing PD often face significant challenges, including systemic inflammation, PD-related peritonitis, metabolic disorders, and cardiovascular issues that can negatively affect their quality of life and treatment outcomes. Recent studies have demonstrated the crucial role of the gut microbiome in overall health and treatment results, supporting the hypothesis that probiotics may bring potential benefits to the general population of ESKD patients. However, specific data on probiotic use in PD patients are limited. This opinion review aims to summarize the current knowledge on the relationship between PD and the gut microbiome and offers a novel perspective by specifically exploring how probiotic interventions could improve the outcomes of PD treatment. The review also outlines some clinical data supporting the effectiveness of probiotics in patients undergoing PD and considers the difficulties and restrictions in their application. Based on the current knowledge gaps, this study seeks to explore future research directions and their implications for clinical practice.

Alterations in the gut microbiome and metabolism profiles reveal the possible molecular mechanism of renal injury induced by hyperuricemia in a mouse model of renal insufficiency

Objectives: To investigate the role of the intestinal flora and metabolites in the development of hyperuricemic renal injury in chronic kidney disease (CKD).Methods: Unilaterally nephrectomized mice were fed with adenine and potassium oxonate for 9 weeks. HE staining combined with plasma biochemical indicators was used to evaluate renal pathological and functional changes. We conducted 16S rRNA sequencing and untargeted metabolomics on feces and plasma samples to reveale changes in intestinal microbiota and metabolites.Result: Our analysis revealed significant differences in 15 bacterial genera, with 7 being upregulated and 8 being downregulated. Furthermore, metabolomic analysis revealed changes in the distribution of amino acid and biotin metabolites in basic metabolic pathways in both feces and serum. Specifically, differentially abundant metabolites in feces were associated primarily with histidine metabolism; the biosynthesis of phenylalanine, tyrosine, and tryptophan; and tyrosine metabolism. In plasma, the differentially abundant metabolites were involved in multiple metabolic pathways, including aminoacyl-tRNA biosynthesis; glycine, serine, and threonine amino acid metabolism; valine, leucine, and isoleucine biosynthesis; tyrosine biosynthesis and metabolism; biotin metabolism; and taurine and hypotaurine metabolism. Furthermore, correlation analysis revealed that Akkermansia, UCG-005, Lachnospiraceae_NK4A136_group, Lactococcus, and Butymonas were associated with various differentially abundant metabolites as well as renal function, oxidative stress, and mitophagy. The changes in the intestinal flora observed in hyperuricemia may lead to imbalances in amino acid and biotin metabolism in both the intestine and host, ultimately affecting oxidative stress and mitophagy in mice and accelerating the progression of CKD.Conclusion: Our findings provide insights into a potential pathogenic mechanism by which hyperuricemia exacerbates renal injury in mice with renal insufficiency. Understanding these pathways may offer new therapeutic strategies for managing hyperuricemic renal injury in CKD patients.

Gut microbiota in the association between obesity and kidney function decline: a metagenomics-based study in a rat model

OBJECTIVES

Obesity can induce dysbiosis in the gut microbiota and is considered a separate risk factor for kidney function decline. Nonetheless, the precise function of intestinal microorganisms in facilitating the connection between obesity and kidney function decline remains uncertain. Hence, the objective of this study was to investigate the alterations in the gut microbiota composition that take place during obesity and their correlations with renal function utilizing a rat model.

METHODS

For 20 weeks, 25 Sprague-Dawley rats were fed either a high-fat diet (HFD) or a normal-fat normal diet (ND). Physiological indices, peripheral plasma, kidney tissue, and colon contents were collected for comparison between groups. Metagenomic analysis of intestinal flora was performed.

RESULTS

The HFD group demonstrated significantly increased levels of creatinine and urea nitrogen in the peripheral blood. Additionally, the HFD rats exhibited a significantly larger glomerular diameter compared to the ND group, accompanied by the presence of glomerulosclerosis, tubular vacuolar transformation, and other pathological changes in certain glomeruli. Metagenomics analysis revealed a notable rise in the prevalence of the Firmicutes phylum within the HFD group, primarily comprising the Rumenococcus genus. Functional analysis indicated that the gut microbiota in the HFD group primarily correlated with infectious diseases, signal transduction, and signaling molecules and interactions.

CONCLUSIONS

This study provides evidence that the consumption of a HFD induces modifications in the composition and functionality of the gut microbiome in rats, which may serve as a potential mechanism underlying the relationship between obesity and the progression of kidney function decline.

The gut microbiome, chronic kidney disease, and sarcopenia

Sarcopenia is a prevalent condition in patients with chronic kidney disease (CKD), intricately linked to adverse prognoses, heightened cardiovascular risks, and increased mortality rates. Extensive studies have found a close and complex association between gut microbiota, kidney and muscle. On one front, patients with CKD manifest disturbances in gut microbiota and alterations in serum metabolites. These abnormal microbiota composition and metabolites in turn participate in the development of CKD. On another front, altered gut microbiota and its metabolites may lead to significant changes in metabolic homeostasis and inflammation, ultimately contributing to the onset of sarcopenia. The disturbance of gut microbial homeostasis, coupled with the accumulation of toxic metabolites, exerts deleterious effects on skeletal muscles in CKD patients with sarcopenia. This review meticulously describes the alterations observed in gut microbiota and its serum metabolites in CKD and sarcopenia patients, providing a comprehensive overview of pertinent studies. By delving into the intricate interplay of gut microbiota and serum metabolites in CKD-associated sarcopenia, we aim to unveil novel treatment strategies for ameliorating their symptoms and prognosis.

Alterations in purine and pyrimidine metabolism associated with latent tuberculosis infection: insights from gut microbiome and metabolomics analyses

Individuals with latent tuberculosis infection (LTBI) account for almost 30% of the population worldwide and have the potential to develop active tuberculosis (ATB). Despite this, the current understanding of the pathogenesis of LTBI is limited. The gut microbiome can be altered in tuberculosis patients, and an understanding of the changes associated with the progression from good health to LTBI to ATB can provide novel perspectives for understanding the pathogenesis of LTBI by identifying microbial and molecular biomarkers associated therewith. In this study, fecal samples from healthy controls (HC), individuals with LTBI and ATB patients were collected for gut microbiome and metabolomics analyses. Compared to HC and LTBI subjects, participants with ATB showed a significant decrease in gut bacterial α-diversity. Additionally, there were significant differences in gut microbial communities and metabolism among the HC, LTBI, and ATB groups. PICRUSt2 analysis revealed that microbiota metabolic pathways involving the degradation of purine and pyrimidine metabolites were upregulated in LTBI and ATB individuals relative to HCs. Metabolomic profiling similarly revealed that purine and pyrimidine metabolite levels were decreased in LTBI and ATB samples relative to those from HCs. Further correlation analyses revealed that the levels of purine and pyrimidine metabolites were negatively correlated with those of gut microbial genera represented by Ruminococcus_gnavus_group (R. gnavus), and the levels of R. gnavus were also positively correlated with adenosine nucleotide degradation II, which is a purine degradation pathway. Moreover, a combined signature including hypoxanthine and xanthine was found to effectively distinguish between LTBI and HC samples (area under the curve [AUC] of training set = 0.796; AUC of testing set = 0.924). Therefore, through gut microbiome and metabolomic analyses, these findings provide valuable clues regarding how alterations in gut purine and pyrimidine metabolism are linked to the pathogenesis of LTBI.IMPORTANCEThis study provides valuable insight into alterations in the gut microbiome and metabolomic profiles in a cohort of adults with LTBI and ATB. Perturbed gut purine and pyrimidine metabolism in LTBI was associated with the compositional alterations of gut microbiota, which may be an impetus for developing novel diagnostic strategies and interventions targeting LTBI.

Trimethylamine Induced Chronic Kidney Injury by Activating the ZBP1-NLRP3 Inflammasome Pathway

Trimethylamine N-oxide (TMAO), a bioactive metabolite of gut microbes, plays a pivotal role in the pathogenesis of kidney diseases by activating programmed cell death (PCD) pathways. However, whether trimethylamine (TMA) contributes to chronic kidney injury and which kind of PCD is involved in TMA-induced chronic kidney injury has not been previously evaluated. To observe the effect of TMA, male C57BL/6J mice were randomly divided into two groups: the Control group and the TMA group. The mice in the TMA group were intraperitoneally injected with 100 micromol/kg/day TMA for three months, whereas the mice in the Control group were injected with normal saline for the same period. After three months, plasma creatinine and blood urea nitrogen levels, indicators of kidney function, increased significantly in the TMA group as compared with those in the Control group. Furthermore, Masson staining assay showed that TMA treatment led to a larger area of fibrosis than the Control group. TMA treatment did not change the Bax/Bcl-2 ratio, RIP1, RIP3 and MLKL phosphorylation, or iron and malondialdehyde levels in kidney tissues, indicating that apoptosis, ferroptosis and necroptosis were not involved in TMA-induced chronic kidney injury. However, compared with the Control group, TMA treatment significantly upregulated NLRP3, Caspase-1, IL-1beta, cleaved-Caspase 8, Caspase-8, and ZBP1 protein expression in kidney tissues. These results indicated that the ZBP1-NLRP3 inflammasome pathway was involved in TMA-induced chronic kidney injury. In conclusion, our studies revealed that the ZBP1-NLRP3 inflammasome may take part in the progression of TMA induced chronic kidney injury.

Spatiotemporal delivery of multiple components of rhubarb-astragalus formula for the sysnergistic treatment of renal fibrosis

Purpose

Rhubarb (Rheum palmatum L.) and astragalus (Radix astragali) find widespread used in clinical formulations for treating chronic kidney disease (CKD). Notably, the key active components, total rhubarb anthraquinone (TRA) and total astragalus saponin (TAS), exhibit superiority over rhubarb and astragalus in terms of their clear composition, stability, quality control, small dosage, and efficacy for disease treatment. Additionally, astragalus polysaccharides (APS) significantly contribute to the treatment of renal fibrosis by modulating the gut microbiota. However, due to differences in the biopharmaceutical properties of these components, achieving synergistic effects remains challenging. This study aims to develop combined pellets (CPs) and evaluate the potential effect on unilateral ureteral obstruction (UUO)-induced renal fibrosis.

Methods

The CPs pellets were obtained by combining TRA/TAS-loaded SNEDDS pellets and APS-loaded pellets, prepared using the fluidized bed coating process. The prepared pellets underwent evaluation for morphology, bulk density, hardness, and flowing property. Moreover, the in vitro release of the payloads was evaluated with the CHP Type I method. Furthermore, the unilateral ureteral obstruction (UUO) model was utilized to investigate the potential effects of CPs pellets on renal fibrosis and their contribution to gut microbiota modulation.

Results

The ex-vivo study demonstrated that the developed CPs pellets not only improved the dissolution of TRA and TAS but also delivered TRA/TAS and APS spatiotemporally to the appropriate site along the gastrointestinal tract. In an animal model of renal fibrosis (UUO rats), oral administration of the CPs ameliorated kidney histological pathology, reduced collagen deposition, and decreased the levels of inflammatory cytokines. The CPs also restored the disturbed gut microbiota induced by UUO surgery and protected the intestinal barrier.

Conclusion

The developed CPs pellets represent a promising strategy for efficiently delivering active components in traditional Chinese medicine formulas, offering an effective approach for treating CKD.

Gut Microbiota and Neonatal Acute Kidney Injury

OBJECTIVE

 To characterize the relationship between gut microbiota and neonatal acute kidney injury biomarkers based on the gut-kidney axis.

STUDY DESIGN

 The Pubmed database was primarily searched to include relevant literature on gut microbiota and neonatal acute kidney injury biomarkers, which was subsequently organized and analyzed and a manuscript was written.

RESULTS

 Gut microbiota was associated with neonatal acute kidney injury biomarkers. These biomarkers included TIMP-2, IGFBP-7, VEGF, calbindin, GST, B2MG, ghrelin, and clusterin.

CONCLUSION

 The gut microbiota is strongly associated with neonatal acute kidney injury biomarkers, and controlling the gut microbiota may be a potential target for ameliorating neonatal acute kidney injury.

KEY POINTS

· There is a bidirectional association between gut microbiota and AKI.. · Gut microbiota is closely associated with biomarkers of nAKI.. · Manipulation of gut microbiota may improve nAKI..

Peritoneal dialysis promotes microbial-driven biosynthesis pathways of sesquiterpenes and triterpenes compounds in end-stage renal disease patients

The concept of the gut-kidney axis is gaining significant attention due to the close relationship between gut microbiota and kidney disease. Peritoneal dialysis is recognized as a crucial renal replacement therapy for end-stage renal disease (ESRD). The alterations in gut microbiota and related mechanisms after receiving this dialysis method are not fully understood. This study conducted shotgun metagenomic sequencing on fecal samples from 11 end-stage renal disease patients who did not receive dialysis (ESRD_N) and 7 patients who received peritoneal dialysis (ESRD_P). After quality control and correlation analysis of the data, our study is aimed at exploring the impact of peritoneal dialysis on the gut microbiota and health of ESRD patients. Our research findings indicate that the complexity and aggregation characteristics of gut microbiota interactions increase in ESRD_P. In addition, the gut microbiota drives the biosynthesis pathways of sesquiterpenes and triterpenes in ESRD_P patients, which may contribute to blood purification and improve circulation. Therefore, our research will lay the foundation for the prevention and treatment of ESRD.

Does the Composition of Gut Microbiota Affect Chronic Kidney Disease? Molecular Mechanisms Contributed to Decreasing Glomerular Filtration Rate

Chronic kidney disease (CKD) is a very prevalent and insidious disease, particularly with initially poorly manifested symptoms that progressively culminate in the manifestation of an advanced stage of the condition. The gradual impairment of kidney function, particularly decreased filtration capacity, results in the retention of uremic toxins and affects numerous molecular mechanisms within the body. The dysbiotic intestinal microbiome plays a crucial role in the accumulation of protein-bound uremic toxins such as p-cresol (pC), indoxyl sulfate (IS), and p-cresyl sulfate (p-CS) through the ongoing fermentation process. The described phenomenon leads to an elevated level of oxidative stress and inflammation, subsequently resulting in tissue damage and complications, particularly an increase in cardiovascular risk, representing the predominant cause of mortality in chronic kidney disease (CKD). Therefore, exploring methods to reduce uremic toxins is currently a pivotal therapeutic strategy aimed at reducing the risk of organ damage in patients with chronic kidney disease (CKD). This review aims to summarize recent discoveries on modifying the composition of the intestinal microbiota through the introduction of special probiotic and synbiotic supplements for CKD therapy. The potential to connect the gut microbiota with CKD opens the possibility for further extensive research in this area, which could lead to the incorporation of synbiotics and probiotics into the fundamental treatment and prevention of CKD.

Gut Microbiota in Patients Receiving Dialysis: A Review

The human gut microbiota constitutes a complex community of microorganisms residing within the gastrointestinal tract, encompassing a vast array of species that play crucial roles in health and disease. The disease processes involved in chronic kidney disease (CKD) and end-stage kidney disease (ESKD) are now increasingly established to result in dysregulation of gut microbiota composition and function. Gut microbiota dysbiosis has been associated with poor clinical outcomes and all-cause mortality in patients with ESKD, particularly individuals receiving dialysis. Prior studies highlighted various factors that affect gut microbiota dysbiosis in CKD and ESKD. These include, but are not limited to, uraemic toxin accumulation, chronic inflammation, immune dysfunction, medications, and dietary restrictions and nutritional status. There is a lack of studies at present that focus on the evaluation of gut microbiota dysbiosis in the context of dialysis. Knowledge on gut microbiota changes in this context is important for determining their impact on dialysis-specific and overall outcomes for this patient cohort. More importantly, evaluating gut microbiota composition can provide information into potential targets for therapeutic intervention. Identification of specific microbial signatures may result in further development of personalised treatments to improve patient outcomes and mitigate complications during dialysis. Optimising gut microbiota through various therapeutic approaches, including dietary adjustments, probiotics, prebiotics, medications, and faecal transplantation, have previously demonstrated potential in multiple medical conditions. It remains to be seen whether these therapeutic approaches are effective within the dialysis setting. Our review aims to evaluate evidence relating to alterations in the gut microbiota of patients undergoing dialysis. A growing body of evidence pointing to the complex yet significant relationship which surrounds gut microbiota and kidney health emphasises the importance of gut microbial balance to improve outcomes for individuals receiving dialysis.

Metabolic profiles in gestational diabetes mellitus can reveal novel biomarkers for prediction of adverse neonatal outcomes

Background

Gestational diabetes mellitus (GDM) significantly affects the fetal metabolic environment, elevating risks of neonatal hypoglycemia and macrosomia. Metabolomics offers promising avenues for early prediction and diagnosis of GDM and associated adverse offspring outcomes.

Methods

This study analyzed serum samples from pregnant women diagnosed with GDM at 24 to 28 weeks of gestation using untargeted metabolomics. We monitored the health outcomes of their offspring to explore the correlation between initial serum metabolite profiles and subsequent health outcomes, to uncover the predictive markers for hypoglycemia and macrosomia in these offspring.

Results

Out of 200 participants, 154 had normal newborns, 33 had offspring with hypoglycemia, and 19 had offspring with macrosomia. From 448 identified metabolites, 66 showed significant differences in cases of hypoglycemia, and 45 in macrosomia. A panel of serum metabolite biomarkers achieved Area Under the Curve (AUC) values of 0.8712 for predicting hypoglycemia and 0.9434 for macrosomia.

Conclusion

The study delineated metabolic disruptions in GDM during 24-28 weeks of gestation and pinpointed biomarkers capable of forecasting adverse neonatal outcomes. These findings could inform GDM management strategies and minimize the incidence of such outcomes.

The compositional and functional imbalance of the gut microbiota in CKD linked to disease patterns

BACKGROUND

The prevalence of chronic kidney disease (CKD) is on the rise, posing a significant public health challenge. Although gut microbiome dysbiosis has been implicated in the impairment of kidney functions, the existence of pathological subtypes-linked differences remains largely unknown. We aimed to characterize the intestinal microbiota in patients with membranous nephropathy (MN), IgA nephropathy (IgAN), minimal change disease (MCD), and ischemic renal injury (IRI) in order to investigate the intricate relationship between intestinal microbiota and CKD across different subtypes.

METHODS

We conducted a cross-sectional study involving 94 patients with various pathological patterns of CKD and 54 healthy controls (HCs). The clinical parameters were collected, and stool samples were obtained from each participant. Gut microbial features were analyzed using 16S rRNA sequencing and taxon annotation to compare the HC, CKD, MN, IgAN, MCD, and IRI groups.

RESULTS

The CKD subjects exhibited significantly reduced alpha diversity, modified community structures, and disrupted microbial composition and potential functions compared to the control group. The opportunistic pathogen Klebsiella exhibited a significant enrichment in patients with CKD, whereas Akkermansia showed higher abundance in HCs. The study further revealed the presence of heterogeneity in intestinal microbial signatures across diverse CKD pathological types, including MN, IgAN, MCD, and IRI. The depression of the family Lachnospiraceae and the genus Bilophila was prominently observed exclusively in patients with MN, while suppressed Streptococcus was detected only in individuals with MCD, and a remarkable expansion of the genus Escherichia was uniquely found in cases of IRI. The study also encompassed the development of classifiers employing gut microbial diagnostic markers to accurately discriminate between distinct subtypes of CKD.

CONCLUSIONS

The dysregulation of gut microbiome was strongly correlated with CKD, exhibiting further specificity towards distinct pathological patterns. Our study emphasizes the significance of considering disease subtypes when assessing the impact of intestinal microbiota on the development, diagnosis, and treatment of CKD.

Guild-level signature of gut microbiome for diabetic kidney disease

Current microbiome signatures for chronic diseases such as diabetic kidney disease (DKD) are mainly based on low-resolution taxa such as genus or phyla and are often inconsistent among studies. In microbial ecosystems, bacterial functions are strain specific, and taxonomically different bacteria tend to form co-abundance functional groups called guilds. Here, we identified guild-level signatures for DKD by performing in-depth metagenomic sequencing and conducting genome-centric and guild-based analysis on fecal samples from 116 DKD patients and 91 healthy subjects. Redundancy analysis on 1,543 high-quality metagenome-assembled genomes (HQMAGs) identified 54 HQMAGs that were differentially distributed among the young healthy control group, elderly healthy control group, early-stage DKD patients (EDG), and late-stage DKD patients (LDG). Co-abundance network analysis classified the 54 HQMAGs into two guilds. Compared to guild 2, guild 1 contained more short-chain fatty acid biosynthesis genes and fewer genes encoding uremic toxin indole biosynthesis, antibiotic resistance, and virulence factors. Guild indices, derived from the total abundance of guild members and their diversity, delineated DKD patients from healthy subjects and between different severities of DKD. Age-adjusted partial Spearman correlation analysis showed that the guild indices were correlated with DKD disease progression and with risk indicators of poor prognosis. We further validated that the random forest classification model established with the 54 HQMAGs was also applicable for classifying patients with end-stage renal disease and healthy subjects in an independent data set. Therefore, this genome-level, guild-based microbial analysis strategy may identify DKD patients with different severity at an earlier stage to guide clinical interventions.

IMPORTANCE

Traditionally, microbiome research has been constrained by the reliance on taxonomic classifications that may not reflect the functional dynamics or the ecological interactions within microbial communities. By transcending these limitations with a genome-centric and guild-based analysis, our study sheds light on the intricate and specific interactions between microbial strains and diabetic kidney disease (DKD). We have unveiled two distinct microbial guilds with opposite influences on host health, which may redefine our understanding of microbial contributions to disease progression. The implications of our findings extend beyond mere association, providing potential pathways for intervention and opening new avenues for patient stratification in clinical settings. This work paves the way for a paradigm shift in microbiome research in DKD and potentially other chronic kidney diseases, from a focus on taxonomy to a more nuanced view of microbial ecology and function that is more closely aligned with clinical outcomes.

Gut microbiota dysbiosis in hyperuricaemia promotes renal injury through the activation of NLRP3 inflammasome

BACKGROUND

The prevalence of hyperuricaemia (HUA), a metabolic disorder characterized by elevated levels of uric acid, is on the rise and is frequently associated with renal injury. Gut microbiota and gut-derived uremic toxins are critical mediators in the gut-kidney axis that can cause damage to kidney function. Gut dysbiosis has been implicated in various kidney diseases. However, the role and underlying mechanism of the gut microbiota in HUA-induced renal injury remain unknown.

RESULTS

A HUA rat model was first established by knocking out the uricase (UOX). HUA rats exhibited apparent renal dysfunction, renal tubular injury, fibrosis, NLRP3 inflammasome activation, and impaired intestinal barrier functions. Analysis of 16S rRNA sequencing and functional prediction data revealed an abnormal gut microbiota profile and activation of pathways associated with uremic toxin production. A metabolomic analysis showed evident accumulation of gut-derived uremic toxins in the kidneys of HUA rats. Furthermore, faecal microbiota transplantation (FMT) was performed to confirm the effects of HUA-induced gut dysbiosis on renal injury. Mice recolonized with HUA microbiota exhibited severe renal injury and impaired intestinal barrier functions following renal ischemia/reperfusion (I/R) surgery. Notably, in NLRP3-knockout (NLRP3-/-) I/R mice, the deleterious effects of the HUA microbiota on renal injury and the intestinal barrier were eliminated.

CONCLUSION

Our results demonstrate that HUA-induced gut dysbiosis contributes to the development of renal injury, possibly by promoting the production of gut-derived uremic toxins and subsequently activating the NLRP3 inflammasome. Our data suggest a potential therapeutic strategy for the treatment of renal diseases by targeting the gut microbiota and the NLRP3 inflammasome. Video Abstract.

Advancements in understanding the role of intestinal dysbacteriosis mediated mucosal immunity in IgA nephropathy

IgA nephropathy, presently recognized as the foremost primary glomerular disorder, emerges as a principal contributor to renal failure globally, with its pathogenesis yet to be fully elucidated. Extensive research has highlighted the critical role of gut microbiome in the onset and progression of IgA nephropathy, underscoring its importance in accurately delineating the disease's etiology. For example, gut microbiome dysbacteriosis can lead to the production of nephritogenic IgA1 antibodies, which form immune complexes that deposit in the kidneys, causing inflammation and damage. The gut microbiome, a source of numerous bioactive compounds, interacts with the host and plays a regulatory role in gut-immune axis modulation, earning it the moniker of the "second brain." Recent investigations have particularly emphasized a significant correlation between IgA nephropathy and gut microbiome dysbacteriosis. This article offers a detailed overview of the pathogenic mechanisms of IgA nephropathy, specifically focusing on elucidating how alterations in the gut microbiome are associated with anomalies in the intestinal mucosal system in IgA nephropathy. Additionally, it describes the possible influence of gut microbiome on recurrent IgA nephropathy following kidney transplantation. Furthermore, it compiles potential therapeutic interventions, offering both theoretical and practical foundations for the management of IgA nephropathy. Lastly, the challenges currently faced in the therapeutic approaches to IgA nephropathy are discussed.

Blood metabolites and chronic kidney disease: a Mendelian randomization study

BACKGROUND

Human blood metabolites have demonstrated close associations with chronic kidney disease (CKD) in observational studies. Nonetheless, the causal relationship between metabolites and CKD is still unclear. This study aimed to assess the associations between metabolites and CKD risk.

METHODS

We applied a two-sample Mendelian randomization (MR) analysis to evaluate relationships between 1400 blood metabolites and eight phenotypes (outcomes) (CKD, estimated glomerular filtration rate(eGFR), urine albumin to creatinine ratio, rapid progress to CKD, rapid decline of eGFR, membranous nephropathy, immunoglobulin A nephropathy, and diabetic nephropathy). The inverse variance weighted (IVW), MR-Egger, and weighted median were used to investigate the causal relationship. Sensitivity analyses were performed with Cochran's Q, MR-Egger intercept, MR-PRESSO Global test, and leave-one-out analysis. Bonferroni correction was used to test the strength of the causal relationship.

RESULTS

Through the MR analysis of 1400 metabolites and eight clinical phenotypes, a total of 48 metabolites were found to be associated with various outcomes. Among them, N-acetylleucine (OR = 0.923, 95%CI: 0.89-0.957, PIVW = 1.450 × 10-5) has a strong causal relationship with lower risk of CKD after the Bonferroni-corrected test, whereas Glycine to alanine ratio has a strong causal relationship with higher risk of CKD (OR = 1.106, 95%CI: 1.063-1.151, PIVW = 5.850 × 10-7). No horizontal pleiotropy and heterogeneity were detected.

CONCLUSION

Our study offers groundbreaking insights into the integration of metabolomics and genomics to reveal the pathogenesis of and therapeutic strategies for CKD. It underscores 48 metabolites as potential causal candidates, meriting further investigation.

Chronic exposure to tris(1,3-dichloro-2-propyl) phosphate: Effects on intestinal microbiota and serum metabolism in rats

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphate ester that can adversely affect animal or human health. The intestinal microbiota is critical to human health. High-dose exposure to TDCIPP can markedly affect the intestinal ecosystem of mice, but the effects of long-term exposure to lower concentrations of TDCIPP on the intestinal flora and body metabolism remain unclear. In this study, TDCIPP was administered to Sprague-Dawley rats by gavage at a dose of 13.3 mg/kg bw/day for 90 days. TDCIPP increased the relative weight of the kidneys (P = 0.017), but had no effect on the relative weight of the heart, liver, spleen, lungs, testes, and ovaries (P > 0.05). 16 S rRNA gene sequencing revealed that long-term TDCIPP exposure affected the diversity, relative abundance, and functions of rat gut microbes. The serum metabolomics of the rats showed that TDCIPP can disrupt the serum metabolic profiles, result in the up-regulation of 26 metabolites and down-regulation of 3 metabolites, and affect multiple metabolic pathways in rat sera. In addition, the disturbed genera and metabolites were correlated. The functions of some disturbed gut microbes were consistent with the affected metabolic pathways in the sera, and these metabolic pathways were all associated with kidney disease, suggesting that TDCIPP may cause kidney injury in rats by affecting the intestinal flora and serum metabolism.

Ferroptosis: a potential bridge linking gut microbiota and chronic kidney disease

Ferroptosis is a novel form of lipid peroxidation-driven, iron-dependent programmed cell death. Various metabolic pathways, including those involved in lipid and iron metabolism, contribute to ferroptosis regulation. The gut microbiota not only supplies nutrients and energy to the host, but also plays a crucial role in immune modulation and metabolic balance. In this review, we explore the metabolic pathways associated with ferroptosis and the impact of the gut microbiota on host metabolism. We subsequently summarize recent studies on the influence and regulation of ferroptosis by the gut microbiota and discuss potential mechanisms through which the gut microbiota affects ferroptosis. Additionally, we conduct a bibliometric analysis of the relationship between the gut microbiota and ferroptosis in the context of chronic kidney disease. This analysis can provide new insights into the current research status and future of ferroptosis and the gut microbiota.

Metabolites, Healthy Lifestyle, and Polygenic Risk Score Associated with Upper Gastrointestinal Cancer: Findings from the UK Biobank Study

Previous metabolomics studies have highlighted the predictive value of metabolites on upper gastrointestinal (UGI) cancer, while most of them ignored the potential effects of lifestyle and genetic risk on plasma metabolites. This study aimed to evaluate the role of lifestyle and genetic risk in the metabolic mechanism of UGI cancer. Differential metabolites of UGI cancer were identified using partial least-squares discriminant analysis and the Wilcoxon test. Then, we calculated the healthy lifestyle index (HLI) score and polygenic risk score (PRS) and divided them into three groups, respectively. A total of 15 metabolites were identified as UGI-cancer-related differential metabolites. The metabolite model (AUC = 0.699) exhibited superior discrimination ability compared to those of the HLI model (AUC = 0.615) and the PRS model (AUC = 0.593). Moreover, subgroup analysis revealed that the metabolite model showed higher discrimination ability for individuals with unhealthy lifestyles compared to that with healthy individuals (AUC = 0.783 vs 0.684). Furthermore, in the genetic risk subgroup analysis, individuals with a genetic predisposition to UGI cancer exhibited the best discriminative performance in the metabolite model (AUC = 0.770). These findings demonstrated the clinical significance of metabolic biomarkers in UGI cancer discrimination, especially in individuals with unhealthy lifestyles and a high genetic risk.

Uncovering specific taxonomic and functional alteration of gut microbiota in chronic kidney disease through 16S rRNA data

Introduction

Chronic kidney disease (CKD) is worldwide healthcare burden with growing incidence and death rate. Emerging evidence demonstrated the compositional and functional differences of gut microbiota in patients with CKD. As such, gut microbial features can be developed as diagnostic biomarkers and potential therapeutic target for CKD.

Methods

To eliminate the outcome bias arising from factors such as geographical distribution, sequencing platform, and data analysis techniques, we conducted a comprehensive analysis of the microbial differences between patients with CKD and healthy individuals based on multiple samples worldwide. A total of 980 samples from six references across three nations were incorporated from the PubMed, Web of Science, and GMrepo databases. The obtained 16S rRNA microbiome data were subjected to DADA2 processing, QIIME2 and PICRUSt2 analyses.

Results

The gut microbiota of patients with CKD differs significantly from that of healthy controls (HC), with a substantial decrease in the microbial diversity among the CKD group. Moreover, a significantly reduced abundance of bacteria Faecalibacterium prausnitzii (F. prausnitzii) was detected in the CKD group through linear discriminant analysis effect size (LEfSe) analysis, which may be associated with the alleviating effects against CKD. Notably, we identified CKD-depleted F. prausnitzii demonstrated a significant negative correlation with three pathways based on predictive functional analysis, suggesting its potential role in regulating systemic acidbase disturbance and pro-oxidant metabolism.

Discussion

Our findings demonstrated notable alterations of gut microbiota in CKD patients. Specific gut-beneficial microbiota, especially F. prausnitzii, may be developed as a preventive and therapeutic tool for CKD clinical management.

Exploring the Preventive and Therapeutic Mechanisms of Probiotics in Chronic Kidney Disease through the Gut-Kidney Axis

Gut dysbiosis contributes to deterioration of chronic kidney disease (CKD). Probiotics are a potential approach to modulate gut microbiota and gut-derived metabolites to alleviate CKD progression. We aim to provide a comprehensive view of CKD-related gut dysbiosis and a critical perspective on probiotic function in CKD. First, this review addresses gut microbial alterations during CKD progression and the adverse effects associated with the changes in gut-derived metabolites. Second, we conduct a thorough examination of the latest clinical trials involving probiotic intervention to unravel critical pathways via the gut-kidney axis. Finally, we propose our viewpoints on limitations, further considerations, and future research prospects of probiotic adjuvant therapy in alleviating CKD progression. Enhancing our understanding of host-microbe interactions is crucial for gaining precise insights into the mechanisms through which probiotics exert their effects and identifying factors that influence the effectiveness of probiotics in developing strategies to optimize their use and enhance clinical outcomes.

Landscapes of gut bacterial and fecal metabolic signatures and their relationship in severe preeclampsia

BACKGROUND

Preeclampsia is a pregnancy-specific disease leading to maternal and perinatal morbidity. Hypertension and inflammation are the main characteristics of preeclampsia. Many factors can lead to hypertension and inflammation, including gut microbiota which plays an important role in hypertension and inflammation in humans. However, alterations to the gut microbiome and fecal metabolome, and their relationships in severe preeclampsia are not well known. This study aims to identify biomarkers significantly associated with severe preeclampsia and provide a knowledge base for treatments regulating the gut microbiome.

METHODS

In this study, fecal samples were collected from individuals with severe preeclampsia and healthy controls for shotgun metagenomic sequencing to evaluate changes in gut microbiota composition. Quantitative polymerase chain reaction analysis was used to validate the reliability of our shotgun metagenomic sequencing results. Additionally, untargeted metabolomics analysis was performed to measure fecal metabolome concentrations.

RESULTS

We identified several Lactobacillaceae that were significantly enriched in the gut of healthy controls, including Limosilactobacillus fermentum, the key biomarker distinguishing severe preeclampsia from healthy controls. Limosilactobacillus fermentum was significantly associated with shifts in KEGG Orthology (KO) genes and KEGG pathways of the gut microbiome in severe preeclampsia, such as flagellar assembly. Untargeted fecal metabolome analysis found that severe preeclampsia had higher concentrations of Phenylpropanoate and Agmatine. Increased concentrations of Phenylpropanoate and Agmatine were associated with the abundance of Limosilactobacillus fermentum. Furthermore, all metabolites with higher abundances in healthy controls were enriched in the arginine and proline metabolism pathway.

CONCLUSION

Our research indicates that changes in metabolites, possibly due to the gut microbe Limosilactobacillus fermentum, can contribute to the development of severe preeclampsia. This study provides insights into the interaction between gut microbiome and fecal metabolites and offers a basis for improving severe preeclampsia by modulating the gut microbiome.

Integrating Genome Sequencing and Untargeted Metabolomics in Monozygotic Twins with a Rare Complex Neurological Disorder

Multi-omics approaches, which integrate genomics, transcriptomics, proteomics, and metabolomics, have emerged as powerful tools in the diagnosis of rare diseases. We used untargeted metabolomics and whole-genome sequencing (WGS) to gain a more comprehensive understanding of a rare disease with a complex presentation affecting female twins from a consanguineous family. The sisters presented with polymicrogyria, a Dandy-Walker malformation, respiratory distress, and multiorgan dysfunctions. Through WGS, we identified two rare homozygous variants in both subjects, a pathogenic variant in ADGRG1(p.Arg565Trp) and a novel variant in CNTNAP1(p.Glu910Val). These genes have been previously associated with autosomal recessive polymicrogyria and hypomyelinating neuropathy with/without contractures, respectively. The twins exhibited symptoms that overlapped with both of these conditions. The results of the untargeted metabolomics analysis revealed significant metabolic perturbations relating to neurodevelopmental abnormalities, kidney dysfunction, and microbiome. The significant metabolites belong to essential pathways such as lipids and amino acid metabolism. The identification of variants in two genes, combined with the support of metabolic perturbation, demonstrates the rarity and complexity of this phenotype and provides valuable insights into its underlying mechanisms.

The intestinal microbiome of children with initial and recurrent nephrolithiasis: A pilot study and exploratory analysis

INTRODUCTION

Kidney stone disease in children is rising disproportionate to the general population, representing a disease population with a distinct biological mechanism as compared to adults. Factors influencing recurrent kidney stone disease in children are poorly characterized and the associations of the intestinal microbiome within sub-populations of kidney stone formers, however, are not well described. We evaluated a pilot cohort of children with nephrolithiasis comparing patients based on recurrent kidney stone episodes and abnormal 24-h urinary parameters, with dual aims to compare the microbiome signal in children with initial and recurrent nephrolithiasis and to explore additional associations in microbiome composition and diversity within this population.

METHODS

Children aged 6-18 with a history of nephrolithiasis, without an active ureteral calculus or antibiotic exposure within 30 days of study entry were eligible to participate. All participants had a 24-h urine study within 6 months of study entry and provided a fecal sample. Microbiome samples were analyzed using 16S ribosomal DNA sequencing techniques for alpha and beta diversity comparing initial and recurrent stone formers as well as microbiome multivariate association (MaAsLin2) to determine differentially abundant taxa. Shotgun sequencing reads were aligned to custom oxidase degradation and butyrate production gene databases (5 databases total). Comparisons for MaAsLin2 and shotgun metagenomics, normalized to sequencing depth, were based on stone recurrence, sex, hypercalcuria (≤4 mg/kg/day), hyperoxaluria (≥45 mg/1.73 m2), and hypocitraturia (<310 mg/1.73 m2 [females] or < 365 mg/1.73 m2 [males]).

RESULTS

A total of 16 enrolled children provided samples sufficient for analyses, including 9 girls and 7 boys, of whom 5 had experienced recurrent kidney stone events. Three participants had hypercalcuria, 2 had hyperoxaluria, and 4 had hypocitraturia. Comparisons of Formyl-CoA transferase between index and recurrent urinary stone disease revealed a trend towards higher mean abundance of the gene in initial stone formers (0.166% vs 0.0343%, p = 0.2847) (Summary Figure), while trends toward lower biodiversity were also noted in the recurrent stone cohort on both Faith (p = 0.06) and Shannon (p = 0.05) indices. Exploratory analyses found Eubacterium siraeum to be significantly greater in relative abundance in children with documented hypercalciuria (p = 0.001).

DISCUSSION

Our pilot study demonstrates possible signals in both microbial diversity and oxalate gene expression, both of which are lower in recurrent pediatric kidney stone patients. These findings warrant further investigation as a potential diagnostic marker for future kidney stone events.

Advancing lifelong precision medicine for cardiovascular diseases through gut microbiota modulation

The gut microbiome is known as the tenth system of the human body that plays a vital role in the intersection between health and disease. The considerable inter-individual variability in gut microbiota poses both challenges and great prospects in promoting precision medicine in cardiovascular diseases (CVDs). In this review, based on the development, evolution, and influencing factors of gut microbiota in a full life circle, we summarized the recent advances on the characteristic alteration in gut microbiota in CVDs throughout different life stages, and depicted their pathological links in mechanism, as well as the highlight achievements of targeting gut microbiota in CVDs prevention, diagnosis and treatment. Personalized strategies could be tailored according to gut microbiota characteristics in different life stages, including gut microbiota-blood metabolites combined prediction and diagnosis, dietary interventions, lifestyle improvements, probiotic or prebiotic supplements. However, to fulfill the promise of a lifelong cardiovascular health, more mechanism studies should progress from correlation to causality and decipher novel mechanisms linking specific microbes and CVDs. It is also promising to use the burgeoning artificial intelligence and machine learning to target gut microbiota for developing diagnosis system and screening for new therapeutic interventions.

Gut-immune axis and cardiovascular risk in chronic kidney disease

Patients with chronic kidney disease (CKD) suffer from marked cardiovascular morbidity and mortality, so lowering the cardiovascular risk is paramount to improve quality of life and survival in CKD. Manifold mechanisms are hold accountable for the development of cardiovascular disease (CVD), and recently inflammation arose as novel risk factor significantly contributing to progression of CVD. While the gut microbiome was identified as key regulator of immunity and inflammation in several disease, CKD-related microbiome-immune interaction gains increasing importance. Here, we summarize the latest knowledge on microbiome dysbiosis in CKD, subsequent changes in bacterial and host metabolism and how this drives inflammation and CVD in CKD. Moreover, we outline potential therapeutic targets along the gut-immune-cardiovascular axis that could aid the combat of CVD development and high mortality in CKD.

Gut-Kidney-Heart: A Novel Trilogy

The microbiota represents a key factor in determining health and disease. Its role in inflammation and immunological disorders is well known, but it is also involved in several complex conditions, ranging from neurological to psychiatric, from gastrointestinal to cardiovascular diseases. It has recently been hypothesized that the gut microbiota may act as an intermediary in the close interaction between kidneys and the cardiovascular system, leading to the conceptualization of the "gut-kidney-heart" axis. In this narrative review, we will discuss the impact of the gut microbiota on each system while also reviewing the available data regarding the axis itself. We will also describe the role of gut metabolites in this complex interplay, as well as potential therapeutical perspectives.

Washed microbiota transplantation improves renal function in patients with renal dysfunction: a retrospective cohort study

BACKGROUND

Changes in the gut microbiota composition is a hallmark of chronic kidney disease (CKD), and interventions targeting the gut microbiota present a potent approach for CKD treatment. This study aimed to evaluate the efficacy and safety of washed microbiota transplantation (WMT), a modified faecal microbiota transplantation method, on the renal activity of patients with renal dysfunction.

METHODS

A comparative analysis of gut microbiota profiles was conducted in patients with renal dysfunction and healthy controls. Furthermore, the efficacy of WMT on renal parameters in patients with renal dysfunction was evaluated, and the changes in gut microbiota and urinary metabolites after WMT treatment were analysed.

RESULTS

Principal coordinate analysis revealed a significant difference in microbial community structure between patients with renal dysfunction and healthy controls (P = 0.01). Patients with renal dysfunction who underwent WMT exhibited significant improvement in serum creatinine, estimated glomerular filtration rate, and blood urea nitrogen (all P < 0.05) compared with those who did not undergo WMT. The incidence of adverse events associated with WMT treatment was low (2.91%). After WMT, the Shannon index of gut microbiota and the abundance of several probiotic bacteria significantly increased in patients with renal dysfunction, aligning their gut microbiome profiles more closely with those of healthy donors (all P < 0.05). Additionally, the urine of patients after WMT demonstrated relatively higher levels of three toxic metabolites, namely hippuric acid, cinnamoylglycine, and indole (all P < 0.05).

CONCLUSIONS

WMT is a safe and effective method for improving renal function in patients with renal dysfunction by modulating the gut microbiota and promoting toxic metabolite excretion.

[Clinical significance of uremic toxin indoxyl sulfate and inflammation in the development of vascular calcification and cardiovascular complications in stage C3-C5D chronic kidney disease]

AIM

To clarify the role of the uremic toxin indoxyl sulfate (IS) and inflammation in the development of vascular calcification and cardiovascular complications in chronic kidney disease (CKD).

MATERIALS AND METHODS

One hundred fifteen patients aged 25 to 68 years with CKD stage C3-C5D were examined. Serum concentrations of IS, interleukin 6 (IL-6), tumor necrosis factor (TNF-α), troponin I, parathyroid hormone were determined by enzyme immunoassay using kits from BluGene biotech (Shanghai, China), Cloud-Clone Corp. (USA), ELISA Kit (Biomedica, Austria).

RESULTS

An increase in the serum concentration of IS, IL-6, TNF-α was revealed, which was significantly associated with a deterioration in renal function and changes in the morphological and functional parameters of the heart and aorta.

CONCLUSION

High concentrations of IS, IL-6, TNF-α, which are closely associated with an increase in renal failure and cardiovascular complications, indicate their significant role in vascular calcification, which underlies the damage to the cardiovascular system in CKD.

Environmental insults and compensative responses: when microbiome meets cancer

Tumor microenvironment has recently been ascribed a new hallmark-the polymorphic microbiome. Accumulating evidence regarding the tissue specific territories of tumor-microbiome have opened new and interesting avenues. A pertinent question is regarding the functional consequence of the interface between host-microbiome and cancer. Given microbial communities have predominantly been explored through an ecological perspective, it is important that the foundational aspects of ecological stress and the fight to 'survive and thrive' are accounted for tumor-micro(b)environment as well. Building on existing evidence and classical microbial ecology, here we attempt to characterize the ecological stresses and the compensative responses of the microorganisms inside the tumor microenvironment. What insults would microbes experience inside the cancer jungle? How would they respond to these insults? How the interplay of stress and microbial quest for survival would influence the fate of tumor? This work asks these questions and tries to describe this underdiscussed ecological interface of the tumor and its microbiota. It is hoped that a larger scientific thought on the importance of microbial competition sensing vis-à-vis tumor-microenvironment would be stimulated.

Age- and Gender-Specific Diagnostic Value of the Albumin-to-Creatinine Ratio for the Early Screening of Chronic Kidney Disease Among Middle-Aged and Elderly Males in Southeast China

Objective

To evaluate the potential diagnostic value of the albumin-to-creatinine ratio (ACR) in screening for early kidney injury in a physically examined population from Southeast China.

Methods

A total of 13,250 candidates were selected. Urinary ACR values <30, 30-300, and >300 mg/g were utilized as positive cut-off points to denote normal proteinuria, microalbuminuria, and macroalbuminuria, respectively.

Results

Age, systolic blood pressure, diastolic blood pressure, body mass index, waistline, fasting blood glucose, glycated hemoglobin, triglycerides, and high-density lipoprotein cholesterol were significantly different among the three groups. eGFR was negatively correlated with the levels of sCr, BUN, and UA in the microalbuminuria and macroalbuminuria groups. Furthermore, there was a significant difference in CKD stage between the normal and abnormal urine ACR groups. Meanwhile, for the 20-40 years patients, the eGFR, sCr and BUN showed no significant difference between microalbuminuria group compared with the normal proteinuria group; in contrast, for the 41-60 years and >61 years patients, eGFR, sCr, BUN and UA were all markedly increase in microalbuminuria and macroalbuminuria group in comparison with the normal proteinuria group. Finally, for the 41-60 males, only eGFR significantly decreased in microalbuminuria group compared with the normal proteinuria group, while for the 41-60 females, only UA showed no significant difference between microalbuminuria group and normal proteinuria group. On the other hand, for the >61 males, eGFR, sCr and BUN all significantly changed between microalbuminuria group and normal proteinuria group, while for the >61 females, eGFR, sCr and BUN all showed no significant difference between microalbuminuria group and normal proteinuria group, as well as microalbuminuria group and macroalbuminuria group.

Conclusion

We proposed using the urinary ACR for the screening of physically examined patients, especially among the elderly males. This approach would assist in the early diagnosis and treatment of renal damage.

Association between salivary microbiota and renal function in renal transplant patients during the perioperative period

Introduction

Renal transplantation is an effective treatment for the end stage renal disease (ESRD). However, how salivary microbiota changes during perioperative period of renal transplant recipients (RTRs) has not been elucidated.

Methods

Five healthy controls and 11 RTRs who had good recovery were enrolled. Saliva samples were collected before surgery and at 1, 3, 7, and 14 days after surgery. 16S rRNA gene sequencing was performed.

Results

There was no significant difference in the composition of salivary microbiota between ESRD patients and healthy controls. The salivary microbiota of RTRs showed higher operational taxonomic units (OTUs) amount and greater alpha and beta diversity than those of ESRD patients and healthy controls, but gradually stabilized over time. At the phylum level, the relative abundance of Actinobacteria, Tenericutes and Spirochaetes was about ten times different from ESRD patients or healthy controls for RTRs overall in time. The relative abundance of Bacteroidetes, Fusobacteria, Patescibacteria, Leptotrichiaceae and Streptococcaceae was correlated with serum creatinine (Scr) after renal transplantation.

Discussion

In short, salivary microbiota community altered in the perioperative period of renal transplantation and certain species of salivary microbiota had the potential to be a biomarker of postoperative recovery.