The crosstalk of gut microbiota and chronic kidney disease: role of inflammation, proteinuria, hypertension, and diabetes mellitus. Int Urol Nephrol. 2018;50:1453-1466. [PMID: 29728993 DOI: 10.1007/s11255-018-1873-2]

Genetically predicted inflammatory proteins mediate the association between gut microbiota and renal cell carcinoma

BACKGROUND

Studies have indicated a potential relationship between gut microbiota and renal cell carcinoma. However, the causal relationship between various types of gut microbiota and renal cell carcinoma, as well as the role of inflammatory protein as mediators, remains unclear.

METHODS

This study aimed to identify the relationship between gut microbiota, inflammatory protein, and renal cell cancer through a large-scale genome-wide association study (GWAS) utilizing pooled data. We employed Mendelian randomization (MR) to investigate the causal relationship among these variables. Inverse variance weighting (IVW) was utilized as the primary statistical method. Furthermore, we examined the mediating role of inflammatory protein in the pathway through which gut microbiota influences the development of renal cell cancer.

RESULTS

The analysis revealed 12 positive causal relationships and 15 negative causal relationships between the genetic liability of gut microbiota and renal cell cancer. Furthermore, there were three positive causal relationships and one negative causal relationship between inflammatory proteins and renal cell cancer. There were two axes of relationships in which gut microbiota promote the development of renal cell cancer. through inflammatory proteins acting as mediators.

CONCLUSIONS

Gut microbiota and inflammatory protein were causally related to renal cell cancer, and inflammatory protein were intermediary factors in the pathway between gut microbiota and renal cell cancer.

Dietary index for gut microbiota and its protective role against kidney stones: evidence of diabetes as a mediator from NHANES cross-sectional data

Background

The dietary index for gut microbiota (DI-GM) reflects dietary patterns that support gut microbial health and may influence kidney stone (KS) risk. The role of DI-GM and its mediation by diabetes in KS pathogenesis remains unclear.

Objective

To investigate the association between DI-GM and KS prevalence, assess the mediation effect of diabetes, and explore subgroup-specific effects and underlying mechanisms.

Methods

A cross-sectional analysis of NHANES (2007-2018) data was conducted using a stratified, multistage probability sampling design. A total of 19,841 participants were included in the final analysis. Data entry and statistical analysis were performed using Empower version 4.2 (X&Y Solutions, Inc., Boston, MA, United States) and R version 3.4.3 (R Foundation). Multivariable logistic regression was employed to assess the association between DI-GM and KS prevalence, with statistical significance set at p < 0.05. Mediation analysis evaluated diabetes's contribution to this relationship, and subgroup analyses were conducted based on sex, race/ethnicity, and alcohol consumption.

Results

Higher DI-GM scores were associated with lower KS prevalence (adjusted OR: 0.78, 95% CI: 0.65-0.92 per SD increase). Diabetes mediated 9.27% of this relationship. Subgroup analyses revealed stronger protective effects among females, non-Hispanic Black individuals, and heavy drinkers. Mechanistically, DI-GM may reduce KS risk through gut microbial modulation of oxalate metabolism, urinary citrate excretion, and systemic inflammation.

Conclusion and recommendations

Higher DI-GM scores are associated with reduced KS prevalence, partially mediated by diabetes. These findings highlight the role of dietary interventions targeting gut microbiota in KS prevention and call for longitudinal studies to confirm these results and develop tailored dietary strategies.

Low-Grade Chronic Inflammation: a Shared Mechanism for Chronic Diseases

Inflammation is an important physiological response of the organism to restore homeostasis upon pathogenic or damaging stimuli. However, the persistence of the harmful trigger or a deficient resolution of the process can evolve into a state of low-grade, chronic inflammation. This condition is strongly associated with the development of several increasingly prevalent and serious chronic conditions, such as obesity, cancer, and cardiovascular diseases, elevating overall morbidity and mortality worldwide. The current pandemic of chronic diseases underscores the need to address chronic inflammation, its pathogenic mechanisms, and potential preventive measures to limit its current widespread impact. The present review discusses the current knowledge and research gaps regarding the association between low-grade chronic inflammation and chronic diseases, focusing on obesity, cardiovascular diseases, digestive diseases, and cancer. We examine the state of the art in selected aspects of the topic and propose future directions and approaches for the field.

Gut-brain axis and neuroplasticity in health and disease: a systematic review

The gut microbiota emerged as a potential modulator of brain connectivity in health and disease. This systematic review details current evidence on the gut-brain axis and its influence on brain connectivity. The initial set of studies included 532 papers, updated to January 2024. Studies were selected based on employed techniques. We excluded reviews, studies without connectivity focus, studies on non-human subjects. Forty-nine papers were selected. Employed techniques in healthy subjects included 15 functional magnetic resonance imaging studies (fMRI), 5 diffusion tensor imaging, (DTI) 1 electroencephalography (EEG), 6 structural magnetic resonance imaging, 2 magnetoencephalography, 1 spectroscopy, 2 arterial spin labeling (ASL); in patients 17 fMRI, 6 DTI, 2 EEG, 9 structural MRI, 1 transcranial magnetic stimulation, 1 spectroscopy, 2 R2*MRI. In healthy subjects, the gut microbiota was associated with connectivity of areas implied in cognition, memory, attention and emotions. Among the tested areas, amygdala and temporal cortex showed functional and structural differences based on bacteria abundance, as well as frontal and somatosensory cortices, especially in patients with inflammatory bowel syndrome. Several studies confirmed the connection between microbiota and brain functions in healthy subjects and patients affected by gastrointestinal to renal and psychiatric diseases.

Exploration of the pathogenesis of nephrotic syndrome and traditional Chinese medicine intervention based on gut microbiota

Nephrotic syndrome (NS) represents a prevalent syndrome among various chronic kidney disease pathologies and is known for its higher severity and worse prognosis compared with chronic glomerulonephritis. Understanding its pathogenesis and identifying more effective treatment modalities have long been a concern of kidney specialists. With the introduction of the gut-kidney axis concept and the progress in omics technologies, alterations in the gut microbiota have been observed in primary and secondary NS. This link has been extensively researched in conditions such as diabetic nephropathy and immunoglobulin A (IgA) nephropathy. Thus, dysbiosis of the gut microbiota is seen as a crucial contributing factor in NS; however, there is a lack of comprehensive reviews that elucidate the changes in the gut microbiota across different NS conditions and that describe its mechanistic role in the disease. Moreover, serving as an innate regulator of the gut microbiota, traditional Chinese medicine (TCM) has the potential to exert a profound impact on the expression of inflammation-promoting agents, decreasing the levels of endotoxins and uremic toxins. In addition, it strengthens the stability of the intestinal barrier while controlling the metabolic function of the body through its efficient modulation of the gut microbiota. This intricate process yields far-reaching consequences for NS.

Effects of probiotics and fibers on markers of nephropathy, inflammation, intestinal barrier dysfunction and endothelial dysfunction in individuals with type 1 diabetes and albuminuria. The ProFOS Study

AIMS

To estimate whether a mix of pre- and probiotics would strengthen the gut barrier and protect the kidneys in individuals with type 1 diabetes and albuminuria.

METHODS

Randomized, placebo-controlled, crossover study. Forty-one participants received synbiotic (pre- and probiotics) mix or placebo for 12 weeks with 6 weeks washout. Primary endpoint was change from baseline to end-of-period in UACR. Secondary endpoints were changes in endothelial glycocalyx thickness, inflammatory and intestinal barrier dysfunction markers, glomerular filtration rate (GFR) and ambulatory systolic blood pressure.

RESULTS

Thirty-five participants completed the study. Mean age was 58 (SD 10) years, 73 % (n = 30) were male, median UACR was 134 (IQR 63-293) mg/g, estimated GFR was 75 (30) ml/min/1.73m2. There was no significant difference in UACR with a mean relative change (CI 95 %) from baseline to end-of-treatment of -3.0 (-18.4; 15.5) % in the synbiotic group and -12.0 (-29.6; 9.6) % in the placebo group with no significant difference between treatment periods (9.37 (-25.2; 44.0) percentage points; p = 0.60). No significant beneficial difference in the secondary end points was demonstrated.

CONCLUSION

Twelve weeks treatment with synbiotic mix had no effect on UACR or on any of the secondary endpoints in subjects with type 1 diabetes and albuminuria.

Gut microbiota and renal fibrosis

Renal fibrosis represents a critical pathological condition in the progression of renal dysfunction, characterized by aberrant accumulation of extracellular matrix (ECM) and structural alterations in renal tissue. Recent research has highlighted the potential significance of gut microbiota and demonstrated their influence on host health and disease mechanisms through the production of bioactive metabolites. This review examines the role of alterations in gut microbial composition and their metabolites in the pathophysiological processes underlying renal fibrosis. It delineates current therapeutic interventions aimed at modulating gut microbiota composition, encompassing dietary modifications, pharmacological approaches, and probiotic supplementation, while evaluating their efficacy in mitigating renal fibrosis. Through a comprehensive analysis of current research findings, this review enhances our understanding of the bidirectional interaction between gut microbiota and renal fibrosis, establishing a theoretical foundation for future research directions and potential clinical applications in this domain.

Exploring the potential link between gut microbiota and chronic kidney disease in causality: A 2-sample Mendelian randomization study

Increasing evidence indicates a significant correlation between gut microbiota (GM) and susceptibility to chronic kidney disease (CKD). However, causal relationship presence remains uncertain. Mendelian randomization (MR) was applied to evaluate potential causal relation from GM to CKD. Genomic association analysis aggregates publicly online databases, utilizing Genome-Wide Association Study (GWAS) database focused on GM and CKD. For examination of potential causal connection from GM to CKD, a 2-way, 2-sample Mendelian randomization (MR) method was applied. Sensitivity analyses were utilized to scrutinize for heterogeneity, horizontal pleiotropy, MR outcomes resilience. Result from inverse variance weighting (IVW) method revealed that 10 microbiotas such as Porphyromonadaceae (OR = 1.351, 95% CI: 1.114-1.638, P = .002), Dorea (OR = 1.236, 95% CI: 1.040-1.468, P = .016), Ruminococcus torques group (OR = 1.290, 95% CI: 1.035-1.608, P = .024) are potential CKD risk factors. Five microbiotas, including the Prevotellaceae (OR = 0.814, 95% CI: 0.719-0.922, P = .001) are potential CKD protective factors. Sensitivity analyses reveal no horizontal pleiotropy or heterogeneity. Additionally, reverse MR results unveiled potential relation between CKD and disorders in 3 microbiotas, including Senegalimassilia. According to the investigation, MR method was employed to delve into reciprocal causal connection from GM to CKD. Our findings identified 15 types of GM causally linked to CKD, as well as CKD demonstrating causal associations with 3 types of GM. Further exploration of these associated GM types is hopeful to raise novel insights, for CKD preventing and early monitoring.

Early and late gut microbiota signatures of stroke in high salt-fed stroke-prone spontaneously hypertensive rats

The high salt-fed stroke-prone spontaneously hypertensive rat (SHRSP) is a suitable tool to study the mechanisms underlying stroke pathogenesis. Salt intake modifies the gut microbiota (GM) in rats and humans and alterations of the GM have previously been associated with increased stroke occurrence. We aimed to characterize the GM profile in SHRSPs fed a high-salt stroke-permissive diet (Japanese diet, JD), compared to the closely related stroke-resistant control (SHRSR), to identify possible changes associated with stroke occurrence. SHRSPs and SHRSRs were fed a regular diet or JD for 4 weeks (short-term, ST) or a maximum of 10 weeks (long-term, LT). Stroke occurred in SHRSPs on JD-LT, preceded by proteinuria and diarrhoea. The GM of JD-fed SHRSPs underwent early and late compositional changes compared to SHRSRs. An overrepresentation of Streptococcaceae and an underrepresentation of Lachnospiraceae were observed in SHRSPs JD-ST, while in SHRSPs JD-LT short-chain fatty acid producers, e.g. Lachnobacterium and Faecalibacterium, decreased and pathobionts such as Coriobacteriaceae and Desulfovibrio increased. Occludin gene expression behaved differently in SHRSPs and SHRSRs. Calprotectin levels were unchanged. In conclusion, the altered GM in JD-fed SHRSPs may be detrimental to gut homeostasis and contribute to stroke occurrence.

Broadening horizons: intestinal microbiota as a novel biomarker and potential treatment for hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy (HDP) are severe complications of pregnancy with high morbidity and are a major cause of increased maternal and infant morbidity and mortality. Currently, there is a lack of effective early diagnostic indicators and safe and effective preventive strategies for HDP in clinical practice, except for monitoring maternal blood pressure levels, the degree of proteinuria, organ involvement and fetal conditions. The intestinal microbiota consists of the gut flora and intestinal environment, which is the largest microecosystem of the human body and participates in material and energy metabolism, gene expression regulation, immunity regulation, and other functions. During pregnancy, due to changes in hormone levels and altered immune function, the intestinal microecological balance is affected, triggering HDP. A dysregulated intestinal microenvironment influences the composition and distribution of the gut flora and changes the intestinal barrier, driving beneficial or harmful bacterial metabolites and inflammatory responses to participate in the development of HDP and promote its malignant development. When the gut flora is dysbiotic and affects blood pressure, supplementation with probiotics and dietary fiber can be used to intervene. In this review, the interaction between the intestinal microbiota and HDP was investigated to explore the feasibility of the gut flora as a novel biomarker of HDP and to provide a new strategy and basis for the prevention and treatment of clinical HDP.

Toll-like receptor 4 mutation mitigates gut microbiota-mediated hypertensive kidney injury

Hypertension-associated dysbiosis is linked to several clinical complications, including inflammation and possible kidney dysfunction. Inflammation and TLR4 activation during hypertension result from gut dysbiosis-related impairment of intestinal integrity. However, the contribution of TLR4 in kidney dysfunction during hypertension-induced gut dysbiosis is unclear. We designed this study to address this knowledge gap by utilizing TLR4 normal (TLR4N) and TLR4 mutant (TLR4M) mice. These mice were infused with high doses of Angiotensin-II for four weeks to induce hypertension. Results suggest that Ang-II significantly increased renal arterial resistive index (RI), decreased renal vascularity, and renal function (GFR) in TLR4N mice compared to TLR4M. 16 S rRNA sequencing analysis of gut microbiome revealed that Ang-II-induced hypertension resulted in alteration of Firmicutes: Bacteroidetes ratio in the gut of both TLR4N and TLR4M mice; however, it was not comparably rather differentially. Additionally, Ang-II-hypertension decreased the expression of tight junction proteins and increased gut permeability, which were more prominent in TLR4N mice than in TLR4M mice. Concomitant with gut hyperpermeability, an increased bacterial component translocation to the kidney was observed in TLR4N mice treated with Ang-II compared to TLR4N plus saline. Interestingly, microbiota translocation was mitigated in Ang-II-hypertensive TLR4M mice. Furthermore, Ang-II altered the expression of inflammatory (IL-1β, IL-6) and anti-inflammatory IL-10) markers, and extracellular matrix proteins, including MMP-2, -9, -14, and TIMP-2 in the kidney of TLR4N mice, which were blunted in TLR4M mice. Our data demonstrate that ablation of TLR4 attenuates hypertension-induced gut dysbiosis resulting in preventing gut hyperpermeability, bacterial translocation, mitigation of renal inflammation and alleviation of kidney dysfunction.

A Symbiotic Meal Containing Extruded Sorghum and Probiotic (Bifidobacterium longum) Ameliorated Intestinal Health Markers in Individuals with Chronic Kidney Disease: A Secondary Analysis of a Subsample from a Previous Randomized and Controlled Clinical Trial

BACKGROUND

Chronic kidney disease increases uremic toxins concentrations, which have been associated with intestinal dysbiosis. Sorghum bicolor L. Moench has dietary fiber and bioactive compounds, while Bifidobacterium longum can promote beneficial health effects.

METHODS

It is a controlled, randomized, and single-blind clinical trial. Thirty-nine subjects were randomly separated into two groups: symbiotic group (SG), which received 100 mL of unfermented probiotic milk with Bifidobacterium longum strain and 40 g of extruded sorghum flakes; and the control group (CG), which received 100 mL of pasteurized milk and 40 g of extruded corn flakes for seven weeks.

RESULTS

The uremic toxins decreased, and gastrointestinal symptoms improved intragroup in the SG group. The acetic, propionic, and butyric acid production increased intragroup in the SG group. Regarding α-diversity, the Chao1 index was enhanced in the SG intragroup. The KEGG analysis revealed that symbiotic meal increased the intragroup energy and amino sugar metabolism, in addition to enabling essential amino acid production and metabolism, sucrose degradation, and the biosynthesis of ribonucleotide metabolic pathways.

CONCLUSIONS

The consumption of symbiotic meal reduced BMI, improved short-chain fatty acid (SCFA) synthesis and gastrointestinal symptoms, increased diversity according to the Chao1 index, and reduced uremic toxins in chronic kidney disease patients.

Modulating the Gut Microbiota and Metabolites with Traditional Chinese Medicines: An Emerging Therapy for Type 2 Diabetes Mellitus and Its Complications

Currently, an estimated 537 million individuals are affected by type 2 diabetes mellitus (T2DM), the occurrence of which is invariably associated with complications. Glucose-lowering therapy remains the main treatment for alleviating T2DM. However, conventional antidiabetic agents are fraught with numerous adverse effects, notably elevations in blood pressure and lipid levels. Recently, the use of traditional Chinese medicines (TCMs) and their constituents has emerged as a preferred management strategy aimed at curtailing the progression of diabetes and its associated complications with fewer adverse effects. Increasing evidence indicates that gut microbiome disturbances are involved in the development of T2DM and its complications. This regulation depends on various metabolites produced by gut microbes and their interactions with host organs. TCMs' interventions have demonstrated the ability to modulate the intestinal bacterial microbiota, thereby restoring host homeostasis and ameliorating metabolic disorders. This review delves into the alterations in the gut microbiota and metabolites in T2DM patients and how TCMs treatment regulates the gut microbiota, facilitating the management of T2DM and its complications. Additionally, we also discuss prospective avenues for research on natural products to advance diabetes therapy.

Exploring environmental exposomes and the gut-brain nexus: Unveiling the impact of pesticide exposure

This review delves into the escalating concern of environmental pollutants and their profound impact on human health in the context of the modern surge in global diseases. The utilisation of chemicals in food production, which results in residues in food, has emerged as a major concern nowadays. By exploring the intricate relationship between environmental pollutants and gut microbiota, the study reveals a dynamic bidirectional interplay, as modifying microbiota profile influences metabolic pathways and subsequent brain functions. This review will first provide an overview of potential exposomes and their effect to gut health. This paper is then emphasis the connection of gut brain function by analysing microbiome markers with neurotoxicity responses. We then take pesticide as example of exposome to elucidate their influence to biomarkers biosynthesis pathways and subsequent brain functions. The interconnection between neuroendocrine and neuromodulators elements and the gut-brain axis emerges as a pivotal factor in regulating mental health and brain development. Thus, manipulation of gut microbiota function at the onset of stress may offer a potential avenue for the prevention and treatment for mental disorder and other neurodegenerative illness.

Identification of circRNAs expression profiles and functional networks in parotid gland of type 2 diabetes mouse

BACKGROUND

Circular RNAs (circRNAs) are a novel kind of non-coding RNAs proved to play crucial roles in the development of multiple diabetic complications. However, their expression and function in diabetes mellitus (DM)-impaired salivary glands are unknown.

RESULTS

By using microarray technology, 663 upregulated and 999 downregulated circRNAs companied with 813 upregulated and 525 downregulated mRNAs were identified in the parotid glands (PGs) of type2 DM mice under a 2-fold change and P < 0.05 cutoff criteria. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analysis of upregulated mRNAs showed enrichments in immune system process and peroxisome proliferator-activated receptor (PPAR) signaling pathway. Infiltration of inflammatory cells and increased inflammatory cytokines were observed in diabetic PGs. Seven differently expressed circRNAs validated by qRT-PCR were selected for coding-non-coding gene co-expression (CNC) and competing endogenous RNA (ceRNA) networks analysis. PPAR signaling pathway was primarily enriched through analysis of circRNA-mRNA networks. Moreover, the circRNA-miRNA-mRNA networks highlighted an enrichment in the regulation of actin cytoskeleton.

CONCLUSION

The inflammatory response is elevated in diabetic PGs. The selected seven distinct circRNAs may attribute to the injury of diabetic PG by modulating inflammatory response through PPAR signaling pathway and actin cytoskeleton in diabetic PGs.

An altered gut microbiome in pre-eclampsia: cause or consequence

Hypertensive disorders of pregnancy, including pre-eclampsia, are a leading cause of serious and debilitating complications that affect both the mother and the fetus. Despite the occurrence and the health implications of these disorders there is still relatively limited evidence on the molecular underpinnings of the pathophysiology. An area that has come to the fore with regard to its influence on health and disease is the microbiome. While there are several microbiome niches on and within the body, the distal end of the gut harbors the largest of these impacting on many different systems of the body including the central nervous system, the immune system, and the reproductive system. While the role of the microbiome in hypertensive disorders, including pre-eclampsia, has not been fully elucidated some studies have indicated that several of the symptoms of these disorders are linked to an altered gut microbiome. In this review, we examine both pre-eclampsia and microbiome literature to summarize the current knowledge on whether the microbiome drives the symptoms of pre-eclampsia or if the aberrant microbiome is a consequence of this condition. Despite the paucity of studies, obvious gut microbiome changes have been noted in women with pre-eclampsia and the individual symptoms associated with the condition. Yet further research is required to fully elucidate the role of the microbiome and the significance it plays in the development of the symptoms. Regardless of this, the literature highlights the potential for a microbiome targeted intervention such as dietary changes or prebiotic and probiotics to reduce the impact of some aspects of these disorders.

Microbiota analysis in individuals with type two diabetes mellitus and end‑stage renal disease: A pilot study

Chronic kidney disease (CKD) is a widespread health concern, which affects ~9.1% of the global population and 12-15% of individuals in upper-middle income countries. Notably, ~2% of patients with CKD progress to end-stage renal disease (ESRD), which leads to a substantial decline in the quality of life, an increased risk of mortality and significant financial burden. Patients with ESRD often still suffer from uremia and uremic syndromes, due to the accumulation of toxins between dialysis sessions and the inadequate removal of protein-bound toxins during dialysis. A number of these toxins are produced by the gut microbiota through the fermentation of dietary proteins or cholines. Furthermore, the gut microbial community serves a key role in maintaining metabolic and immune equilibrium in individuals. The present study aimed to investigate the gut microbiota patterns in individuals with type 2 diabetes mellitus (T2DM) and ESRD via quantitative PCR analysis of the 16S and 18S ribosomal RNA of selected members of the gut microbiota. Individuals affected by both T2DM and ESRD displayed distinctive features within their intestinal microbiota. Specifically, there were increased levels of Gammaproteobacteria observed in these patients, and all subjects exhibited a notably increased presence of Enterobacteriaceae compared with healthy individuals. This particular microbial community has established connections with the presence of inflammatory processes in the colon. Moreover, the elevated levels of Enterobacteriaceae may serve as an indicator of an imbalance in the intestinal microbiota, a condition known as dysbiosis. In addition, the Betaproteobacteria phylum was significantly more prevalent in the stool samples of patients with both T2DM and ESRD when compared with the control group. In conclusion, the present pilot study focused on gut microbiome alterations in T2DM and ESRD. Understanding the relationship between dysbiosis and CKD may identify new areas of research and therapeutic interventions aimed at modulating the gut microbiota to improve the health and outcomes of individuals with CKD and ESRD.

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.

Role of Synbiotics (Prebiotics and Probiotics) as Dietary Supplements in Type 2 Diabetes Mellitus Induced Health Complications

Diabetes is a metabolic disorder whose prevalence has become a worrying condition in recent decades. Chronic diabetes can result in serious health conditions such as impaired kidney function, stroke, blindness, and myocardial infarction. Despite a variety of currently available treatments, cases of diabetes and its complications are on the rise. This review article provides a comprehensive account of the ameliorative effect of prebiotics and probiotics individually or in combination i.e. synbiotics on health complications induced by Type 2 Diabetes Mellitus (T2DM). Recent advances in the field underscore encouraging outcomes suggesting the consumption of synbiotics leads to favorable changes in the gut microbiota. These changes result in the production of bioactive metabolites such as short-chain fatty acids (crucial for lowering blood sugar levels), reducing inflammation, preventing insulin resistance, and encouraging the release of glucagon-like peptide-1 in the host. Notably, novel strategies supplementing synbiotics to support gut microbiota are gaining attraction as pivotal interventions in mitigating T2DM-induced health complications. Thus, by nurturing a symbiotic relationship between prebiotics and probiotics i.e. synbiotics, these interventions hold promise in reshaping the microbial landscape of the gut thereby offering a multifaceted approach to managing T2DM and its associated morbidities. Supporting the potential of synbiotics underscores a paradigm shift toward holistic and targeted interventions in diabetes management, offering prospects for improved outcomes and enhanced quality of life for affected individuals. Nevertheless, more research needs to be done to better understand the single and multispecies pre/pro and synbiotics in the prevention and management of T2DM-induced health complications.

Changes in the Progression of Chronic Kidney Disease in Patients Undergoing Fecal Microbiota Transplantation

Chronic kidney disease (CKD) is a progressive loss of renal function in which gut dysbiosis is involved. Fecal microbiota transplantation (FMT) may be a promising alternative for restoring gut microbiota and treating CKD. This study evaluated the changes in CKD progression in patients treated with FMT. Patients with diabetes and/or hypertension with CKD clinical stages 2, 3, and 4 in this single-center, double-blind, randomized, placebo-controlled clinical trial (NCT04361097) were randomly assigned to receive either FMT or placebo capsules for 6 months. Laboratory and stool metagenomic analyses were performed. A total of 28 patients were included (15 FMT and 13 placebo). Regardless of CKD stages, patients responded similarly to FMT treatment. More patients (53.8%) from the placebo group progressed to CKD than the FMT group (13.3%). The FMT group maintained stable renal function parameters (serum creatinine and urea nitrogen) compared to the placebo group. Adverse events after FMT treatment were mild or moderate gastrointestinal symptoms. The abundance of Firmicutes and Actinobacteria decreased whereas Bacteroidetes, Proteobacteria and Roseburia spp. increased in the FMT group. CKD patients showed less disease progression after FMT administration. The administration of oral FMT in patients with CKD is a safe strategy, does not represent a risk, and has potential benefits.

Specific gut microbiome and metabolome changes in patients with continuous ambulatory peritoneal dialysis and comparison between patients with different dialysis vintages

Background

In recent years, the role of gut microbiota and derived metabolites in renal disease has attracted more attention. It has been established that the gut microbiota is a potential target for medical interventions in renal disease including chronic kidney disease (CKD), acute kidney injury (AKI) and renal calculus. Emerging evidence has related dialysis treatment to the microbial composition and function of the intestines, and there are many reports related to HD, but few studies have been related to PD. Previous studies have found that PD patients have intestinal flora disturbances, so we speculate that intestinal flora and its metabolites may be the regulatory factors in long-term therapy of PD. And as far as we know, there have been no studies characterized the gut microbiota in PD patients of different dialysis vintages.

Methods

It is a cross-sectional study based on clinical data and biological samples of 72 patients with CAPD, 13 patients with ESRD and 13 healthy volunteers. The intestinal microecological characteristics of CAPD patients were comprehensively evaluated by combining the intestinal microflora structure, enterotoxin and receptor (serum LPS and LBP), intestinal barrier function index (serum D-Lactate), intestinal uremic toxin (serum IS, PCS, TMAO), fecal SCFAs and other multi-dimensional and multi-omics studies. Furthermore, the changes of intestinal microecology in CAPD patients of different dialysis vintages (≥ 3 and < 12 months, ≥ 12 and < 24 months, ≥ 24 and < 60 months, ≥ 60 months) were further explored, and the correlations between intestinal microecology indicators and some clinical indicators were analyzed. Fecal and serum samples were collected from PD patients (PD group, n = 72), ESRD patients (ESRD group, n = 13) and healthy volunteers (Normal group, n = 13). Fecal samples were subjected to microbiome (16S rDNA) and SCFA (GC-MS) analyses. Serum samples were subjected to LPS, LBP, D-lactate, IS, PCS, and TMAO (ELISA) analyses.

Results

The diversity and richness of intestinal flora in CAPD patients were lower than those in healthy people and ESRD patients, and the microflora structure was different. Anaerobes of Blautia and facultative anaerobes and aerobic bacteria with Bacilli and Lactobacillales those in Firmicutes are the main intestinal flora in CAPD patients. The abundance of Bacteroidaceae, Bacteroides, Faecalibacterium and other dominant bacteria in the intestinal tract of CAPD patients decreased. Proteobacteria, Enterobacteriaceae and Escherichia-Shigella increased their colonization (LDA > 4). In CAPD patients of different dialysis vintages, there was no significant change in the diversity and richness of microflora, and the microflora structure of PDC group was significantly different from that of PDD, which the abnormal expansion of enterobacter group was more prominent in PDC and the abundance of Bacteroides group was relatively higher in PDD. Intestinal barrier damage, intestinal uremic toxin accumulation and short-chain fatty acid reduction were observed in CAPD patients, such as the serum level of D-Lactate, PCS and TMAO were significantly higher than that in the Normal group (P < 0.05),and the fecal levels of BA and CA were significantly lower (P < 0.05). The intestinal microecological disorder of PDC group, while that of PDD group showed a better trend. Such as the PDC group had a significantly higher serum level of LPS, D-Lactate and TMAO (P < 0.01), and significantly lower serum level of LBP (P < 0.01), and lower fecal levels of AA and BA (P > 0.05) than the PDD group.

Conclusion

The intestinal microecology and metabolic system of CAPD patients had changes compared with healthy people and ESRD non-dialysis patients, and there were differences in CAPD patients with different dialysis vintages. PD patients on dialysis for more than 60 months showed a better trend in the intestinal microecology than patients with 24∼36 months, which suggested that the intestinal microecology of PD patients had a certain ability of self-regulation and remodeling under the management of standardized system and it is necessary to strengthen the monitoring of the intestinal status and the occurrence of related complications in PD patients on dialysis of 24∼36 months of dialysis vintage. It is initially considered that the mechanism of intestinal microecology is a potential target for intervention in the diagnosis and treatment of CAPD and incorporating intestinal microecosystem monitoring into the long-term management of CAPD patients is a new strategy.

Does Indoxyl Sulfate Have a Role in Uremic Pruritus? A Laboratory and Interventional Study

BACKGROUND

Pruritus is a common complaint in patients with end-stage renal disease. Indoxyl sulfate (IS) is a tryptophan end metabolite extremely renal excreted. Activated charcoal can interfere with IS intestinal absorption.

OBJECTIVES

To evaluate the serum level of IS and the effect of activated charcoal on uremic pruritus.

MATERIALS AND METHODS

In all, 135 participants were divided into 2 main groups. In total, 45 normal and healthy individuals as a control group and 90 patients on regular hemodialysis; 45 of these patients had uremic pruritus and the other 45 were not complaining of uremic pruritus. Serum IS was measured. Activated charcoal was used by patients with uremic pruritus. The severity of pruritus and Dermatology Life Quality Index (DLQI) were assessed.

RESULTS

The serum IS was significantly elevated in uremic patients than in control subjects (P < .001) and significantly elevated in uremic patients without pruritus (P < .001). Furthermore, there were positive significant correlations between the serum IS and both severity of pruritus (P < .001) and DLQI (P < .001). After activated charcoal usage, there was a significant decrease in IS level with the improvement of pruritus and quality of life of patients.

CONCLUSIONS

IS may play a role in uremic pruritus. Activated charcoal could be considered a treatment for uremic pruritus.

Hydrangea paniculata coumarins attenuate experimental membranous nephritis by bidirectional interactions with the gut microbiota

Coumarins isolated from Hydrangea paniculata (HP) had a renal protective effect in experimental membranous nephritis (MN), but the mechanisms are not clear. Currently, we investigate whether the modulation of gut dysbiosis by HP contributes to its renal protection. Experimental MN rats were treated with HP for six weeks. Fecal 16S rDNA sequencing and metabolomics were performed. Fecal microbiota transplantation (FMT) was used for the evaluation study. The results demonstrate that deteriorated renal function and gut dysbiosis are found in MN rats, as manifested by a higher Firmicutes/Bacteroidetes ratio and reduced diversity and richness, but both changes were reversed by HP treatment. Reduced gut dysbiosis is correlated with improved colonic integrity and lower endotoxemia in HP-treated rats. HP normalized the abnormal level of fecal metabolites by increasing short-chain fatty acid production and hindering the production of uremic toxin precursors. FMT of HP-treated feces to MN animals moderately reduced endotoxemia and albuminuria. Moreover, major coumarins in HP were only biotransformed into more bioactive 7-hydroxycoumarin by gut microbiota, which strengthened the effect of HP in vivo. Depletion of the gut microbiota partially abolished its renal protective effect. In conclusion, the bidirectional interaction between HP and the gut microbiota contributes to its beneficial effect.

Jiangtang Decoction Ameliorates Diabetic Kidney Disease Through the Modulation of the Gut Microbiota

Purpose

This study aimed to elucidate the impact of Jiangtang decoction (JTD) on diabetic kidney disease (DKD) and its association with alterations in the gut microbiota.

Methods

Using a diabetic mouse model (KK-Ay mice), daily administration of JTD for eight weeks was undertaken. Weekly measurements of body weight and blood glucose were performed, while kidney function, uremic toxins, inflammation factors, and fecal microbiota composition were assessed upon sacrifice. Ultra-structural analysis of kidney tissue was conducted to observe the pathological changes.

Results

The study findings demonstrated that JTD improve metabolism, kidney function, uremic toxins and inflammation, while also exerting a modulatory effect on the gut microbiota. Specifically, the genera Rikenella, Lachnoclostridium, and unclassified_c_Bacilli exhibited significantly increased abundance following JTD treatment, accompanied by reduced abundance of norank_f_Lachnospiraceae compared to the model group. Importantly, Rikenella and unclassified_c_Bacilli demonstrated negative correlations with urine protein levels. Lachnoclostridium and norank_f_Lachnospiraceae were positively associated with creatinine (Cr), indoxyl sulfate (IS) and interleukin (IL)-6. Moreover, norank_f_Lachnospiraceae exhibited positive associations with various indicators of DKD severity, including weight, blood glucose, urea nitrogen (UN), kidney injury molecule-1 (KIM-1) levels, trimethylamine-N-oxide (TMAO), p-cresyl sulfate (pCS), nucleotide-binding oligomerization domain (Nod)-like receptor family pyrin domain-containing 3 (NLRP3) and IL-17A production.

Conclusion

These findings suggested that JTD possess the ability to modulate the abundance of Rikenella, Lachnoclostridium, unclassified_c_Bacilli and norank_f_Lachnospiraceae within the gut microbiota. This modulation, in turn, influenced metabolic processes, kidney function, uremic toxin accumulation, and inflammation, ultimately contributing to the amelioration of DKD.

A new immune disease: systemic hypertension

Systemic hypertension is the most common medical comorbidity affecting the adult population globally, with multiple associated outcomes including cerebrovascular diseases, cardiovascular diseases, vascular calcification, chronic kidney disease, metabolic syndrome and mortality. Despite advancements in the therapeutic field approximately one in every five adult patients with hypertension is classified as having treatment-resistant hypertension, indicating the need for studies to provide better understanding of the underlying pathophysiology and the need for more therapeutic targets. Recent pre-clinical studies have demonstrated the role of the innate and adaptive immune system including various cell types and cytokines in the pathophysiology of hypertension. Moreover, pre-clinical studies have indicated the potential beneficial effects of immunosuppressant medications in the control of hypertension. Nevertheless, it is unclear whether such pathophysiological mechanisms and therapeutic alternatives are applicable to human subjects, while this area of research is undoubtedly a rapidly growing field.

Gut Microbiota Interventions to Retain Residual Kidney Function

Residual kidney function for patients with chronic kidney disease (CKD) is associated with better quality of life and outcome; thus, strategies should be implemented to preserve kidney function. Among the multiple causes that promote kidney damage, gut dysbiosis due to increased uremic toxin production and endotoxemia need attention. Several strategies have been proposed to modulate the gut microbiota in these patients, and diet has gained increasing attention in recent years since it is the primary driver of gut dysbiosis. In addition, medications and faecal transplantation may be valid strategies. Modifying gut microbiota composition may mitigate chronic kidney damage and preserve residual kidney function. Although various studies have shown the influential role of diet in modulating gut microbiota composition, the effects of this modulation on residual kidney function remain limited. This review discusses the role of gut microbiota metabolism on residual kidney function and vice versa and how we could preserve the residual kidney function by modulating the gut microbiota balance.

Urinary microbiota and serum metabolite analysis in patients with diabetic kidney disease

Background

Diabetic kidney disease (DKD) is a common and potentially fatal consequence of diabetes. Chronic renal failure or end-stage renal disease may result over time. Numerous studies have demonstrated the function of the microbiota in health and disease. The use of advanced urine culture techniques revealed the presence of resident microbiota in the urinary tract, undermining the idea of urine sterility. Studies have demonstrated that the urine microbiota is related with urological illnesses; nevertheless, the fundamental mechanisms by which the urinary microbiota influences the incidence and progression of DKD remain unclear. The purpose of this research was to describe key characteristics of the patients with DKD urinary microbiota in order to facilitate the development of diagnostic and therapeutic for DKD.

Methods

We evaluated the structure and composition of the microbiota extracted from urine samples taken from DKD patients (n = 19) and matched healthy controls (n = 15) using 16S rRNA gene sequencing. Meanwhile, serum metabolite profiles were compared using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Associations between clinical characteristics, urine microbiota, and serum metabolites were also examined. Finally, the interaction between urine microbiota and serum metabolites was clarified based on differential metabolite abundance analysis.

Results

The findings indicated that the DKD had a distinct urinary microbiota from the healthy controls (HC). Taxonomic investigations indicated that the DKD microbiome had less alpha diversity than a control group. Proteobacteria and Acidobacteria phyla increased in the DKD, while Firmicutes and Bacteroidetes decreased significantly (P < 0.05). Acidobacteria was the most prevalent microbiota in the DKD, as determined by the Linear discriminant analysis Effect Size (LEfSe) plot. Changes in the urinary microbiota of DKD also had an effect on the makeup of metabolites. Short-chain fatty acids (SCFAs) and protein-bound uremic toxins (PBUTs) were shown to be specific. Then we discovered that arginine and proline metabolism was the primary mechanism involved in the regulation of diabetic kidney disease.

Conclusions

This study placed the urinary microbiota and serum metabolite of DKD patients into a functional framework and identified the most abundant microbiota in DKD (Proteobacteria and Acidobacteria). Arginine metabolites may have a major effect on DKD patients, which correlated with the progression of DKD.

The altered composition of gut microbiota and biochemical features as well as dietary patterns in a southern Chinese population with recurrent renal calcium oxalate stones

The correlation among gut microbiota, biochemical features, and dietary patterns in recurrent stone formers has been inadequately investigated in the Chinese population. Forty-two patients with calcium oxalate stones (CaOxS group), including 34 recurrent stone formers (RS group), and 40 nonstone healthy subjects (NS group) from Changshu Hospital Affiliated with Soochow University, were prospectively recruited. Food frequency questionnaires were completed by participants, fasting vein blood was extracted, 24-h urine was collected for biochemical detection, and fecal samples were gathered for 16S ribosomal RNA (rRNA) gene sequencing. BMI; serum levels of triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), magnesium, and creatinine; and urine levels of magnesium in stone formers were significantly different from those of controls, and RS patients showed significantly low serum phosphate and high urine phosphate levels. Celery, bamboo shoots, and pickled food were the favored foods of local stone formers. Patients with recurrent stones had altered microbiota composition, with Escherichia, Fusobacterium, and Epulopiscium being the predominant pathogenic genera. The gut microbiota in RS patients had stronger functions in fatty acid and amino acid degradation but weaker functions in their biosynthesis. The pathogenic genera were positively correlated with BMI; serum levels of TGs and creatinine; urine levels of calcium, phosphate, and uric acid (UA); and celery, bamboo shoots, and pickled food intake. The abundance of Escherichia and Fusobacterium and the levels of serum magnesium and creatinine were the most relevant factors associated with stone recurrence and could be validated as biomarkers of recurrence. Our research provides a novel prevention strategy for the recurrence of renal calcium oxalate stones in the Han Chinese population of southern China.

Hypertension and cellular senescence

Essential or primary hypertension is a wordwide health problem. Elevated blood pressure (BP) is closely associated not only with increased chronological aging but also with biological aging. There are various common pathways that play a role in cellular aging and BP regulation. These include but not limited to inflammation, oxidative stress, mitochondrial dysfunction, air pollution, decreased klotho activity increased renin angiotensin system activation, gut dysbiosis etc. It has already been shown that some anti-hypertensive drugs have anti-senescent actions and some senolytic drugs have BP lowering effects. In this review, we have summarized the common mechanisms underlying cellular senescence and HT and their relationships. We further reviewed the effect of various antihypertensive medications on cellular senescence and suggest further issues to be studied.

Intestinal microbiome diversity of diabetic and non-diabetic kidney disease: Current status and future perspective

A significant portion of the health burden of diabetic kidney disease (DKD) is caused by both type 1 and type 2 diabetes which leads to morbidity and mortality globally. It is one of the most common diabetic complications characterized by loss of renal function with high prevalence, often leading to acute kidney disease (AKD). Inflammation triggered by gut microbiota is commonly associated with the development of DKD. Interactions between the gut microbiota and the host are correlated in maintaining metabolic and inflammatory homeostasis. However, the fundamental processes through which the gut microbiota affects the onset and progression of DKD are mainly unknown. In this narrative review, we summarised the potential role of the gut microbiome, their pathogenicity between diabetic and non-diabetic kidney disease (NDKD), and their impact on host immunity. A well-established association has already been seen between gut microbiota, diabetes and kidney disease. The gut-kidney interrelationship is confirmed by mounting evidence linking gut dysbiosis to DKD, however, it is still unclear what is the real cause of gut dysbiosis, the development of DKD, and its progression. In addition, we also try to distinguish novel biomarkers for early detection of DKD and the possible therapies that can be used to regulate the gut microbiota and improve the host immune response. This early detection and new therapies will help clinicians for better management of the disease and help improve patient outcomes.

Association between probiotic, prebiotic, and yogurt consumption and chronic kidney disease: The NHANES 2010-2020

Background

Previous studies suggested that gut dysbacteriosis may promote the occurrence of chronic kidney disease (CKD), and probiotic, prebiotic, or yogurt supplements may alleviate CKD progression. This study aims to examine the association between probiotic, prebiotic, or yogurt supplements and the risk of CKD using the data from NHANES.

Methods

This study was designed to prospectively search data from the National Health and Nutrition Examination Survey (NHANES) (2011-2020). We examined dietary supplements and prescription medication labels to identify probiotic, or prebiotic product, and yogurt consumption during the dietary interview. The diagnosis of CKD was determined by the value of glomerular filtration rate (eGFR) and albumin creatinine ratio (ACR).

Results

The study enrolled a total of 6,522 individuals. The prevalence of CKD was lower in the probiotic, prebiotic, or yogurt consumption group [age-adjusted odds ratio (OR): 0.77, 95% CI: 0.62-0.95, P = 0.02; multivariable-adjusted OR: 0.86, 95% CI: 0.69-1.07, P = 0.05]. Furthermore, 32% reduced risk was observed in the older group aged 55 years or older, and 32% reduced risk was also observed in the female population. Probiotic, or prebiotic, or yogurt supplements was associated a 12% reduction in moderate risk of CKD and an 11% reduction in very high risk of CKD.

Conclusion

Our results suggest that probiotic, prebiotic, or yogurt supplements may contribute to the prevention of CKD and relieve its progression risk, especially in the female population and older population who were aged 55 years or older.

Microbiota and glomerulonephritis: An immunological point of view

Glomerular injury is the major cause of chronic kidney diseases (CKD) worldwide and is characterized by proteinuria. Glomerulonephritis (GN) has a wide spectrum of etiologies, the intensity of glomerular damage, histopathology, and clinical outcomes that can be associated with the landscape of the nephritogenic immune response. Beyond impaired immune responses and genetic factors, recent evidence indicates that microbiota can be contributed to the pathogenesis of GN and patients' outcomes by impacting many aspects of the innate and adaptive immune systems. It is still unknown whether dysbiosis induces GN or it is a secondary effect of the disease. Several factors such as drugs and nutritional problems can lead to dysbiosis in GN patients. It has been postulated that gut dysbiosis activates immune responses, promotes a state of systemic inflammation, and produces uremic toxins contributing to kidney tissue inflammation, apoptosis, and subsequent proteinuric nephropathy. In this review, the impact of gastrointestinal tract (GI) microbiota on the pathogenesis of the primary GN will be highlighted. The application of therapeutic interventions based on the manipulation of gut microbiota with special diets and probiotic supplementation can be effective in GN.

Gut Microbiota Associated with Gestational Health Conditions in a Sample of Mexican Women

Gestational diabetes (GD), pre-gestational diabetes (PD), and pre-eclampsia (PE) are morbidities affecting gestational health which have been associated with dysbiosis of the mother's gut microbiota. This study aimed to assess the extent of change in the gut microbiota diversity, short-chain fatty acids (SCFA) production, and fecal metabolites profile in a sample of Mexican women affected by these disorders. Fecal samples were collected from women with GD, PD, or PE in the third trimester of pregnancy, along with clinical and biochemical data. Gut microbiota was characterized by high-throughput DNA sequencing of V3-16S rRNA gene libraries; SCFA and metabolites were measured by High-Pressure Liquid Chromatography (HPLC) and (Fourier Transform Ion Cyclotron Mass Spectrometry (FT-ICR MS), respectively, in extracts prepared from feces. Although the results for fecal microbiota did not show statistically significant differences in alfa diversity for GD, PD, and PE concerning controls, there was a difference in beta diversity for GD versus CO, and a high abundance of Proteobacteria, followed by Firmicutes and Bacteroidota among gestational health conditions. DESeq2 analysis revealed bacterial genera associated with each health condition; the Spearman's correlation analyses showed selected anthropometric, biochemical, dietary, and SCFA metadata associated with specific bacterial abundances, and although the HPLC did not show relevant differences in SCFA content among the studied groups, FT-ICR MS disclosed the presence of interesting metabolites of complex phenolic, valeric, arachidic, and caprylic acid nature. The major conclusion of our work is that GD, PD, and PE are associated with fecal bacterial microbiota profiles, with distinct predictive metagenomes.

Resistant Starch as a Dietary Intervention to Limit the Progression of Diabetic Kidney Disease

Diabetes is the leading cause of kidney disease, and as the number of individuals with diabetes increases there is a concomitant increase in the prevalence of diabetic kidney disease (DKD). Diabetes contributes to the development of DKD through a number of pathways, including inflammation, oxidative stress, and the gut-kidney axis, which may be amenable to dietary therapy. Resistant starch (RS) is a dietary fibre that alters the gut microbial consortium, leading to an increase in the microbial production of short chain fatty acids. Evidence from animal and human studies indicate that short chain fatty acids are able to attenuate inflammatory and oxidative stress pathways, which may mitigate the progression of DKD. In this review, we evaluate and summarise the evidence from both preclinical models of DKD and clinical trials that have utilised RS as a dietary therapy to limit the progression of DKD.

Homeostasis in the Gut Microbiota in Chronic Kidney Disease

The gut microbiota consists of trillions of microorganisms, fulfilling important roles in metabolism, nutritional intake, physiology and maturation of the immune system, but also aiding and abetting the progression of chronic kidney disease (CKD). The human gut microbiome consists of bacterial species from five major bacterial phyla, namely Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, and Verrucomicrobia. Alterations in the members of these phyla alter the total gut microbiota, with a decline in the number of symbiotic flora and an increase in the pathogenic bacteria, causing or aggravating CKD. In addition, CKD-associated alteration of this intestinal microbiome results in metabolic changes and the accumulation of amines, indoles and phenols, among other uremic metabolites, which have a feedforward adverse effect on CKD patients, inhibiting renal functions and increasing comorbidities such as atherosclerosis and cardiovascular diseases (CVD). A classification of uremic toxins according to the degree of known toxicity based on the experimental evidence of their toxicity (number of systems affected) and overall experimental and clinical evidence was selected to identify the representative uremic toxins from small water-soluble compounds, protein-bound compounds and middle molecules and their relation to the gut microbiota was summarized. Gut-derived uremic metabolites accumulating in CKD patients further exhibit cell-damaging properties, damage the intestinal epithelial cell wall, increase gut permeability and lead to the translocation of bacteria and endotoxins from the gut into the circulatory system. Elevated levels of endotoxins lead to endotoxemia and inflammation, further accelerating CKD progression. In recent years, the role of the gut microbiome in CKD pathophysiology has emerged as an important aspect of corrective treatment; however, the mechanisms by which the gut microbiota contributes to CKD progression are still not completely understood. Therefore, this review summarizes the current state of research regarding CKD and the gut microbiota, alterations in the microbiome, uremic toxin production, and gut epithelial barrier degradation.

Alterations of gut microbial pathways and virulence factors in hemodialysis patients

Alterations in gut microbiota might contribute to uremic toxicity and immune dysregulation in patients with end-stage renal disease. Hemodialysis patients are prone to infection and higher mortality following sepsis. The virulence factors in the gut metagenome have not been well studied in hemodialysis patients, which could be employed by microorganisms to successfully thrive and flourish in their hosts. In this study, we performed shotgun metagenomics sequencing on fecal DNA collected from 16 control subjects and 24 hemodialysis patients. Our analysis shows that a number of microbial species, metabolic pathways, antibiotic resistance, and virulence factors were significantly altered in hemodialysis patients compared with controls. In particular, erythromycin resistance methylase, pyridoxamine 5-phosphate oxidase, and streptothricin-acetyl-transferase were significantly increased in hemodialysis patients. The findings in our study laid a valuable foundation to further elucidate the causative role of virulence factors in predisposing HD patients to infection and to develop treatment strategies to reduce the genetic capacities of antibiotic resistance and virulence factors in HD patients.

The role and mechanisms of gut microbiota in diabetic nephropathy, diabetic retinopathy and cardiovascular diseases

Type 2 diabetes mellitus (T2DM) and T2DM-related complications [such as retinopathy, nephropathy, and cardiovascular diseases (CVDs)] are the most prevalent metabolic diseases. Intriguingly, overwhelming findings have shown a strong association of the gut microbiome with the etiology of these diseases, including the role of aberrant gut bacterial metabolites, increased intestinal permeability, and pathogenic immune function affecting host metabolism. Thus, deciphering the specific microbiota, metabolites, and the related mechanisms to T2DM-related complications by combined analyses of metagenomics and metabolomics data can lead to an innovative strategy for the treatment of these diseases. Accordingly, this review highlights the advanced knowledge about the characteristics of the gut microbiota in T2DM-related complications and how it can be associated with the pathogenesis of these diseases. Also, recent studies providing a new perspective on microbiota-targeted therapies are included.

Comparing probiotic and drug interventions in irritable bowel syndrome: a meta-analysis of randomised controlled trials

Clinical decisions made by health professionals to recommend either drug or probiotic interventions for irritable bowel syndrome (IBS) should be supported by proper knowledge of the efficacy rates of both types of interventions. In this article, we performed a systematic review and meta-analysis to examine the efficacy of both probiotic- and drug interventions in IBS. Medline was searched between January 2015 - January 2021. Randomised controlled trials (RCT) recruiting participants > 18 years old with IBS and examining the effect of probiotics or drugs were eligible for inclusion. The data of the primary outcome, i.e. the persistence of IBS symptoms (dichotomous symptom data), were pooled to obtain a relative risk (RR), with a 95% confidence interval (CI). Secondary outcomes, abdominal pain- and bloating scores (continuous data), were pooled using a standardised mean difference with a 95% CI. The search identified 269 citations of which 32 RCTs were eligible. Our meta-analysis indicated that both probiotic and drug interventions are able to improve the persistence of IBS symptoms (RR 0.60 [0.51; 0.92] versus 0.87 [0.81; 0.92], respectively) and abdominal pain scores (standardised mean difference (SMD) -0.35 [-0.56; -0.14] versus -0.10 [-0.20; 0.00], respectively). However, determining the overall efficacy of both intervention types is inherently complex and such results should be interpreted with care, due to the large diversity of probiotic- and drug types and doses, which is also complicated by variety in IBS subtypes. Hence, as a first step, more large scale randomised double blind placebo-controlled trials focussing on a specific IBS subtype targeted with specific probiotic strains or specific pharmaceutical modalities should be executed, enabling a more proper comparison between trials.

Faecal Microbiota Transplantation and Chronic Kidney Disease

Faecal microbiota transplantation (FMT) has attracted increasing attention as an intervention in many clinical conditions, including autoimmune, enteroendocrine, gastroenterological, and neurological diseases. For years, FMT has been an effective second-line treatment for Clostridium difficile infection (CDI) with beneficial outcomes. FMT is also promising in improving bowel diseases, such as ulcerative colitis (UC). Pre-clinical and clinical studies suggest that this microbiota-based intervention may influence the development and progression of chronic kidney disease (CKD) via modifying a dysregulated gut–kidney axis. Despite the high morbidity and mortality due to CKD, there are limited options for treatment until end-stage kidney disease occurs, which results in death, dialysis, or kidney transplantation. This imposes a significant financial and health burden on the individual, their families and careers, and the health system. Recent studies have suggested that strategies to reverse gut dysbiosis using FMT are a promising therapy in CKD. This review summarises the preclinical and clinical evidence and postulates the potential therapeutic effect of FMT in the management of CKD.

The impact of prebiotic fructooligosaccharides on gut dysbiosis and inflammation in obesity and diabetes related kidney disease

Obesity is an extensive health problem worldwide that is frequently associated with diabetes. It is a risk factor for the development of several diseases including diabetic nephropathy. Recent studies have reported that gut dysbiosis aggravates the progression of obesity and diabetes by increasing the production of uremic toxins in conjunction with gut barrier dysfunction which then leads to increased passage of lipopolysaccharides (LPS) into the blood circulatory system eventually causing systemic inflammation. Therefore, the modification of gut microbiota using a prebiotic supplement may assist in the restoration of gut barrier function and reduce any disturbance of the inflammatory response. In this review information has been compiled concerning the possible mechanisms involved in an increase in obesity, diabetes and kidney dysfunction via the exacerbation of the inflammatory response and its association with gut dysbiosis. In addition, the role of fructooligosaccharides (FOS), a source of prebiotic widely available commercially, on the improvement of gut dysbiosis and attenuation of inflammation on obese and diabetic conditions has been reviewed. The evidence confirms that FOS supplementation could improve the pathological changes associated with obesity and diabetes related kidney disease, however, knowledge concerning the mechanisms involved is still limited and needs further elucidation.

Gut microbes and muscle function: can probiotics make our muscles stronger?

Evidence suggests that gut microbiota composition and diversity can be a determinant of skeletal muscle metabolism and functionality. This is true in catabolic (sarcopenia and cachexia) or anabolic (exercise or in athletes) situations. As gut microbiota is known to be causal in the development and worsening of metabolic dysregulation phenotypes such as obesity or insulin resistance, it can regulate, at least partially, skeletal muscle mass and function. Skeletal muscles are physiologically far from the gut. Signals generated by the gut due to its interaction with the gut microbiome (microbial metabolites, gut peptides, lipopolysaccharides, and interleukins) constitute links between gut microbiota activity and skeletal muscle and regulate muscle functionality via modulation of systemic/tissue inflammation as well as insulin sensitivity. The probiotics able to limit sarcopenia and cachexia or promote health performances in rodents are mainly lactic acid bacteria and bifidobacteria. In humans, the same bacteria have been tested, but the scarcity of the studies, the variability of the populations, and the difficulty to measure accurately and with high reproducibility muscle mass and function have not allowed to highlight specific strains able to optimize muscle mass and function. Further studies are required on more defined population, in order to design personalized nutrition. For elderly, testing the efficiency of probiotics according to the degree of frailty, nutritional state, or degree of sarcopenia before supplementation is essential. For exercise, selection of probiotics capable to be efficient in recreational and/or elite athletes, resistance, and/or endurance exercise would also require further attention. Ultimately, a combination of strategies capable to optimize muscle functionality, including bacteria (new microbes, bacterial ecosystems, or mix, more prone to colonize a specific gut ecosystem) associated with prebiotics and other 'traditional' supplements known to stimulate muscle anabolism (e.g. proteins), could be the best way to preserve muscle functionality in healthy individuals at all ages or patients.

Fatty kidney: A possible future for chronic kidney disease research

BACKGROUND

Metabolic syndrome is a growing twenty-first century pandemic associated with multiple clinical comorbidities ranging from cardiovascular diseases, non-alcoholic fatty liver disease and polycystic ovary syndrome to kidney dysfunction. A novel area of research investigates the concept of fatty kidney in the pathogenesis of chronic kidney disease, especially in patients with diabetes mellitus or metabolic syndrome.

AIM

To review the most updated literature on fatty kidney and provide future research, diagnostic and therapeutic perspectives on a disease increasingly affecting the contemporary world.

MATERIALS AND METHOD

We performed an extensive literature search through three databases including Embase (Elsevier) and the Cochrane Central Register of Controlled Trials (Wiley) and PubMed/Medline Web of Science in November 2021 by using the following terms and their combinations: 'fatty kidney', 'ectopic fat', 'chronic kidney disease', 'cardiovascular event', 'cardio-metabolic risk', 'albuminuria' and 'metabolic syndrome'. Each study has been individually assessed by the authors.

RESULTS

Oxidative stress and inflammation, Klotho deficiency, endoplasmic reticulum stress, mitochondrial dysfunction and disruption of cellular energy balance appear to be the main pathophysiological mechanisms leading to tissue damage following fat accumulation. Despite the lack of large-scale comprehensive studies in this novel field of research, current clinical trials demonstrate fatty kidney as an independent risk factor for the development of chronic kidney disease and cardiovascular events.

CONCLUSION

The requirement for future studies investigating the pathophysiology, clinical outcomes and therapeutics of fatty kidney is clear.

Clinical Efficacy of Persian Medicine Diet Combined with Western Medicine-Based Diet on Proteinuria in Pediatric Nephrotic Syndrome: A Randomized Controlled Clinical Trial

Introduction

Nephrotic syndrome (NS) is a common chronic kidney disorder during childhood. The most important characteristic of this disease is proteinuria. The Persian medicine (PM) has important dietary recommendations for strengthening the kidney function and treatment of this disease. The aim of this study was to investigate the effect of a diet including PM recommendations and general principles of Western medicine.

Materials and Methods

Twenty children with nephrotic syndrome were randomly divided into intervention and control groups and monitored for one month. The control group received a diet based on the general principles of Western medicine. In the intervention group, in addition to the Western medicine diet, dietary recommendations of PM were also prescribed including the pomegranate (Cydonia oblonga mill.), quince (Cydonia oblonga mill.), and whole grains (wheat and barley). A 24-hour dietary questionnaire was applied and anthropometric and biochemical indices including spot urine protein (proteinuria), albumin (Alb), urea, creatinine (Cr), total cholesterol (TC), and triglyceride (TG) were measured before and after the study.

Results

The amount of protein intake reduced significantly in the diet of both groups but the differences between the two groups were not significant. Proteinuria reduced significantly in both the Western and PM groups; however, proteinuria was significantly lower in the Persian medicine group compared to the control group. TC and Cr levels reduced significantly in the intervention group, although the changes were not significant compared to the control group.

Conclusion

The results of this study showed that adding dietary recommendations of the Persian medicine to the general rules of the Western medicine diet reduced proteinuria and improved the combat against nephrotic syndrome.

Saccharomyces boulardii exerts renoprotection by modulating oxidative stress, renin angiotensin system and uropathogenic microbiota in a murine model of diabetes

AIMS

We aimed to investigate whether Saccharomyces boulardii strain might exert renoprotective effects by modulating renal renin angiotensin system, oxidative stress and intestinal microbiota in streptozotocin-diabetic mice.

MAIN METHODS

Thirty-six C57BL/6 male mice were divided into four groups: control (C), control + probiotic (CP), diabetes (D), diabetes + probiotic (DP). Diabetes was induced by one intraperitoneal injection of streptozotocin and Saccharomyces boulardii was administered by oral gavage for 8 weeks. Blood glucose, albuminuria and urinary volume were measured. Renal levels of angiotensin peptides (angiotensin I, II and 1-7) and the activities of angiotensin-converting enzyme (ACE) and ACE2 were determined, besides that, renal morphology, serotonin and dopamine levels and also microbiota composition were analyzed.

KEY FINDINGS

Probiotics significantly increased C-peptide secretion and reduced blood glucose of diabetic animals. Saccharomyces boulardii also improved renal antioxidant defense, restored serotonin and dopamine concentration, and activated the renin-angiotensin system (RAS) vasodilator and antifibrotic axis. The modulation of these markers was associated with a beneficial impact on glomerular structure and renal function of diabetic treated animals. The phenotypic changes induced by Saccharomyces boulardii were also related to modulation of intestinal microbiota, evidenced by the decreased abundance of Proteus and Escherichia-Shigella, considered diabetic nephropathy biomarkers.

SIGNIFICANCE

Therefore, probiotic administration to streptozotocin-induced diabetic mice improves kidney structure and function in a murine model and might represent a reasonable strategy to counteract nephropathy-associated maladaptive responses in diabetes.

The Use of Healthy Eating Index 2015 and Healthy Beverage Index for Predicting and Modifying Cardiovascular and Renal Outcomes

PURPOSE OF REVIEW

With the wide recognition of the importance of dietary patterns rather than isolated nutrient groups on health outcomes, numerous diet quality indices have been designed to evaluate the overall food intake quality in the last two decades.

RECENT FINDINGS

The newest version of the Healthy Eating Index (HEI), HEI-2015, is a diet quality index that measures adherence to the recommendations of the 2015-2020 Dietary Guidelines for Americans. While the key nutrient groups are included in most diet quality indices, differences in other components and the scoring system differentiate HEI. The Healthy Beverage Index (HBI) was recently introduced. Previous literature has confirmed the association of the older versions of HEI with metabolic syndrome, inflammatory markers, and negative health outcomes including cardiovascular disease, type 2 diabetes mellitus, chronic kidney disease, and all-cause mortality. This review presents the existing evidence on the association of HEI-2015 and HBI with health markers and long-term outcome, provides guidance on their use, and identifies persisting challenges such as the development of simple, unified, and objective tools to characterize healthy diets in routine clinical practice.

Microbiota in health and diseases

The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.

The relationship between the gut microbiota, benign prostatic hyperplasia, and erectile dysfunction

Microbiota is defined as the group of commensal microorganisms that inhabit a specific human body site. The composition of each individual's gastrointestinal microbiota is influenced by several factors such as age, diet, lifestyle, and drug intake, but an increasing number of studies have shown that the differences between a healthy microbiota and a dysbiotic one can be related to different diseases such as benign prostatic hyperplasia (BPH) and erectile dysfunction (ED). The aim of this review is to give an overview of the role of the gut microbiota on BPH and ED. Gut microbiota modifications can influence prostate health indirectly by the activation of the immune system and the production of proinflammatory cytokines such as IL-17, IL-23, TNF-alpha, and IFN-gamma, which are able to promote an inflammatory state. Gut dysbiosis may lead to the onset of ED by the alteration of hormone levels and metabolic profiles, the modulation of stress/anxiety-mediated sexual dysfunction, the development of altered metabolic conditions such as obesity and diabetes mellitus, and the development of hypertension. In conclusion, much evidence suggests that the intestinal microbiota has an influence on various pathologies including BPH and ED.