The gut microbiota and the brain-gut-kidney axis in hypertension and chronic kidney disease

Fecal microbiota transplantation modulates myeloid-derived suppressor cells and attenuates renal fibrosis in a murine model

BACKGROUND

Renal fibrosis is a hallmark of progressive chronic kidney disease (CKD), with emerging evidence linking gut microbiota dysbiosis to disease progression. Myeloid-derived suppressor cells (MDSCs) have demonstrated renoprotective effects, yet the impact of fecal microbiota transplantation (FMT) on MDSC-mediated modulation of renal fibrosis remains unclear.

METHODS

C57BL/6J mice underwent unilateral ureteral obstruction (UUO) to induce renal fibrosis, followed by FMT administration via gavage. Flow cytometry was used to quantify granulocytic (G-MDSCs) and monocytic (M-MDSCs) MDSC populations in peripheral blood, kidney, and spleen. To elucidate the role of MDSCs in FMT-mediated effects, MDSCs were depleted or adoptively transferred in vivo. Renal fibrosis severity and inflammatory cytokine expression were subsequently analyzed.

RESULTS

FMT altered MDSC distribution, increasing M-MDSC accumulation in the blood and kidney. This was associated with downregulation of proinflammatory cytokines and attenuation of renal fibrosis. Adoptive MDSC transfer similarly produced anti-inflammatory and antifibrotic effects, reinforcing their therapeutic role in FMT-mediated renal protection.

CONCLUSIONS

FMT enhances M-MDSC-mediated immunomodulation, reducing inflammation and renal fibrosis in UUO-induced CKD. These findings suggest a potential therapeutic strategy targeting the gut-kidney axis in CKD management.

Morroniside alleviates cisplatin-induced renal injury and gut dysbiosis via the gut-kidney axis and ferroptosis

BACKGROUND

The clinical use of cisplatin as a chemotherapeutic agent is limited owing to its nephrotoxicity. Oxidative stress and ferroptosis are responsible for cisplatin-induced renal injury.

PURPOSE

The protective effects of morroniside against cisplatin-induced renal injury were evaluated and its underlying molecular mechanisms were elucidated.

METHODS

An animal model of cisplatin-induced renal injury was established using male C57BL/6 mice. Renal function was assessed by measuring serum creatinine (CRE), uric acid (UA), and blood urea nitrogen (BUN) levels. Antioxidant enzyme activity and pro-inflammatory cytokine levels were determined, and histological studies of renal and colon tissues were performed. Western blotting and immunohistochemical analysis were performed to determine the expression of ferroptosis-related proteins and nuclear factor erythroid 2-related factor (Nrf)2 signaling pathway. Gut microbiota were analyzed using 16S rRNA sequencing. Cisplatin- or erastin-induced renal tubular epithelial cell (HK-2 cells) models were established. Intracellular reactive oxygen species (ROS) levels and mitochondrial membrane potential were measured. The expression of Nrf2, heme oxygenase 1 (HO-1), tumor protein 53 (p53) and glutathione peroxidase (GPX)4 proteins were determined using immunofluorescence.

RESULTS

Morroniside significantly ameliorated cisplatin-induced renal dysfunction, as evidenced by decreased serum CRE, UA, and BUN levels. It reduced pro-inflammatory cytokine levels, enhanced antioxidant enzyme levels, and improved renal and colon histology. Morroniside corrected gut dysbiosis, reduced ROS levels, increased mitochondrial membrane potential, and decreased HK-2 cell apoptosis, alleviating cisplatin- or erastin-induced oxidative stress and ferroptosis.

CONCLUSION

Morroniside mitigated cisplatin-induced renal injury by inhibiting ferroptosis through the GPX4/p53 pathway, reducing oxidative stress via Nrf2/HO-1 axis, and improving gut microbiota dysbiosis, indicating its potential in mitigating cisplatin-induced renal injury.

Integrating microbial GWAS and single-cell transcriptomics reveals associations between host cell populations and the gut microbiome

Microbial genome-wide association studies (GWAS) have uncovered numerous host genetic variants associated with gut microbiota. However, links between host genetics, the gut microbiome and specific cellular contexts remain unclear. Here we use a computational framework, scBPS (single-cell Bacteria Polygenic Score), to integrate existing microbial GWAS and single-cell RNA-sequencing profiles of 24 human organs, including the liver, pancreas, lung and intestine, to identify host tissues and cell types relevant to gut microbes. Analysing 207 microbial taxa and 254 host cell types, scBPS-inferred cellular enrichments confirmed known biology such as dominant communications between gut microbes and the digestive tissue module and liver epithelial cell compartment. scBPS also identified a robust association between Collinsella and the central-veinal hepatocyte subpopulation. We experimentally validated the causal effects of Collinsella on cholesterol metabolism in mice through single-nuclei RNA sequencing on liver tissue to identify relevant cell subpopulations. Mechanistically, oral gavage of Collinsella modulated cholesterol pathway gene expression in central-veinal hepatocytes. We further validated our approach using independent microbial GWAS data, alongside single-cell and bulk transcriptomic analyses, demonstrating its robustness and reproducibility. Together, scBPS enables a systematic mapping of the host-microbe crosstalk by linking cell populations to their interacting gut microbes.

Immunosuppressive drugs and diet interact to modify the gut microbiota and cardiovascular risk factors, and to trigger diabetes

BACKGROUND

Kidney transplant recipients are prescribed an immunosuppressive therapy (IST) and some of them follow a high fat diet (HFD) despite medical recommendations. Both are frequently associated with gut microbiota changes and metabolic disorders. We aimed at precisely identifying the effect of the IST and the HFD on metabolic parameters and the gut microbiota in mice, and at establishing correlations between the latters.

METHODS

8-week-old male mice were treated with IST (a combination of prednisone, mycophenolate mofetil and tacrolimus) or not and were fed HFD or standard chow. Metabolic parameters were measured, and the gut microbiota was explored by the quantification of specific bacterial groups by qPCR and by 16S rDNA sequencing.

RESULTS

The HFD increased insulinemia and decreased the fecal proportion of Bacteroidetes and of Bacteroides. The IST increased systolic blood pressure and the fecal proportion of Escherichia coli. The HFD and the IST administered together resulted in an additive effect on glucose intolerance, high fasting blood glucose, homeostasis model assessment of insulin resistance (HOMA-IR), percentage of fat mass, blood triglyceride, blood cholesterol, and endotoxemia. On the opposite, the HFD and the IST had antagonistic effects on body weight, the proportion of Firmicutes, the Firmicutes/Bacteroidetes ratio, and the proportion of Clostridium leptum, Bifidobacterium, and Lactobacillus in the feces. Finally, we found that the correlations between gut bacterial communities and metabolic consequences of the HFD were altered by the IST.

CONCLUSION

The IST and the HFD have specific consequences on the gut microbiota and metabolism. We hypothesize that the metabolic consequences are at least partially mediated by IST/HFD-induced dysbiosis.

A Bibliometric Analysis of hypertension and anxiety from 2004 to 2022

BACKGROUND

A growing body of clinical evidence points to an association between hypertension and anxiety, but the mechanisms by which the two occur are unclear. This article aims to explore possible common influences and associations between hypertension and anxiety.

METHODS

We searched for publications on hypertension and anxiety from January 01, 2004 to December 31, 2022 in Web of Science and performed bibliometrics using CiteSpace, VOSviewer, Scimago Graphica and Gephi.

RESULTS

A total of 3216 related articles were retrieved from the Web of Science database. After screening, 3051 articles were included. The number of published articles has increased over the past 19 years. The United States has more researches in this area and has strong collaborative relationships with other countries, which gives it some credibility and authority. The words that appear in the burst keywords are gender, age, obesity, depression, panic disorder, pregnancy induced hypertension, coronary heart disease, chronic kidney disease, and pituitary adrenal axi, which are co-related with hypertension and anxiety.

CONCLUSION

There is a link between hypertension and anxiety, and the 2 influence each other, usually in a positive way. Common influences on hypertension and anxiety include age, gender, obesity, depression, panic attacks, pregnancy, coronary heart disease and chronic kidney disease. Recent research hotspots have focused on population aging and comorbidities. Future research hotspots are likely continue to focus on influencing factors, clinical research and prognosis.

Preparation of PEG-modified isoquercitrin liposomes and anti-chronic kidney disease research

The clinical application of Isoquercitrin (IQ) is limited by its low water solubility and short retention time in the body, despite its diverse pharmacological effects. To address these issues, we prepared polyethylene glycol (PEG)-modified IQ liposomes (IQ-L) using the thin film dispersion method and optimized the formulation through a combination of One Factor at a Time (OFAT) method and response surface experiments. Characterization of the IQ-L that was prepared using the optimal formulation revealed a particle size of 185.48 nm, a polydispersity index of 0.252, a zeta potential of -33.88 mV, and an impressive encapsulation efficiency of 97.84%. In vitro release studies showed a significantly higher cumulative release rate for IQ-L compared to free IQ. Pharmacokinetic evaluations in rats demonstrated a 4.54-fold increase in the area under the concentration-time curve, a 1.63-fold prolongation of the half-life, and a 2.07-fold increase in peak concentration for IQ-L compared to unmodified IQ. Moreover, assessments of renal function in a mouse model indicated promising therapeutic effects. In summary, the PEG-modified liposome system greatly improved the solubility and in vivo retention time of IQ, thus making it a potential clinical agent for the treatment of chronic kidney disease (CKD).

Gut microbial signatures associated with uremic pruritus in hemodialysis patients

BACKGROUND

The gut microbiota influences the gut-skin-kidney axis, but its role in uremic pruritus remains poorly understood. This study aimed to explore differences in gut microbial profiles between hemodialysis (HD) patients with and without uremic pruritus and identify potential microbial signatures associated with uremic pruritus.

METHODS

We conducted a cross-sectional study of HD patients with and without uremic pruritus. Stool samples were collected from all participants, and the gut microbiota composition was analyzed using 16S rRNA gene sequencing. Alpha and beta diversity metrics were calculated to assess microbial diversity. LEfSe analysis was performed to identify differentially abundant taxa associated with uremic pruritus.

RESULTS

Among 93 HD patients (mean age: 61.9 years, 31.2 % female), uremic pruritus occurred in 61.3 % of patients, with a median visual analog scale (VAS) score of 4.0. While alpha diversity did not differ significantly between groups, beta diversity analysis revealed significant compositional differences (unweighted UniFrac metric, P = 0.004; weighted UniFrac metric, P < 0.001). LEfSe analysis revealed significant enrichment of the order Pasteurellales, family Pasteurellaceae and genus Dialister in patients with uremic pruritus, whereas the order Corynebacteriales was more abundant in patients without pruritus (P < 0.05, LDA score > 3).

CONCLUSION

In this study, we found significant differences in gut microbiota composition between HD patients with and without uremic pruritus and identified potential microbial biomarkers for uremic pruritus. Further studies are needed to elucidate the underlying mechanisms and explore microbiota-targeted therapeutic interventions.

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.

Mechanisms of action of intestinal microorganisms and advances in head and neck tumors

In the last decade, it has been discovered that intestinal flora can affect various organ-specific cancers by altering the body's energy balance, synthesizing genetic toxins and small signaling molecules, and initiating and modulating immune responses. In this review, we will focus on elucidating the role of intestinal flora based on its molecular mechanisms and its possible impact on head and neck cancers in the near future, and explore how it may be a novel approach to treating head and neck cancers in the future.

Beyond the gut: Unraveling the multifaceted influence of microbiome on cardiovascular health

Cardiovascular disease is one of the leading causes of death worldwide. Even while receiving adequate pharmacological treatment for their hypertension, people are nonetheless at greater risk for cardiovascular disease. There is growing evidence that the gut microbiota may have major positive and negative effects on blood pressure and illnesses related with it as more study into this topic is conducted. Trimethylamine n-oxide (TMAO) and short-chain fatty acids (SCFA) are two major by-products of the gut microbiota. TMAO is involved in the formation of other coronary artery diseases, including atherosclerosis and hypertension, while SCFAs play an important role in controlling blood pressure. Numerous investigations have confirmed the established link between dietary salt intake and hypertension. Reducing sodium in the diet is linked to lower rates of cardiovascular disease morbidity and mortality as well as lower rates of blood pressure and hypertension. In both human and animal research, high salt diets increase local and systemic tissue inflammation and compromise gut architecture. Given that the gut microbiota constantly interacts with the immune system and is required for the correct maturation of immune cells, it is scientifically conceivable that it mediates the inflammatory response. This review highlights the therapeutic possibilities for focusing on intestinal microbiomes as well as the potential functions of the gut microbiota and its metabolites in the development of hypertension.

Research progress on the kidney-gut-brain axis in brain dysfunction in maintenance hemodialysis patients

Maintenance hemodialysis (MHD) has become the primary renal replacement therapy for patients with end-stage renal disease. The kidney-gut-brain axis represents a communication network connecting the kidney, intestine and brain. In MHD patients, factors such as uremic toxins, hemodynamic changes, vascular damage, inflammation, oxidative stress, and intestinal dysbiosis in MHD patients refers to a range of clinical syndromes, including brain injury, and is manifested by conditions such as white matter disease, brain atrophy, cerebrovascular disease, cognitive impairment, depression, anxiety, and other behavioral or consciousness abnormalities. Numerous studies have demonstrated the prevalence of these brain disorders in MHD patients. Understanding the mechanisms of brain disorders in MHD patients, particularly through the lens of kidney-gut-brain axis dysfunction, offers valuable insights for future research and the development of targeted therapies. This article reviews the brain dysfunction associated with MHD, the impact of the kidney-brain axis, intestinal barrier damage, gut microbiota dysbiosis caused by MHD, and the role of the gut-brain axis in brain dysfunction.

The influence of microplastics on hypertension-associated cardiovascular injury via the modulation of gut microbiota

Microplastics (MPs) have been found to interfere with the gut microbiota and compromise the integrity of the gut barrier. Excessive exposure to MPs markedly elevates the risk of cardiovascular disease, yet their influence on hypertension remains elusive, calling for investigation into their potential impacts on blood pressure (BP) regulation. In the present study, an increase in the concentration of MPs was observed in the fecal samples of individuals suffering from hypertension, as compared to the controls. Oral administration of MPs led to obvious increases in systolic, diastolic and mean BP levels in mice. MPs were associated with promoting myocardial hypertrophy, fibrosis, and cardiac remodeling through alterations in gut microbial composition, such as Prevotella and Coprobacillus, or fecal metabolites Betaine and Glycyrrhetinic acid. The hypertensive damage mediated by MPs was significantly mitigated by the high-fiber diet or antibiotics that targeted the gut microbiota. Notablely, fecal microbiota transplantation from mice treated with MPs led to an increase in systolic BP levels and the development of cardiac dysfunction. Our findings offer valuable insights into the complex interplay between MPs and the gut microbiome in the context of hypertension, and suggest potential strategies for reducing the vascular and cardiac injury caused by MPs.

Phenylethanol Glycosides from Cistanche tubulosa Modulate the Gut Microbiota and Cecal Metabolites to Ameliorate Diabetic Nephropathy Induced by Streptozotocin Combined with High-Fat Diet in Rats

Diabetic nephropathy (DN) is a prevalent complication and serious microvascular of diabetes mellitus. After previous studies, we found that phenylethanol glycosides (CPhGs) derived from Cistanche tubulosa (Schenk) Wight exerts antidiabetic and renoprotective effects. However, the effects of CPhGs on DN remain incompletely understood. The study aimed to examine the effects of CPhGs on DN in rats and explore the underlying mechanism involved. A DN rat model was established by streptozotocin (STZ) combined with a high-fat diet. Reagent kits were used to assess the extent to which CPhGs ameliorate hyperglycemia, insulin resistance (IR), renal dysfunction, kidney oxidative stress, and peripheral inflammation. Histology and immunohistochemical staining were used to detect the changes in renal tissue structure and the expression levels of α-smooth muscle actin (α-SMA) and collagen I. Furthermore, we analyzed the cecal contents of DN rats to investigate the effect of CPhGs on gut microbiota by using 16S rRNA sequencing and broad-spectrum metabolite profiling. The results showed that CPhGs demonstrated a range of advantageous outcomes in DN, encompassing the enhancement of kidney function and alleviation of hyperglycemia, IR, renal injury, oxidative stress, and peripheral inflammatory reactions. In addition, CPhGs regulated the abundance of the [Eubacterium]_coprostanoligenes_group, Oscillospiraceae_UCG-005, etc. to modulate the gut microbiota. CPhGs significantly upregulated the content of vitamin B6 and tyrosyl-tryptophan and downregulated histamine, L-methionine, etc. In summary, the therapeutic efficacy of CPhGs on DN rats may be achieved by modulating the gut microbiota and cecal metabolites to restore the metabolic disorders of vitamin B6, histidine, etc.

Advances in kidney disease: pathogenesis and therapeutic targets

Chronic kidney disease (CKD) is a global public health issue characterized by progressive loss of kidney function, of which end-stage kidney disease (ESKD) is the last stage. The global increase in the prevalence of CKD is linked to the increasing prevalence of traditional risk factors, including obesity, hypertension, and diabetes mellitus, as well as metabolic factors, particularly insulin resistance, dyslipidemia, and hyperuricemia. Mortality and comorbidities, such as cardiovascular complications, rise steadily as kidney function deteriorates. Patients who progress to ESKD require long-term kidney replacement therapy, such as transplantation or hemodialysis/peritoneal dialysis. It is currently understood that a crucial aspect of CKD involves persistent, low-grade inflammation. In addition, increased oxidative and metabolic stress, endothelial dysfunction, vascular calcification from poor calcium and phosphate metabolism, and difficulties with coagulation are some of the complex molecular pathways underlying CKD-related and ESKD-related issues. Novel mechanisms, such as microbiome dysbiosis and apolipoprotein L1 gene mutation, have improved our understanding of kidney disease mechanisms. High kidney disease risk of Africa has been linked to APOL1 high-risk alleles. The 3-fold increased risk of ESKD in African Americans compared to European Americans is currently mainly attributed to variants in the APOL1 gene in the chromosome 22q12 locus. Additionally, the role of new therapies such as SGLT2 inhibitors, mineralocorticoid receptor antagonists, and APOL1 channel function inhibitors offers new therapeutic targets in slowing down the progression of chronic kidney disease. This review describes recent molecular mechanisms underlying CKD and emerging therapeutic targets.

Relationship between dietary consumption of live microbes with mortality in adults with chronic kidney disease

BACKGROUND

The connection between gut dysbiosis and chronic kidney disease (CKD) has been recognized, but, the effect of dietary intake of live microbes on the prognosis of CKD is still unclear. This analysis examined the relationship of dietary live microbe intake with mortality among adults with CKD.

METHODS

For this study, information was gathered from the National Health and Nutrition Examination Survey 1999-2018, which included 8725 adult participants with CKD. MedHi refers to the live microbial content of food beyond 104 CFU/g. To elucidate the link between MedHi dietary live microbe intake and mortality from all-cause and cardiovascular disease (CVD), we implemented a weighted multivariate Cox regression analysis.

RESULTS

In contrast to survivors, non-survivors had a lower intake of dietary live microbes. The findings from the multivariable model indicated a negative and linear relationship between an increment of 100 g in MedHi foods and reduced mortality from all-causes and CVD. Likewise, participants in the highest MedHi food group exhibited a 20% and 26% decreased risk of all-cause and CVD mortality, respectively, compared to those in the lowest MedHi food group. Stratified analyses conducted on various subgroups yielded consistent findings.

CONCLUSION

A significant inverse linear relationship was found between high dietary live microbe consumption and reduced all-cause and CVD mortality.

Mechanisms Associated With Renal Injury in Hyperuricemia and Strategies for the Development of Natural Active Substances

Hyperuricemia (HUA) is a metabolic condition resulting from an abnormality in the process of purine metabolism. Its occurrence has been on the rise globally. The results of relevant studies show that 5% to 12% of HUA patients will eventually develop gout, and one-third of these patients may involve the kidneys and develop kidney disease. Although the severe renal health hazards associated with excessive uric acid levels are well known, the specific molecular mechanisms remain unknown. Therefore, this paper provides insights into the mechanisms and related chain reactions of HUA leading to renal injury from three perspectives: imbalance of intestinal homeostasis, oxidative stress response, and NLRP3 inflammasome. In addition, standing against the background of the strong side effects and high tolerability disadvantages of commercially available uric acid-lowering drugs such as allopurinol, benzbromarone, and febuxostat, the development of a new active anti-hyperuricemic drug with fewer side effects is justified. This article reviews the progress of research on natural actives (probiotics, dietary polyphenols, peptides) with a high safety profile, multi-targeting, and integrative modulatory effects, in an attempt to provide some ideas for drug developers.

Advocacy for DOHaD research optimizing child kidney health

Emerging antenatal risk factors have been associated with an increased risk of kidney disease throughout the offspring's life course. However, the intricate kidney programming mechanisms underlying these risks remain complex and are incompletely understood, but they are rooted in structural and functional alterations within the kidneys. The Developmental Origins of Health and Disease (DOHaD) theory underscores the significance of elucidating core mechanisms initiated through the maternal-fetal interface, which trigger kidney programming. Furthermore, it offers a promising avenue for preventing kidney disease at its earliest stages through a process known as reprogramming. This concise review aims to synthesize existing knowledge regarding the impact of kidney programming on offspring kidney disease and to provide an overview of documented reprogramming strategies as observed in animal models of kidney programming. By consolidating this information, we aim to expedite the translation of research breakthroughs into practical clinical solutions, ultimately resulting in enhanced outcomes for children facing kidney-related issues.

Navigating the microbial maze: unraveling the connection between gut microbiome and pediatric kidney and urinary tract disease

The gut microbiome is made up of trillions of bacteria, viruses, archaea, and microbes that play a significant role in the maintenance of normal physiology in humans. Recent research has highlighted the effects of the microbiome and its dysbiosis in the pathogenesis and maintenance of kidney disease, especially chronic kidney disease (CKD) and its associated cardiovascular disease. While studies have addressed the kidney-microbiome axis in adults, how dysbiosis may uniquely impact pediatric kidney disease patients is not well-established. This narrative review highlights all relevant studies focusing on the microbiome and pediatric kidney disease that were published between 7/2015 and 7/2023. This review highlights pediatric-specific considerations including growth and bone health as well as emphasizing the need for increased pediatric research. Understanding microbiome-kidney interactions may allow for novel, less invasive interventions such as dietary changes and the use of probiotics to improve preventive care and ameliorate long-term morbidity and mortality in this vulnerable population.

Gut-X axis

Recent advances in understanding the modulatory functions of gut and gut microbiota on human diseases facilitated our focused attention on the contribution of the gut to the pathophysiological alterations of many extraintestinal organs, including the liver, heart, brain, lungs, kidneys, bone, skin, reproductive, and endocrine systems. In this review, we applied the "gut-X axis" concept to describe the linkages between the gut and other organs and discussed the latest findings related to the "gut-X axis," including the underlying modulatory mechanisms and potential clinical intervention strategies.

A study on the effect of blue light on kidney stone formation in rats via the brain-kidney axis

Kidney stones, a common urological disease, may involve the brain-kidney axis in their formation, though the specific mechanism remains unclear. This study aimed to investigate the effects of blue light on relevant metabolic indicators and oxidative stress status in rats with kidney stones through the brain-kidney axis. A rat model of kidney stones was established by administering 1% ethylene glycol and 2% ammonium chloride. Subsequently, blue light intervention was applied, and the outcomes were compared with those of a control group of normal rats. Our findings revealed that rats with kidney stones receiving blue light intervention exhibited significantly increased levels of antidiuretic hormone, intensified oxidative stress response, and augmented stone formation compared to kidney stone rats without blue light intervention. However, in normal rats, blue light intervention did not cause significant changes in these indicators. In summary, this study indicates that under pathological conditions, blue light may promote the secretion of antidiuretic hormone in serum and enhance oxidative stress response in renal tissues by affecting the brain-kidney axis, thereby accelerating the formation of kidney stones in rats.

Codonopsis pilosula polysaccharide alleviates ulcerative colitis by modulating gut microbiota and SCFA/GPR/NLRP3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Codonopsis pilosula (Franch.) Nannf. (CP) is a Chinese herb commonly used in traditional Chinese medicine to treat ulcerative colitis (UC). C. pilosula polysaccharide (CPPS) is an important bioactive compound in CP. Polysaccharides are degraded by and interact with the gut microbiota, exerting therapeutic effects. However, the mechanism of action of CPPS in treating UC by regulating gut microbiota is unclear.

AIM OF THE STUDY

This study aimed to elucidate the therapeutic efficacy of CPPS on UC mice and its mechanism of action.

MATERIALS AND METHODS

Size-exclusion chromatography with multi-angle laser-light scattering and refractive index analysis was employed to ascertain the molecular weight of CPPS, while its monosaccharide composition was determined using ion chromatography. An experimental colitis mouse model was induced by administering 3% (dextran sulfate sodium) DSS in drinking water for five consecutive days. Three doses of CPPS were administered to evaluate their therapeutic effects on UC. CPPS was administered for seven days, and salicylazosulfapyridine was used as a positive control. Inflammatory cytokine secretion in the colon tissue was measured, and histopathological evaluation was performed on colon sections. Alterations in the abundance of the intestinal microbiota species were also analyzed. We then quantified short-chain fatty acids (SCFAs) in the cecal content and verified the G protein-coupled receptor (GPR)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) pathways using Western blot. Furthermore, the ameliorative effect of gut microbiota on DSS-induced UC symptoms was verified using the fecal microbiota transplantation (FMT) experiment.

RESULTS

CPPS comprised of rhamnose, arabinose, galactose, glucose, and galacturonic acid. CPPS significantly alleviated DSS-induced UC. Compared to the DSS group, CPPS treatment significantly increased the ratio of the Firmicutes to the Bacteroidetes and upregulated the abundance of beneficial bacteria such as g__Ligilactobacillus, g_Akkermansia, g_Faecalibaculum, g_Odoribacter. The release of acetic acid and butyric acid were further promoted. CPPS can inhibit NLRP3 activation by binding SCFAs to GPR proteins, thereby reducing intestinal inflammation. FMT confirmed that the gut microbiota in the CPPS-trans group sufficiently mitigated DSS-induced UC symptoms.

CONCLUSIONS

CPPS ameliorates the symptoms of DSS-induced UC primarily through the gut microbiota modulation and SCFA/GPR/NLRP3 pathways, making it a promising candidate for UC treatment.

Epigenome-wide association study of Chinese monozygotic twins identifies DNA methylation loci associated with estimated glomerular filtration rate

BACKGROUND

DNA methylation (DNAm) has been shown in multiple studies to be associated with the estimated glomerular filtration rate (eGFR). However, studies focusing on Chinese populations are lacking. We conducted an epigenome-wide association study to investigate the association between DNAm and eGFR in Chinese monozygotic twins.

METHODS

Genome-wide DNAm level was detected using Reduced Representation Bisulfite Sequencing test. Generalized estimation equation (GEE) was used to examine the association between Cytosine-phosphate-Guanines (CpGs) DNAm and eGFR. Inference about Causation from Examination of FAmiliaL CONfounding was employed to infer the causal relationship. The comb-p was used to identify differentially methylated regions (DMRs). GeneMANIA was used to analyze the gene interaction network. The Genomic Regions Enrichment of Annotations Tool enriched biological functions and pathways. Gene expression profiling sequencing was employed to measure mRNA expression levels, and the GEE model was used to investigate the association between gene expression and eGFR. The candidate gene was validated in a community population by calculating the methylation risk score (MRS).

RESULTS

A total of 80 CpGs and 28 DMRs, located at genes such as OLIG2, SYNGR3, LONP1, CDCP1, and SHANK1, achieved genome-wide significance level (FDR < 0.05). The causal effect of DNAm on eGFR was supported by 12 CpGs located at genes such as SYNGR3 and C9orf3. In contrast, the causal effect of eGFR on DNAm is proved by 13 CpGs located at genes such as EPHB3 and MLLT1. Enrichment analysis revealed several important biological functions and pathways related to eGFR, including alpha-2A adrenergic receptor binding pathway and corticotropin-releasing hormone receptor activity pathway. GeneMANIA results showed that SYNGR3 was co-expressed with MLLT1 and had genetic interactions with AFF4 and EDIL3. Gene expression analysis found that SYNGR3 expression was negatively associated with eGFR. Validation analysis showed that the MRS of SYNGR3 was positively associated with low eGFR levels.

CONCLUSIONS

We identified a set of CpGs, DMRs, and pathways potentially associated with eGFR, particularly in the SYNGR3 gene. These findings provided new insights into the epigenetic modifications related to the decline in eGFR and chronic kidney disease.

Biomimetic wrinkled prebiotic microspheres with enhanced intestinal retention for hyperphosphatemia and vascular calcification

It is urgent for patients with chronic kidney disease (CKD) to develop a robust and facile therapy for effective control of serum phosphate and reasonable regulation of gut microbiota, which are aiming to prevent cardiovascular calcification and reduce cardiovascular complications. Here, bioinspired by intestinal microstructures, we developed biomimetic wrinkled prebiotic-containing microspheres with enhanced intestinal retention and absorption for reducing hyperphosphatemia and vascular calcification of CKD model rats. The resultant CSM@5 microspheres exhibited favorable phosphate binding capacity in vitro and could effectively reduce serum concentration of phosphorous in vivo. Through increasing the beneficial bacteria and decreasing the harmful bacteria in the intestinal tract, these prebiotic microspheres can modulate intestinal microbiota and then ameliorate vascular calcification notably. This feasible and robust approach may offer a potential and effective strategy for the treatment of hyperphosphatemia of CKD and prevention of its cardiovascular complications.

Blood Pressure Management Strategies and Podocyte Health

Hypertension (HTN) is one of the key global cardiovascular risk factors, which is tightly linked to kidney health and disease development. Podocytes, glomerular epithelial cells that play a pivotal role in maintenance of the renal filtration barrier, are significantly affected by increased glomerular capillary pressure in HTN. Damage or loss of these cells causes proteinuria, which marks the initiation of the HTN-driven renal damage. It goes without saying that effective blood pressure (BP) management should not only mitigate cardiovascular risks but also preserve renal function by protecting podocyte integrity. This review offers a comprehensive examination of current BP management strategies and their implications for podocyte structure and function and emphasizes strategies for the reduction of proteinuria in HTN. We explore primary and secondary antihypertensive agents, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, and diuretics, as well as newer therapies (sodium-glucose cotransporter-2 blocking and endothelin receptor antagonism), emphasizing their mechanistic roles in safeguarding podocytes and curtailing proteinuria.

Sex differences in gut microbiota, hypertension, and cardiovascular risk

The intricate ecosystem of the gut microbiome exhibits sex-specific differences, influencing the susceptibility to cardiovascular diseases (CVD). Imbalance within the gut microbiome compromises the gut barrier, activates inflammatory pathways, and alters the production of metabolites, all of which initiate chronic diseases including CVD. In particular, the interplay between lifestyle choices, hormonal changes, and metabolic byproducts uniquely affects sex-specific gut microbiomes, potentially shaping the risk profiles for hypertension and CVD differently in men and women. Understanding the gut microbiome's role in CVD risk offers informative reasoning behind the importance of developing tailored preventative strategies based on sex-specific differences in CVD risk. Furthermore, insight into the differential impact of social determinants and biological factors on CVD susceptibility emphasizes the necessity for more nuanced approaches. This review also outlines specific dietary interventions that may enhance gut microbiome health, offering a glimpse into potential therapeutic avenues for reducing CVD risk that require greater awareness. Imbalance in natural gut microbiomes may explain etiologies of chronic diseases; we advocate for future application to alter the gut microbiome as possible treatment of the aforementioned diseases. This review mentions the idea of altering the gut microbiome through interventions such as fecal microbiota transplantation (FMT), a major application of microbiome-based therapy that is first-line for Clostridium difficile infections and patient-specific probiotics highlights more innovative approaches to hypertension and CVD prevention. Through increased analysis of gut microbiota compositions along with patient-centric probiotics and microbiome transfers, this review advocates for future preventative strategies for hypertension.

A metagenome-wide study of the gut virome in chronic kidney disease

Rationale: Chronic kidney disease (CKD) is a progressively debilitating condition leading to kidney dysfunction and severe complications. While dysbiosis of the gut bacteriome has been linked to CKD, the alteration in the gut viral community and its role in CKD remain poorly understood. Methods: Here, we characterize the gut virome in CKD using metagenome-wide analyses of faecal samples from 425 patients and 290 healthy individuals. Results: CKD is associated with a remarkable shift in the gut viral profile that occurs regardless of host properties, disease stage, and underlying diseases. We identify 4,649 differentially abundant viral operational taxonomic units (vOTUs) and reveal that some CKD-enriched viruses are closely related to gut bacterial taxa such as Bacteroides, [Ruminococcus], Erysipelatoclostridium, and Enterocloster spp. In contrast, CKD-depleted viruses include more crAss-like viruses and often target Faecalibacterium, Ruminococcus, and Prevotella species. Functional annotation of the vOTUs reveals numerous viral functional signatures associated with CKD, notably a marked reduction in nicotinamide adenine dinucleotide (NAD+) synthesis capacity within the CKD-associated virome. Furthermore, most CKD viral signatures are reproducible in the gut viromes of diabetic kidney disease and several other common diseases, highlighting the considerable universality of disease-associated viromes. Conclusions: This research provides comprehensive resources and novel insights into the CKD-associated gut virome, offering valuable guidance for future mechanistic and therapeutic investigations.

The evolving understanding of systemic mechanisms in organ-specific IgA nephropathy: a focus on gut-kidney crosstalk

The interplay between multiple organs, known as inter-organ crosstalk, represents a complex and essential research domain in understanding the mechanisms and therapies for kidney diseases. The kidneys not only interact pathologically with many other organs but also communicate with other systems through various signaling pathways. It is of paramount importance to comprehend these mechanisms for the development of more efficient therapeutic strategies. Despite extensive research in IgA nephropathy (IgAN), the most common kidney disease, the elaboration mechanism of IgAN remains challenging. Numerous studies suggest that alterations in the intestinal microbiome and its metabolites are pivotal in the progression of IgAN, opening new avenues for understanding its mechanisms. Interestingly, certain presumed probiotics, such as Akkermansia muciniphila, have been implicated in the onset of IgAN, making the exploration of gut microbiota in the context of IgAN pathogenesis even more intriguing. In this review, we summarize the status of gut microbiology studies of IgAN and explore the possible mechanisms and intervention prospects. Future research and treatment directions may increasingly emphasize systemic, multi-organ combined interventions to decelerate the advancement of kidney disease and enhance the overall prognosis of patients.

Metagenomics and metabolomics to investigate the effect of Amygdalus mongolica oil on intestinal microbiota and serum metabolites in rats

BACKGROUND

Renal fibrosis (RF) is an inevitable consequence of multiple manifestations of progressive chronic kidney diseases (CKDs). Mechanism of Amygdalus mongolica (Maxim.) in the treatment of RF needs further investigation.

PURPOSE

The study further investigated the potential mechanism of A. mongolica in the treatment of RF.

METHODS

A rat model of RF was induced by unilateral ureteral obstruction (UUO), followed by treatment with varying dosages of A. mongolica oil for 4 weeks. Body weight was measured weekly. We detected serum levels of interleukin (IL)-6, IL-1β, type Ⅲ procollagen (Col-Ⅲ), type IV collagen (Col-Ⅳ), laminin (LN), hyaluronidase (HA), and tissue levels of albumin (ALB), blood urea nitrogen (BUN), creatinine (Cre), superoxide dismutase (SOD), malondialdehyde (MDA), and hydroxyproline (HYP). Shotgun metagenomics analyzed the composition of the intestinal microbiota. High-performance liquid chromatography coupled with a quadrupole-exactive mass spectrometer (HPLC-Q-Exactive-MS) monitored changes in metabolite levels in serum and gut. Multiple reaction monitoring-mass spectrometry (MRM-MS) determined the levels of amino acids in serum.

RESULTS

A. mongolica oil significantly alleviated indicators related to RF (p < 0.05). A. mongolica oil reduced the ratio of Firmicutes to Bacteroidetes and restored the balance of intestinal microbiota in rats with RF. A. mongolica oil modulated levels of metabolites in gut content and serum. It regulated 11 metabolic pathways including arachidonic acid metabolism. Targeted metabolomics of amino acids showed that 17 amino acids were significantly changed by A. mongolica oil, including L-glycine, L-serine and L-glutamine.

CONCLUSION

A. mongolica oil regulates intestinal microbiota and metabolites, restoring amino acid metabolism to treat RF.

Alterations in gut-derived uremic toxins before the onset of azotemic chronic kidney disease in cats

BACKGROUND

Although gut-derived uremic toxins are increased in azotemic chronic kidney disease (CKD) in cats and implicated in disease progression, it remains unclear if augmented formation or retention of these toxins is associated with the development of renal azotemia.

OBJECTIVES

Assess the association between gut-derived toxins (ie, indoxyl-sulfate, p-cresyl-sulfate, and trimethylamine-N-oxide [TMAO]) and the onset of azotemic CKD in cats.

ANIMALS

Forty-eight client-owned cats.

METHODS

Nested case-control study, comparing serum and urine gut-derived uremic toxin abundance at 6-month intervals between initially healthy cats that developed azotemic CKD (n = 22) and a control group (n = 26) that remained healthy, using a targeted metabolomic approach.

RESULTS

Cats in the CKD group had significantly higher serum indoxyl-sulfate (mean [SD], 1.44 [1.06] vs 0.83 [0.46]; P = .02) and TMAO (mean [SD], 1.82 [1.80] vs 1.60 [0.62]; P = .01) abundance 6 months before the detection of azotemic CKD. Furthermore, logistic regression analysis indicated that indoxyl-sulfate (odds ratio [OR]: 3.2; 95% confidence interval [CI]: 1.2-9.0; P = .04) and TMAO (OR: 3.9; 95% CI: 1.4-11; P = .03) were predictors for the onset of azotemia 6 months before diagnosis. However, renal function biomarkers creatinine, symmetric dimethylarginine, and urinary specific gravity were significantly correlated with indoxyl-sulfate and TMAO abundance, causing a loss in predictive significance after correction for these factors.

CONCLUSIONS

Impaired gut-derived uremic toxin handling is apparent at least 6 months before the diagnosis of azotemia, likely reflecting an already ongoing decrease in GFR, tubular function, or both. A direct causal relationship between gut-derived uremic toxicity and the initiation of CKD in cats is still lacking.

Genetically Predicted Causal Relationship between Gut Microbiota and Various Kidney Diseases

Introduction

Although recent research suggests that alterations in gut microbiota play a critical role in the pathophysiology of kidney diseases, the causal relationship between specific intestinal flora and the risk of kidney diseases remains unclear. Here, we investigated the causal relationship between gut microbiota and different kidney diseases through mendelian randomization analysis.

Methods

Gut microbiota and three types of kidney diseases, including diabetic nephropathy, IgA nephropathy, and membranous nephropathy, were identified from large-scale genome-wide association studies summary data. Inverse variance weighted method was employed to estimate causal relationships. Cochran's Q test was utilized to uncover any heterogeneity. The mendelian randomization-Egger intercept test was employed to detect horizontal pleiotropy, and the leave-one-out method was used for testing the stability. In addition, the reverse, multivariable, and two-step mendelian randomization analysis was conducted to assess the causation possibilities. Furthermore, the associations between three types of kidney diseases and immune infiltration were determined.

Results

We identified 1,531 single-nucleotide polymorphisms. There were 6 positive and 9 negative causal effects between gut microbiota and three types of kidney diseases. Specifically, Dialister was a protective factor for diabetic nephropathy while Lachnospiraceae UCG-008 was a risk factor. Clostridium innocuum was a protective factor for IgA nephropathy, while Christensenellaceae R.7, Clostridium sensu stricto1, Lachnospiraceae UCG-004, Lachnospiraceae UCG-010, Oscillospira, Ruminococcaceae UCG-010, and Terrisporobacter were risk factors for IgA nephropathy. Butyricicoccus, Catenibacterium, Flavonifractor, and Lachnospira were associated with an increased risk of membranous nephropathy, while Ruminococcaceae UCG-011 was associated with a decreased risk of membranous nephropathy. Sensitivity analysis indicated the results were robust. No significant pleiotropy or heterogeneity was identified. Notably, the reverse mendelian randomization analysis did not reveal any causal relationship. After adjusting for environmental confounders, including CO, PM 2.5, PM 10, and exposure to tobacco smoke at home, these causal relationships still exist. Additionally, immune infiltration analysis indicated unique immune cell distribution in each type of kidney disease, which are largely consistent with later two-step approach, emphasizing the significance of immunological processes in the diseases.

Conclusion

This study uncovered the causal relationship between gut microbiota and three types of kidney diseases. This discovery provides fresh perspectives on how microbes contribute to kidney diseases, paving the way for more in-depth clinical studies.

Identification and Bioactivity Analysis of a Novel Bacillus Species, B. maqinnsis sp. nov. Bos-x6-28, Isolated from Feces of the Yak (Bos grunniens)

Background: The identification of novel bacterial species from the intestines of yaks residing on the Qinghai-Tibet Plateau is pivotal in advancing our understanding of host-microbiome interactions and represents a promising avenue for microbial drug discovery. Methods: In this study, we conducted a polyphasic taxonomic analysis and bioactive assays on a Bacillus strain, designated Bos-x6-28, isolated from yak feces. Results: The findings revealed that strain Bos-x6-28 shares a high 16S rRNA gene sequence similarity (98.91%) with B. xiamenensis HYC-10T and B. zhangzhouensis DW5-4T, suggesting close phylogenetic affinity. Physiological and biochemical characterizations demonstrated that Bos-x6-28 could utilize nine carbon sources, including D-galactose, inositol, and fructose, alongside nine nitrogen sources, such as threonine, alanine, and proline. Analysis of biochemical markers indicated that Bos-x6-28's cell wall hydrolysates contained mannose, glucose, and meso-2,6-diaminopimelic acid, while menaquinone-7 (MK-7), phosphatidylethanolamine (PE), phosphatidylcholine (PC), and phosphatidylglycerol (DPG) were found in the cell membrane. The primary cellular fatty acids included C16:0 (28.00%), cyclo-C17:0 (19.97%), C14:0 (8.75%), cyclo-C19:0 (8.52%), iso-C15:0 (5.49%), anteiso-C15:0 (4.61%), and C12:0 (3.15%). Whole-genome sequencing identified a genome size of 3.33 Mbp with 3353 coding genes. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses confirmed Bos-x6-28 as a novel species, hereby named B. maqinnsis Bos-x6-28 (MCCC 1K09379). Further genomic analysis unveiled biosynthetic gene clusters encoding bioactive natural compounds, including β-lactones, sactipeptides, fengycin, and lichenysin analogs. Additionally, in vitro assays demonstrated that this strain exhibits antibacterial and cytotoxic activities. Conclusions: These findings collectively indicate the novel Bacillus species B. maqinnsis Bos-x6-28 as a promising source for novel antibiotic and antitumor agents.

Kidney Programming and Hypertension: Linking Prenatal Development to Adulthood

The complex relationship between kidney disease and hypertension represents a critical area of research, yet less attention has been devoted to exploring how this connection develops early in life. Various environmental factors during pregnancy and lactation can significantly impact kidney development, potentially leading to kidney programming that results in alterations in both structure and function. This early programming can contribute to adverse long-term kidney outcomes, such as hypertension. In the context of kidney programming, the molecular pathways involved in hypertension are intricate and include epigenetic modifications, oxidative stress, impaired nitric oxide pathway, inappropriate renin-angiotensin system (RAS) activation, disrupted nutrient sensing, gut microbiota dysbiosis, and altered sodium transport. This review examines each of these mechanisms and highlights reprogramming interventions proposed in preclinical studies to prevent hypertension related to kidney programming. Given that reprogramming strategies differ considerably from conventional treatments for hypertension in kidney disease, it is essential to shift focus toward understanding the processes of kidney programming and its role in the development of programmed hypertension.

The role for ω-3 polyunsaturated and short chain fatty acids in hypertension: An updated view on the interaction with gut microbiota

As of 2024, arterial hypertension is still considered the leading modifiable cardiovascular risk factor and, due to high rates of undertreatment and poor blood pressure control, the major contributor to human morbidity and mortality. Development of new treatment options and better interventions in lifestyle correction have become a priority of experimental and clinical research. In the last decades, dietary supplementation of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and generation of gut microbiota-derived short chain fatty acids (SCFAs) have surged as potential and promising interventions for hypertension and cardiovascular prevention. ω-3 PUFAs are considered "essential" fatty acids that can be obtained only from dietary sources. Although previous intervention trials were not consistent in reporting a significant benefit of ω-3 PUFAs, the recent REDUCE-IT trial has provided robust evidence in support of their role in cardiovascular prevention. Recent studies have also identified the intestinal microbiota as a potential player in the pathophysiology and progression of hypertension. Although this might occur through many pathways, generation of SCFAs that is highly dependent on dietary fiber intake is primarily involved, providing an additional target for the development of novel therapeutic strategies. For these reasons, some scientific societies currently recommend dietary supplementation of ω-3 PUFAs and fiber-containing foods in patients with hypertension. In this narrative review, we summarize the results of studies that examined the effects of ω-3 PUFAs and SCFAs on blood pressure, highlighting the mechanisms of action on the vascular system and their possible impact on hypertension, hypertension-related organ damage and, ultimately, cardiovascular outcomes.

Gut microbiota regulates oxidative stress and inflammation: a double-edged sword in renal fibrosis

Gut microbiota is a complex and dynamic system that plays critical roles in human health and various disease. Progressive chronic kidney disease (CKD) suggests that patients irreversibly progress to end-stage kidney disease and need renal replacement treatments, including dialysis and transplantation. Ample evidence indicates that local oxidative stress and inflammation play pivotal roles in the pathogenesis and progression of CKD and dysbiosis of gut microbiota. CKD is always accompanied by intestinal inflammation and oxidative stress, which lead to rapid systemic translocation of bacterial-derived uraemic toxins, including indoxyl sulphate, phenyl sulphate and indole-3-acetic acid, and the consequent development and aggravation of renal fibrosis. Although inflammation and oxidative stress have been extensively discussed, there is a paucity of reports on the effects of gut microbiota on renal fibrosis and gut microbiota mediation of oxidative stress and inflammation. This review provides an overview of gut microbiota on inflammation and oxidative stress in renal fibrosis, briefly discusses regulation of the gut flora using microecological preparations and natural products, such as resveratrol, curcumin and emodin as treatments for CKD, and provides a clear pathophysiological rationale for the design of promising therapeutic strategies.

Role of the gut microbiota in cefoperazone/sulbactam-induced epilepsy in mice with chronic renal failure

OBJECTIVES

The mechanism of cefoperazone/sulbactam-induced epilepsy in chronic kidney disease (CKD) patients is not yet clear. We hypothesized that cefoperazone/sulbactam-induced epilepsy could be based on two main factors: neurotoxicity caused by drug accumulation after renal failure and an abnormal gut microbiota (GM).

METHODS

A chronic renal failure (CRF) model in mice was established, and then different doses of cefoperazone/sulbactam were injected to induce epilepsy in mice. Normal mouse feces for fecal microbiota transplantation (FMT) were collected. We observed the changes in feces, mental state, and activity of each group of mice. After killing, we collected kidneys and colon for H&E staining. We collected mouse feces for the 16S RNA sequencing of bacteria.

RESULTS

All CRF mice injected with different concentrations of cefoperazone/sulbactam experienced grade-V seizures and eventually died, whereas normal control mice did not. However, after FMT intervention, the time of epilepsy onset and death in mice was delayed. Early FMT intervention resulted in more mice surviving (p = .0359). Moreover, the villi in the mucosal of group-CS layer fell off, goblet cells missed, and crypts disappeared. The mucosal layer and submucosa were clearly separated. The morphology of intestinal tissue of the CFS and FS group was improved. After FMT, the changes of the GM were observed.

CONCLUSIONS

The GM may be involved in the epilepsy induced by cefoperazone/sulbactam in CRF mice. FMT can delay the onset of epilepsy in CRF mice induced by cefoperazone/sulbactam, and the earlier the intervention, the better the effect.

Yi-Shen-Hua-Shi regulates intestinal microbiota dysbiosis and protects against proteinuria in patients with chronic kidney disease: a randomized controlled study

CONTEXT

Yi-Shen-Hua-Shi (YSHS) is a traditional Chinese medicine that treats chronic kidney disease (CKD). However, its efficacy in reducing proteinuria and underlying mechanisms is unknown.

OBJECTIVE

This single-center randomized controlled trial explored whether YSHS could improve proteinuria and modulate the gut microbiota.

MATERIALS AND METHODS

120 CKD patients were enrolled and randomized to receive the renin-angiotensin-aldosterone system (RAAS) inhibitor plus YSHS (n = 56) or RAAS inhibitor (n = 47) alone for 4 months, and 103 patients completed the study. We collected baseline and follow-up fecal samples and clinical outcomes from participants. Total bacterial DNA was extracted, and the fecal microbiome was analyzed using bioinformatics.

RESULTS

Patients in the intervention group had a significantly higher decrease in 24-h proteinuria. After 4 months of the YSHS intervention, the relative abundance of bacteria that have beneficial effects on the body, such as Faecalibacterium, Lachnospiraceae, Lachnoclostridium, and Sutterella increased significantly, while pathogenic bacteria such as the Eggerthella and Clostridium innocuum group decreased. However, we could not find these changes in the control group. Redundancy analysis showed that the decline in 24-h proteinuria during follow-up was significantly correlated with various taxa of gut bacteria, such as Lachnospiraceae and the Lachnoclostridium genus in the YSHS group. KEGG analysis also showed the potential role of YSHS in regulating glycan, lipid, and vitamin metabolism.

DISCUSSION AND CONCLUSION

The YSHS granule reduced proteinuria associated with mitigating intestinal microbiota dysbiosis in CKD patients. The definite mechanisms of YSHS to improve proteinuria need to be further explored.

TRIAL REGISTRATION

ChiCTR2300076136, retrospectively registered.

An atlas on risk factors for gastrointestinal cancers: A systematic review of Mendelian randomization studies

OBJECTIVE

Gastrointestinal cancers are one of the most frequent cancer types and seriously threaten human life and health. Recent studies attribute the occurrence of gastrointestinal cancers to both genetic and environmental factors, yet the intrinsic etiology remains unclear. Mendelian randomization is a powerful well-established statistical method that is based on genome-wide association study (GWAS) to evaluate the causal relationship between exposures and outcomes. In the present study, we aimed to conduct a systematic review of Mendelian randomization studies investigating any causal risk factors for gastrointestinal cancers.

METHODS

We systematically searched Mendelian randomization studies that addressed the associations of genetically predicted exposures with five main gastrointestinal cancers from September 2014 to March 2024, as well as testing the research quality and validity.

RESULTS

Our findings suggested robust and consistent causal effects of body mass index (BMI), basal metabolic rate, fatty acids, total cholesterol, total bilirubin, insulin like growth factor-1, eosinophil counts, interleukin 2, alcohol consumption, coffee consumption, apolipoprotein B on colorectal cancer risks, BMI, waist circumference, low-density lipoprotein (LDL), total testosterone, smoking on gastric cancer risks, BMI, fasting insulin, LDL, waist circumference, visceral adipose tissue (VAT), immune cells, type 2 diabetes mellitus (T2DM) on pancreatic cancer risks, waist circumference, smoking, T2DM on esophageal adenocarcinoma risks, and VAT, ferritin, transferrin, alcohol consumption, hepatitis B virus infection, rheumatoid arthritis on liver cancer risks, respectively.

CONCLUSION

Larger, well-designed Mendelian randomization studies are practical in determining the causal status of risk factors for diseases.

Oral Astragalus polysaccharide alleviates adenine-induced kidney injury by regulating gut microbiota-short-chain fatty acids-kidney G protein-coupled receptors axis

Chronic kidney disease (CKD) can cause gut microbiota dysbiosis and decreasing production of short-chain fatty acids (SCFAs), which aggravate the injury of kidney. It has been found that a variety of Chinese medicine polysaccharides can regulate gut microbiota, especially probiotics, and have beneficial effects on human health. Astragalus polysaccharide (APS) is a major component of Astragalus aceus. The aim of this study was to investigate whether APS can regulate gut microbiota-SCFAs to slow the progression of CKD. Adenine-induced CKD mice (Ade) were established and APS was treated. The renal protection of APS on CKD mice was evaluated by renal function and pathological staining of renal tissues. Feces samples were collected for 16SrRNA sequence and LC-MS/MS analysis. Kidney G protein-coupled receptor (GPR) levels were also detected in renal tissue. APS supplementation can reduce serum creatinine and urea nitrogen levels in mice model (Ade) and attenuate renal tubular interstitial injury and renal fibrosis. Further application of 16SrRNA sequencing showed that the abundance of SCFA producing bacteria, such as Kineothrix, Faecalibaculum, Akkermansia, Lactobacillus, and Roseburia, was upregulated after APS treatment. Fecal LC-MS/MS detection showed that the levels of acetate, propionate and butyrate in Ade mice increased after APS supplementation. The detection of renal GPRs showed that APS supplementing could significantly increase the levels of renal GPR41 and GPR43, and also partially increase the levels of GPR109a in Ade mice. Our research confirms that APS supplementation can upregulate the abundance of SCFA producing bacteria and increase SCFA levels to attenuate renal tubular interstitial injury and fibrosis via GPRs.

Resveratrol Butyrate Esters Reduce Hypertension in a Juvenile Rat Model of Chronic Kidney Disease Exacerbated by Microplastics

BACKGROUND

Resveratrol is recognized as a promising nutraceutical with antihypertensive and prebiotic properties; however, its bioavailability in vivo is limited. To enhance its bioactivity, we developed resveratrol butyrate esters (RBEs). This study investigates whether RBEs can mitigate hypertension induced by chronic kidney disease (CKD) and exacerbated by microplastics (MPs) exposure in juvenile rats.

METHODS

Three-week-old male Sprague Dawley rats were fed either regular chow or 0.5% adenine chow for three weeks. The adenine-fed CKD rats (N = 8 per group) received either 5 μM MPs (10 mg/L) or MPs combined with RBE (25 mg/L) in their drinking water from weeks 3 to 9.

RESULTS

Our results indicate that MP exposure worsened CKD-induced hypertension, while RBE treatment resulted in a reduction in systolic BP by 15 mmHg (155 ± 2 mmHg vs. 140 ± 1 mmHg, p < 0.05). The combined exposure to adenine and MPs was associated with nitric oxide (NO) deficiency, which RBE treatment alleviated. Additionally, our findings revealed that RBE modulated both the classical and nonclassical renin-angiotensin system (RAS), contributing to its protective effects. We also observed changes in gut microbiota composition, increased butyric acid levels, and elevated renal GPR41 expression associated with RBE treatment.

CONCLUSIONS

In conclusion, in this juvenile rat model of combined CKD and MP exposure, RBE demonstrates antihypertensive effects by modulating NO levels, the RAS, gut microbiota, and their metabolites.

Taurine Supplementation Alleviates Blood Pressure via Gut-Brain Communication in Spontaneously Hypertensive Rats

OBJECTS

Taurine exhibits protective effects in the context of cardiovascular pathophysiology. A range of evidence suggests that hypertension activates inflammatory responses and oxidative stress in the paraventricular nucleus (PVN), elevating the arterial tone and sympathetic activity, while it induces gut-brain axis dysfunction in the context of hypertension. However, the mechanism underlying taurine's anti-hypertensive effects via the gut-brain axis remains unclear.

METHOD

Male spontaneously hypertensive rats (SHRs) were administered 3% taurine in their drinking water for eight weeks, with their arterial pressure measured weekly. Molecular techniques were employed to investigate taurine's effects on the hypertensive gut and PVN. Additionally, 16S rRNA gene sequencing was used to analyze the gut microbiota composition, and untargeted metabolomics was applied to assess the fecal metabolites following taurine supplementation.

RESULTS

Taurine supplementation not only reduced the blood pressure, sympathetic activity, and inflammatory and oxidative stress in the PVN but also improved the cardiac pathology and microbiota composition while alleviating gut inflammation in hypertensive rats. The untargeted metabolite analysis indicated that the primary effect of the taurine intervention in SHRs was exerted on tryptophan metabolism. The levels of serum metabolites such as kynurenine, L-tryptophan, serotonin (5-HT), and 5-hydroxyindole-3-acetic acid (5-HIAA) were altered in hypertensive rats following taurine treatment.

CONCLUSIONS

Taurine supplementation restored the microbiota balance, strengthened the mucosal barrier, reduced intestinal inflammation, and stimulated tryptophan metabolism. The metabolites derived from the gut microbiota likely crossed the brain barrier and reached the paraventricular nucleus, thereby reducing the inflammatory responses and oxidative stress in the PVN via gut-brain communication, leading to decreased sympathetic nerve activity and blood pressure in the studied hypertensive rats.

Gut Microbiota and Gut-Brain Axis in Hypertension: Implications for Kidney and Cardiovascular Health-A Narrative Review

INTRODUCTION

Arterial hypertension is a major contributor to a wide range of health complications, with cardiac hypertrophy and chronic kidney disease being among the most prevalent. Consequently, novel strategies for the treatment and prevention of hypertension are actively being explored. Recent research has highlighted a potential link between hypertension and the gut-brain axis. A bidirectional communication between the microbiota and the brain via the vagus nerve, enteric nervous system, hypothalamus-pituitary-adrenal axis, secreted short-chain fatty acids, and neurotransmitter metabolism.

MATERIALS AND METHODS

A comprehensive literature search was conducted using databases such as PubMed to identify studies exploring the relationship between gut microbiota and hypertension, along with the effects of dietary interventions and probiotics on blood pressure regulation.

DISCUSSION

Studies in both animal models and human subjects have demonstrated a strong correlation between alterations in gut microbiota composition and the development of hypertension. By influencing blood pressure, the gut microbiota can potentially affect the progression of cardiovascular and kidney disorders. Modulating gut microbiota through dietary interventions and probiotics has shown promise in regulating blood pressure and reducing systemic inflammation, offering a novel approach to managing hypertension. Diets such as the Mediterranean diet, which is rich in polyphenols and omega-3 fatty acids and low in sodium, promote the growth of beneficial gut bacteria that support cardiovascular health. Additionally, probiotics have been found to enhance gut barrier function, reduce inflammation, and modulate the Renin-Angiotensin System, all of which contribute to lowering blood pressure.

CONCLUSIONS

Further research is needed to determine the mechanisms of action of the microbiota in hypertension. The aim of this study was to evaluate the influence of gut microbiota on blood pressure regulation and the progression of hypertension-related complications, such as cardiovascular and kidney disorders.

Microplastics and human health: unveiling the gut microbiome disruption and chronic disease risks

Microplastics (MPs), defined as plastic particles smaller than 5 mm, are increasingly recognized as environmental contaminants with potential health risks. These emerge as breakdown products of larger plastics and are omnipresent in marine, freshwater, and terrestrial ecosystems. They are primarily composed of polymers such as polyethylene, polypropylene, polystyrene, and additives that enhance their performance. MPs also adsorb harmful environmental chemicals like persistent organic pollutants and heavy metals, posing risks to human and environmental health. Human exposure to MPs occurs mainly through ingestion and inhalation, with MPs detected in food products, water, and even the air. MPs have been shown to accumulate in the gastrointestinal tract, disrupting the gut microbiome, and causing dysbiosis-a harmful imbalance between beneficial and harmful bacteria. This disruption has been linked to various health issues, including gastrointestinal disorders, systemic inflammation, and chronic diseases. Furthermore, the gut-brain axis may be affected, with potential neuroinflammatory consequences. As research continues to unravel the health impacts of MP exposure, understanding the mechanisms of accumulation and the broader implications on human health is crucial. This review highlights the effects of MPs on human health, emphasizing their impact on the gut microbiome. We discuss the potential connections between MP exposure and cardiometabolic and inflammatory diseases, and disorders related to the Gut-Brain Axis. By synthesizing the latest research, this work sheds light on the silent yet pervasive threat posed by MPs and underscores the importance of further studies to understand their health impacts fully.

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.

GOS enhances BDNF-mediated mammary gland development in pubertal mice via the gut-brain axis

The "gut-brain axis" is involved in many physiological processes. However, its role in regulating mammary gland (MG) development remains unknown. In this study, we established the mice model of bilateral subdiaphragmatic vagotomy (Vago) to clarify the effects of "gut-brain axis" on MG development in pubertal mice. The results showed that Vago reduced the ratio of Lactobacillus and Bifidobacterium, neuronal excitability in the nucleus of solitary tract (NTS), and synthesis and secretion of BDNF, thereby slowing MG development. Transplanting the gut microbiota of Vago mice to recipient mice replicated these effects, and transplanting the gut microbiota of Control mice to Vago mice did not alleviate these effects. Galacto-Oligosaccharide (GOS), which up-regulates the ratio of Lactobacillus and Bifidobacterium, supplementation elevated NTS neuron excitability, synthesis and secretion of BDNF, and MG development, but Vago reversed these benefits. In conclusion, GOS enhances BDNF-mediated mammary gland development in pubertal mice via the "gut-brain axis".

Utilization of diverse probiotics to create human health promoting fatty acids: A review

Many probiotics produce functional lipids with health-promoting properties, such as short-chain fatty acids, linoleic acid and omega-3 fatty acids. They have been shown to maintain gut health, strengthen the intestinal barrier, and have anti-inflammatory and antioxidant effects. In this article, we provide an up-to-date review of the various functional lipids produced by probiotics. These probiotics can be incorporated into foods, supplements, or pharmaceuticals to produce these functional lipids in the human colon, or they can be used in industrial biotechnology processes to generate functional lipids, which are then isolated and used as ingredients. We then highlight the different physiological functions for which they may be beneficial to human health, in addition to discussing some of the challenges of incorporating probiotics into commercial products and some potential solutions to address these challenges. Finally, we highlight the importance of testing the efficacy and safety of the new generation of probiotic-enhanced products, as well as the great potential for the marketization of related products.

Polysaccharide isolated from Dioscorea septemloba improves hyperuricemia and alleviates renal fibrosis through gut-kidney axis in mice

Hyperuricemia (HUA) is a common metabolic disorder that often accompanies kidney diseases such as tubule damage and renal interstitial fibrosis. The preventive and therapeutic effects of Dioscorea septemloba, an anti-HUA herb, polysaccharide of which was considered as the main active ingredient on HUA, need to be explored. The major polysaccharide component, BXP, was purified from Dioscorea septemloba, with an average molecular weight of 10.432 kDa. Structural analysis inferred that BXP backbone was composed of t-β-D-Glcp-(1→4)-α-D-Glcp-(1 → 4)-α-D-Glcp-(1 → 4, 3)-β-D-Glcp-(1 → , along with the side chain of →1)-α-D-Glcp-(6, 4 → 3, 4)-β-D-Glcp-(1→. The HUA mouse model was further established to clarify the underlying effect of BXP on HUA alleviation. As results shown, BXP decreased serum uric acid by inhibiting XOD and regulating urate transporter expression (GLUT9, OAT3, OAT1, URAT1 and ABCG2) in HUA mice, as well as relieving kidney and liver damage. Moreover, results of microbiome and metabolomics indicated that BXP improved the abundance of gut bacteria and reversed the Lipids-related metabolism disorder caused by HUA. This study indicated that BXP had potential to alleviate HUA and kidney disease through the gut-kidney axis in mice.

Functions and mechanisms of nonstarch polysaccharides in monogastric animal production

As natural active ingredients, polysaccharides are a class of biological macromolecules that are ubiquitous in living organisms and have antibacterial, antioxidant, antitumor and intestinal flora-regulating functions. Nonstarch polysaccharides (NSPs) are an important class of polysaccharides that include both soluble and insoluble nonstarch polysaccharides. As green feed additives, NSPs play important roles in promoting immunity and disease resistance in the body, regulating the intestinal microbial balance and improving the quality of animal products. NSPs regulate cell signal transduction mainly via interactions between short-chain fatty acids and G protein-coupled receptors and inhibiting the histone deacetylation pathway to protect the intestinal barrier in animals. In this paper, the composition, physiological functions, and molecular mechanisms of the gut protective effects of NSPs are reviewed to provide a reference for the application of NSPs in monogastric animal production.

The Role of the Microbiome and of Radiotherapy-Derived Metabolites in Breast Cancer

The gut microbiome has emerged as a crucial player in modulating cancer therapies, including radiotherapy. In the case of breast cancer, the interplay between the microbiome and radiotherapy-derived metabolites may enhance therapeutic outcomes and minimize adverse effects. In this review, we explore the bidirectional relationship between the gut microbiome and breast cancer. We explain how gut microbiome composition influences cancer progression and treatment response, and how breast cancer and its treatments influence microbiome composition. A dual role for radiotherapy-derived metabolites is explored in this article, highlighting both their therapeutic benefits and potential hazards. By integrating genomics, metabolomics, and bioinformatics tools, we present a comprehensive overview of these interactions. The study provides real-world insight through case studies and clinical trials, while therapeutic innovations such as probiotics, and dietary interventions are examined for their potential to modulate the microbiome and enhance treatment effectiveness. Moreover, ethical considerations and patient perspectives are discussed, ensuring a comprehensive understanding of the subject. Towards revolutionizing treatment strategies and improving patient outcomes, the review concludes with future research directions. It also envisions integrating microbiome and metabolite research into personalized breast cancer therapy.

Mizhuo Guanchangye enema delays the decline of renal function in rats with chronic kidney disease by intervening in the TLR4/MyD88/NF-κB pathway

Background

Chronic kidney disease (CKD) is a prevalent chronic condition that poses a significant threat to human health. There is a close connection between the gut and kidneys, jointly influencing the onset and progression of CKD through the "gut-kidney axis." Traditional Chinese medicine has shown potential in CKD treatment, but the specific mechanisms require further investigation.

Objectives

This study aims to explore the protective effects of Mizhuo Enema (MZGCY) on kidney function in CKD rats by regulating the TLR4/MyD88/NF-κB signaling pathway.

Methods

The researcher employed a CKD rat model, which was divided into four groups: Control, Model, half-dose Mizhuo Guanchangye (1/2 MZGCY), and full-dose Mizhuo Guanchangye (MZGCY). Post enema administration, assessments were conducted on kidney function indicators, which included blood urea nitrogen (BUN), serum creatinine (SCR), and 24-h urinary protein. Additionally, measurements were taken for intestinal toxic substances such as indoxyl sulfate (IS) and lipopolysaccharide (LPS), as well as inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Examinations of pathological changes in both the intestines and kidneys were also performed. During this process, immunofluorescence was utilized to detect the expression levels of proteins toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), and nuclear factor kappa B (NF-κB) in the intestinal tissues.

Results

It was found that after enema treatment, the BUN, SCR, and 24-h urinary protein levels in the MZGCY and 1/2 MZGCY groups significantly decreased, indicating notable improvement in kidney function. Compared to the model group, the IS, LPS, IL-6, and TNF-α levels in the MZGCY and 1/2 MZGCY groups were significantly reduced. Immunofluorescence showed a marked decrease in the expression of TLR4, MyD88, and NF-κB proteins in the intestines of the MZGCY group.

Conclusion

MZGCY significantly reduces the levels of intestinal toxins and inflammatory factors in the serum of CKD rats by interfering with the TLR4/MyD88/NF-κB signaling pathway, thereby improving intestinal and renal pathological changes and delaying CKD progression. This study demonstrates that MZGCY has significant renal protective effects, providing a new potential approach for CKD treatment.

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.