Chronic kidney disease and gut microbiota

Impact of gut microbiota in chronic kidney disease: natural polyphenols as beneficial regulators

Chronic kidney disease (CKD) poses a severe health risk with high morbidity and mortality, profoundly affecting patient quality of life and survival. Despite advancements in research, the pathophysiology of CKD remains incompletely understood. Growing evidence links CKD with shifts in gut microbiota function and composition. Natural compounds, particularly polyphenols, have shown promise in CKD treatment due to their antioxidant and anti-inflammatory properties and their ability to modulate gut microbiota. This review discusses recent progress in uncovering the connections between gut microbiota and CKD, including microbiota changes across different kidney diseases. We also examine metabolite alterations,such as trimethylamine-N-oxide, tryptophan derivatives, branched-chain amino acids, short-chain fatty acids, and bile acids,which contribute to CKD progression. Further, we outline the mechanisms through which polyphenols exert therapeutic effects on CKD, focusing on signaling pathways like nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK), mammalian target of rapamycin (mTOR), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), phosphatidylin-ositol-3-kinase (PI3K)/protein kinase B (Akt), and toll like receptors (TLR), as well as their impact on gut microbiota. Lastly, we consider how dietary polyphenols could be harnessed as bioactive drugs to slow CKD progression. Future research should prioritize multi-omics approaches to identify patients who would benefit from polyphenolic interventions, enabling personalized treatment strategies to enhance therapeutic efficacy.

Characterization of gut dysbiosis and intestinal barrier dysfunction in patients with metabolic dysfunction-associated steatotic liver disease and chronic kidney disease: a comparative study

The mechanistic role of gut microbiota in metabolic dysfunction-associated steatotic liver disease (MASLD) and chronic kidney disease (CKD) is increasingly recognized. Despite their close association, comparative data regarding gut dysbiosis in these disorders are limited. This study included 22 healthy controls and 180 patients (90 MASLD, 60 CKD, and 30 both diseases with sex- and age-matched). Fecal bacterial 16 S ribosomal RNA sequencing and butyryl-CoA: acetate CoA transferase (BCoAT) gene expression were analyzed. Plasma intestinal fatty acid binding protein (I-FABP), representing intestinal barrier dysfunction, was assessed using the ELISA method. Our data showed that alpha and beta diversities of gut microbiota differed between MASLD and healthy controls. However, only beta diversities were different between CKD and healthy individuals. The MASLD and CKD groups displayed fewer SCFA-producing genera, particularly Bifidobacterium, than healthy controls. Fecal BCoAT levels were inversely correlated with eGFR and I-FABP levels. Patients with CKD had significantly enriched pathogenic bacteria, reduced BCoAT, and increased I-FABP levels versus MASLD. Combining significant bacterial genera discriminated MASLD from CKD with high diagnostic accuracy (AUC of 0.90). Among patients with both diseases, gut microbial alterations showed mixed characteristics of MASLD and CKD. These data highlighted the shared and distinct gut dysbiosis and related biomarkers, which could provide a better understanding of MASLD and CKD pathogenesis.

Analysis of research trends and hotspots in the primary treatment of end-stage renal disease

BACKGROUND

There is a lack of bibliometric analysis in research regarding primary therapy for end-stage renal disease (ESRD). This study aims to analyze the literature on ESRD therapy published over the past decade to understand current conditions and study trends for future research.

METHODS

Data were collected from the Web of Science Core Collection (WOSCC) database. Tools like CiteSpace 6.2.R4, 6.1.R6, VOSviewer 1.6.18, and Bibliometrix R4.1.1 were used to reveal research trends and hotspots. In addition, KEGG/GO analysis examined the probable functionalities of genes implicated in ESRD therapy to guide future research.

RESULTS

The bibliometric analysis presented in this paper indicates that the number of publications has remained relatively stable since 2013. The level of international collaboration is notably high, with the United States serving as the dominant research hub in this field. The University of California system is the most prolific institution, and Transplantation Proceedings is the most frequently published journal in this area. Kalantar-Zadeh, Kamyar is recognized as the most published and cited author. Keywords such as "secondary hyperparathyroidism," "uremic toxins," "cyclosporine," "mycophenolate mofetil," and "biomarkers" have seen a surge in interest recently, reflecting emerging research trends. Furthermore, inflammation and stem cell research have been identified as promising new therapeutic avenues for ESRD.

CONCLUSION

This study identifies major areas, frontiers, and trends in research on primary treatments for ESRD, providing significant implications for future research.

Impact of Gut Microbiome Modulation on Uremic Toxin Reduction in Chronic Kidney Disease: A Systematic Review and Network Meta-Analysis

Background/Objectives: Chronic kidney disease is associated with increased intestinal barrier permeability, leading to heightened inflammation and oxidative stress. These changes contribute to complications such as cardiovascular disease, anemia, altered mineral metabolism, and CKD progression. Interventions using prebiotics, probiotics, and synbiotics may mitigate dysbiosis and improve intestinal barrier function, Under this premise, the objective of this network meta-analysis was to evaluate the effect of probiotics, prebiotics, and synbiotics in reducing uremic toxins produced by the gut microbiota in CKD patients. Methods: A systematic review and network meta-analysis of randomized clinical trials (RCTs) was performed in the following databases: Web of Science, Scopus, the Cochrane Register of Controlled Trials, and PubMed published between 2019 and 2023. The analysis focused on the use of prebiotics, probiotics, and synbiotics in CKD patients at stages 3 to 5, as per KDIGO guidelines, and their association with reductions in uremic toxins such as Indoxyl Sulfate, p-Cresyl Sulfate, urea, and creatinine. The risk of bias was assessed using the Cochrane risk of bias tool (RoB 2), with evaluations conducted independently by two reviewers, and a third consulted for disagreements. The study follows the PRISMA statement. Results: The studies included 331 patients, primarily male, across CKD stages 3a to 5. The interventions positively impacted the gut microbiota composition, leading to reductions in free and total p-Cresyl Sulfate (SUCRA: 72.6% and 66.2, respectively) and indoxyl sulfate (SUCRA: 88.5% and 83.1%). Conclusions: The findings suggest that modulating the gut microbiota through these interventions can effectively reduce specific uremic toxins. However, further trials are necessary to better understand microbiota modulation and its impact on intestinal bacterial composition (PROSPERO number: CRD42023438901).

Gut microbiota-derived metabolites: Potential targets for cardiorenal syndrome

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

Unlocking the secrets of the human gut microbiota: Comprehensive review on its role in different diseases

The human gut microbiota, a complex and diverse community of microorganisms, plays a crucial role in maintaining overall health by influencing various physiological processes, including digestion, immune function, and disease susceptibility. The balance between beneficial and harmful bacteria is essential for health, with dysbiosis - disruption of this balance - linked to numerous conditions such as metabolic disorders, autoimmune diseases, and cancers. This review highlights key genera such as Enterococcus, Ruminococcus, Bacteroides, Bifidobacterium, Escherichia coli, Akkermansia muciniphila, Firmicutes (including Clostridium and Lactobacillus), and Roseburia due to their well-established roles in immune regulation and metabolic processes, but other bacteria, including Clostridioides difficile, Salmonella, Helicobacter pylori, and Fusobacterium nucleatum, are also implicated in dysbiosis and various diseases. Pathogenic bacteria, including Escherichia coli and Bacteroides fragilis, contribute to inflammation and cancer progression by disrupting immune responses and damaging tissues. The potential for microbiota-based therapies, such as probiotics, prebiotics, fecal microbiota transplantation, and dietary interventions, to improve health outcomes is examined. Future research directions in the integration of multi-omics, the impact of diet and lifestyle on microbiota composition, and advancing microbiota engineering techniques are also discussed. Understanding the gut microbiota's role in health and disease is essential for formulating personalized, efficacious treatments and preventive strategies, thereby enhancing health outcomes and progressing microbiome research.

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.

Recent status and trends of innate immunity and the gut-kidney aixs in IgAN: A systematic review and bibliometric analysis

BACKGROUND

There is a significant global demand for precise diagnosis and effective treatment of IgA nephropathy (IgAN), with innate immunity, particularly the complement system, exerting a profound influence on its pathogenesis. Additionally, the gut-kidney axis pathway is vital in the emergence and development of IgAN.

METHODS

We conducted a comprehensive search in the Web of Science database, spanning from January 1, 2000 to December 18, 2023. The gathered literature underwent a visual examination through CiteSpace, VOSviewer, and Scimago Graphica to delve into authors, nations, organizations, key terms, and other pertinent elements.

RESULT

Between 2000 and 2023, a total of 720 publications were identified, out of which 436 publications underwent screening for highly relevant literature analysis. The average annual number of articles focusing on IgAN, innate immunity, and the gut-kidney axis is approximately 31, with an upward trend observed. In terms of research impact encompassing publication count and authorship, the United States emerged as the leading contributor. Prominent keywords included "complement", "activation", "microbe", "gut-kidney axis", "C4d deposition", "alternative pathway" and "B cells" along with other prospective hot topics.

CONCLUSION

The correlation between IgAN and innate immunity is a focal point in current scientific research. Recent literature underscores the significance of the gut-kidney axis, where intestinal microorganisms and metabolites may influence IgAN. The complement system, a key component of innate immunity, also has a crucial function.Advancements in prevention, diagnosis, and treatment hinge on unraveling this intricate relationship.

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

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

Gut microbiota and Alzheimer's disease: Exploring natural product intervention and the Gut-Brain axis for therapeutic strategies

Numerous studies conducted over the last ten years have shown a strong correlation between the gut microbiota and the onset and progression of Alzheimer's disease (AD). However, the exact underlying mechanism is still unknown. An ongoing communication mechanism linking the gut and the brain is highlighted by the term "microbiota-gut-brain axis," which was originally coined the "gut-brain axis." Key metabolic, endocrine, neurological, and immunological mechanisms are involved in the microbiota‒gut‒brain axis and are essential for preserving brain homeostasis. Thus, the main emphasis of this review is how the gut microbiota contributes to the development of AD and how various natural products intervene in this disease. The first part of the review provides an outline of various pathways and relationships between the brain and gut microbiota, and the second part provides various mechanisms involved in the gut microbiota and AD. Finally, this review provides knowledge about natural products and their effectiveness in treating gut microbiota-induced AD. AD may be treated in the future by altering the gut microbiota with a customized diet, probiotics/prebiotics, plant products, and natural products. This entails altering the microbiological partners and products (such as amyloid protein) that these partners generate.

Nutritional assessment and medical dietary therapy for management of obesity in patients with non-dialysis chronic kidney disease: a practical guide for endocrinologist, nutritionists and nephrologists. A consensus statement from the Italian society of endocrinology (SIE), working group of the club nutrition-hormones and metabolism; the Italian society of nutraceuticals (SINut), club ketodiets and nutraceuticals "KetoNut-SINut"; and the Italian society of nephrology (SIN)

PURPOSE

Chronic kidney disease (CKD) is a serious health concern with an estimated prevalence of about 13.4% worldwide. It is cause and consequence of various comorbidities, including cardiovascular diseases. In parallel, common pathological conditions closely related to ageing and unhealthy dietary habits increase the risk of CKD development and progression, including type 2 diabetes and obesity. Among these, obesity is either independent risk factor for new onset kidney disease or accelerates the rate of decline of kidney function by multiple mechanisms. Therefore, the role of diets aimed at attaining weight loss in patients with obesity is clearly essential to prevent CKD as to slow disease progression. Various dietary approaches have been licensed for the medical dietary therapy in CKD, including low-protein diet and Mediterranean diet. Interestingly, emerging evidence also support the use of low-carbohydrate/ketogenic diet (LCD/KD) in these patients. More specifically, LCD/KDs may efficiently promote weight loss, improve metabolic parameters, and reduce inflammation and oxidative stress, resulting in a dietary strategy that act globally in managing collateral conditions that are directly and indirectly related to the kidney function.

CONCLUSION

This consensus statement from the Italian Society of Endocrinology (SIE), working group of the Club Nutrition - Hormones and Metabolism; the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut"; and the Italian Society of Nephrology (SIN) is intended to be a guide for Endocrinologist, Nutritionists and Nephrologist who deal with the management of patients with obesity with non-dialysis CKD providing a practical guidance on assessing nutritional status and prescribing the optimal diet in order to best manage obesity to prevent CKD and its progression to dialysis.

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.

Gut Microbiota in Patients Receiving Dialysis: A Review

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

Gut microbiota dynamics and association with chronic kidney disease: A longitudinal study within the PREDIMED-Plus trial

AIMS

Chronic kidney disease (CKD) represents a global health concern, disproportionately affecting the elderly with heightened cardiovascular risk. The emerging focus on the gut microbiota's role in CKD pathophysiology represents a pivotal area in nephrology; however, the evidence on this topic is limited. This observational prospective study, in the framework of the PREDIMED-Plus trial, investigates associations between gut microbiota composition and the 1-year trajectory of CKD in 343 participants aged 55-75 years with high cardiovascular risk.

MATERIALS AND METHODS

Kidney function was assessed at baseline and at 1-year of follow-up through the estimated glomerular filtration rate based on cystatin C (eGFR-CysC) and CKD defined by eGFR-CysC <60 mL/min/1.73 m2. Participants were grouped based on their 1-year CKD trajectory: Group 1 maintained normal status or improved from CKD to normal, while Group 2 maintained CKD or worsened from normal to CKD. Fecal microbiota composition was assessed through 16S sequencing.

KEY FINDINGS

We observed differences in gut microbiota composition between CKD trajectory groups. Notably, the baseline relative abundance of Lachnoclostridium and Lachnospira, both butyrate-producing genera, was lower in participants maintaining or progressing to CKD. Longitudinally, a decrease in Lachnospira abundance was associated with CKD progression. The improved Chao1 index after 1-year follow-up suggests a link between enhanced microbial richness and stable/better kidney function.

SIGNIFICANCE

The findings underscore the potential of gut microbiota analysis in non-invasively monitoring CKD, especially in older populations, and hint at future interventions targeting gut microbiota to manage CKD progression. Further research is needed for causal relationships and generalizability.

Metagenomics and metaproteomics alterations are associated with kidney disease in opisthorchiasis hamsters fed a high-fat and high-fructose diet

BACKGROUND

Opisthorchis viverrini (O. viverrini, Ov) infection and consumption of high-fat and high-fructose (HFF) diet exacerbate liver and kidney disease. Here, we investigated the effects of a combination of O. viverrini infection and HFF diet on kidney pathology via changes in the gut microbiome and host proteome in hamsters.

METHODOLOGY/PRINCIPAL FINDINGS

Twenty animals were divided into four groups; 1) fed a normal diet not infected with O. viverrini (normal group), 2) fed an HFF diet and not infected with O. viverrini (HFF), 3) fed a normal diet and infected with O. viverrini (Ov), and 4) fed an HFF diet and infected with O. viverrini (HFFOv). DNA was extracted from fecal samples and the V3-V4 region of the bacterial 16S rRNA gene sequenced on an Illumina MiSeq sequencing platform. In addition, LC/MS-MS analysis was done. Histopathological studies and biochemical assays were also conducted. The results indicated that the HFFOv group exhibited the most severe kidney injury, manifested as elevated KIM-1 expression and accumulation of fibrosis in kidney tissue. The microbiome of the HFFOv group was more diverse than in the HFF group: there were increased numbers of Ruminococcaceae, Lachnospiraceae, Desulfovibrionaceae and Akkermansiaceae, but fewer Eggerthellaceae. In total, 243 host proteins were identified across all groups. Analysis using STITCH predicted that host proteome changes may lead to leaking of the gut, allowing molecules such as soluble CD14 and p-cresol to pass through to promote kidney disease. In addition, differential expression of TGF-beta-activated kinase 1 and MAP3K7-binding protein 2 (Tab2, involving renal inflammation and injury) are predicted to be associated with kidney disease.

CONCLUSIONS/SIGNIFICANCE

The combination of HFF diet and O. viverrini infection may promote kidney injury through alterations in the gut microbiome and host proteome. This knowledge may suggest an effective strategy to prevent kidney disease beyond the early stages.

Revitalizing the Gut Microbiome in Chronic Kidney Disease: A Comprehensive Exploration of the Therapeutic Potential of Physical Activity

Both physical inactivity and disruptions in the gut microbiome appear to be prevalent in patients with chronic kidney disease (CKD). Engaging in physical activity could present a novel nonpharmacological strategy for enhancing the gut microbiome and mitigating the adverse effects associated with microbial dysbiosis in individuals with CKD. This narrative review explores the underlying mechanisms through which physical activity may favorably modulate microbial health, either through direct impact on the gut or through interorgan crosstalk. Also, the development of microbial dysbiosis and its interplay with physical inactivity in patients with CKD are discussed. Mechanisms and interventions through which physical activity may restore gut homeostasis in individuals with CKD are explored.

Lipid metabolism disorder in diabetic kidney disease

Diabetic kidney disease (DKD), a significant complication associated with diabetes mellitus, presents limited treatment options. The progression of DKD is marked by substantial lipid disturbances, including alterations in triglycerides, cholesterol, sphingolipids, phospholipids, lipid droplets, and bile acids (BAs). Altered lipid metabolism serves as a crucial pathogenic mechanism in DKD, potentially intertwined with cellular ferroptosis, lipophagy, lipid metabolism reprogramming, and immune modulation of gut microbiota (thus impacting the liver-kidney axis). The elucidation of these mechanisms opens new potential therapeutic pathways for DKD management. This research explores the link between lipid metabolism disruptions and DKD onset.

The Role of Probiotics in the Prevention of Clostridioides difficile Infection in Patients with Chronic Kidney Disease

In patients suffering from chronic kidney disease (CKD), substantial unfavourable alterations in the intestinal microbiota composition, i.e., dysbiosis, have been noted. The main causes of such dysbiosis among others are insufficient dietary fibre content in the diet, fluid restrictions, medications used, and physical activity limitation. One clinically important consequence of dysbiosis in CKD patients is high risk of Clostridioides difficile infection (CDI). In observational studies, it was found that CDI is more frequent in CKD patients than in the general population. This appears to be related to high hospitalization rate and more often antibiotic therapy use, leading up to the occurrence of dysbiosis. Therefore, the use of probiotics in CKD patients may avert changes in the intestinal microbiota, which is the major risk factor of CDI. The aim of this review paper is to summarize the actual knowledge concerning the use of probiotics in CDI prevention in CKD patients in the context of CDI prevention in the general population.

Gut Microbiota's Oxalate-Degrading Activity and Its Implications on Cardiovascular Health in Patients with Kidney Failure: A Pilot Prospective Study

Background and Objectives: The present study aims to investigate the association between gut microbiota's oxalate-degrading activity (ODA) and the risk of developing cardiovascular disease (CVD) over a three-year follow-up period in a cohort of patients undergoing kidney replacement therapy (KRT). Additionally, various factors were examined to gain insight into the potential mechanisms underlying the ODA-CVD link. Materials and Methods: A cohort of 32 KRT patients and 18 healthy volunteers was enrolled in this prospective observational pilot study. Total fecal ODA, routine clinical data, plasma oxalic acid (POx), serum indoxyl sulfate, lipid profile, oxidative stress, and proinflammatory markers were measured, and the patients were followed up for three years to assess CVD events. Results: The results revealed that patients with kidney failure exhibited significantly lower total fecal ODA levels compared to the healthy control group (p = 0.017), with a higher proportion showing negative ODA status (≤-1% per 0.01 g) (p = 0.01). Negative total fecal ODA status was associated with a significantly higher risk of CVD events during the three-year follow-up period (HR = 4.1, 95% CI 1.4-16.3, p = 0.003), even after adjusting for potential confounders. Negative total fecal ODA status was significantly associated with elevated POx and indoxyl sulfate levels and linked to dyslipidemia, increased oxidative stress, and inflammation, which are critical contributors to CVD. Conclusions: The findings contribute novel insights into the relationship between gut microbiota's ODA and cardiovascular health in patients undergoing KRT, emphasizing the need for further research to elucidate underlying mechanisms and explore potential therapeutic implications of targeting gut microbiota's ODA in this vulnerable population.

An Overview of Chronic Kidney Disease Pathophysiology: The Impact of Gut Dysbiosis and Oral Disease

Chronic kidney disease (CKD) is a severe condition and a significant public health issue worldwide, carrying the burden of an increased risk of cardiovascular events and mortality. The traditional factors that promote the onset and progression of CKD are cardiometabolic risk factors like hypertension and diabetes, but non-traditional contributors are escalating. Moreover, gut dysbiosis, inflammation, and an impaired immune response are emerging as crucial mechanisms in the disease pathology. The gut microbiome and kidney disease exert a reciprocal influence commonly referred to as "the gut-kidney axis" through the induction of metabolic, immunological, and endocrine alterations. Periodontal diseases are strictly involved in the gut-kidney axis for their impact on the gut microbiota composition and for the metabolic and immunological alterations occurring in and reciprocally affecting both conditions. This review aims to provide an overview of the dynamic biological interconnections between oral health status, gut, and renal pathophysiology, spotlighting the dynamic oral-gut-kidney axis and raising whether periodontal diseases and gut microbiota can be disease modifiers in CKD. By doing so, we try to offer new insights into therapeutic strategies that may enhance the clinical trajectory of CKD patients, ultimately advancing our quest for improved patient outcomes and well-being.

Intestinal homeostasis in the gut-lung-kidney axis: a prospective therapeutic target in immune-related chronic kidney diseases

In recent years, the role of intestinal homeostasis in health has received increasing interest, significantly improving our understanding of the complex pathophysiological interactions of the gut with other organs. Microbiota dysbiosis, impaired intestinal barrier, and aberrant intestinal immunity appear to contribute to the pathogenesis of immune-related chronic kidney diseases (CKD). Meanwhile, the relationship between the pathological changes in the respiratory tract (e.g., infection, fibrosis, granuloma) and immune-related CKD cannot be ignored. The present review aimed to elucidate the new underlying mechanism of immune-related CKD. The lungs may affect kidney function through intestinal mediation. Communication is believed to exist between the gut and lung microbiota across long physiological distances. Following the inhalation of various pathogenic factors (e.g., particulate matter 2.5 mum or less in diameter, pathogen) in the air through the mouth and nose, considering the anatomical connection between the nasopharynx and lungs, gut microbiome regulates oxidative stress and inflammatory states in the lungs and kidneys. Meanwhile, the intestine participates in the differentiation of T cells and promotes the migration of various immune cells to specific organs. This better explain the occurrence and progression of CKD caused by upper respiratory tract precursor infection and suggests the relationship between the lungs and kidney complications in some autoimmune diseases (e.g., anti-neutrophil cytoplasm antibodies -associated vasculitis, systemic lupus erythematosus). CKD can also affect the progression of lung diseases (e.g., acute respiratory distress syndrome and chronic obstructive pulmonary disease). We conclude that damage to the gut barrier appears to contribute to the development of immune-related CKD through gut-lung-kidney interplay, leading us to establish the gut-lung-kidney axis hypothesis. Further, we discuss possible therapeutic interventions and targets. For example, using prebiotics, probiotics, and laxatives (e.g., Rhubarb officinale) to regulate the gut ecology to alleviate oxidative stress, as well as improve the local immune system of the intestine and immune communication with the lungs and kidneys.

The Gut-Organ Axis within the Human Body: Gut Dysbiosis and the Role of Prebiotics

The human gut microbiota (GM) is a complex microbial ecosystem that colonises the gastrointestinal tract (GIT) and is comprised of bacteria, viruses, fungi, and protozoa. The GM has a symbiotic relationship with its host that is fundamental for body homeostasis. The GM is not limited to the scope of the GIT, but there are bidirectional interactions between the GM and other organs, highlighting the concept of the "gut-organ axis". Any deviation from the normal composition of the GM, termed "microbial dysbiosis", is implicated in the pathogenesis of various diseases. Only a few studies have demonstrated a relationship between GM modifications and disease phenotypes, and it is still unknown whether an altered GM contributes to a disease or simply reflects its status. Restoration of the GM with probiotics and prebiotics has been postulated, but evidence for the effects of prebiotics is limited. Prebiotics are substrates that are "selectively utilized by host microorganisms, conferring a health benefit". This study highlights the bidirectional relationship between the gut and vital human organs and demonstrates the relationship between GM dysbiosis and the emergence of certain representative diseases. Finally, this article focuses on the potential of prebiotics as a target therapy to manipulate the GM and presents the gaps in the literature and research.