Efficacy of probiotics on the modulation of gut microbiota in the treatment of diabetic nephropathy

Exploring the causal connection: insights into diabetic nephropathy and gut microbiota from whole-genome sequencing databases

Over recent years, the prevalence of diabetes has been on the rise, paralleling improvements in living standards. Diabetic nephropathy (DN), a prevalent complication of diabetes, has also exhibited a growing incidence. While some clinical studies and reviews have hinted at a link between diabetic nephropathy and gut microbiota (GM), the nature of this connection, specifically its causative nature, remains uncertain. Investigating the causal relationship between diabetic nephropathy and gut microbiota holds the promise of aiding in disease screening and identifying novel biomarkers. In this study, we employed a two-sample Mendelian randomization analysis. Our dataset encompassed 4,111 DN patients from the GWAS database, juxtaposed with 308,539 members forming a control group. The aim was to pinpoint specific categories within the vast spectrum of the 211 known gut microbiota types that may have a direct causal relationship with diabetic nephropathy. Rigorous measures, including extensive heterogeneity and sensitivity analyses, were implemented to mitigate the influence of confounding variables on our experimental outcomes. Ultimately, our comprehensive analysis revealed 15 distinct categories of gut microbiota that exhibit a causal association with diabetic nephropathy. In summary, the phyla Bacteroidota and Verrucomicrobiae, the families Peptostreptococcaceae and Veillonellaceae, the genus Akkermansia, and the species Catenibacterium, Lachnoclostridium, Parasutterella, along with the orders Bacteroidales and Verrucomicrobiales, and the class Bacteroidetes were identified as correlates of increased risk for DN. Conversely, the family Victivallaceae, the species Eubacterium coprostanoligenes, and the Clostridium sensu stricto 1 group were found to be associated with a protective effect against the development of DN.These findings not only provide valuable insights but also open up novel avenues for clinical research, offering fresh directions for potential treatments.

Traditional Chinese medicine improved diabetic kidney disease through targeting gut microbiota

CONTEXT

Diabetic kidney disease (DKD) affects nearly 40% of diabetic patients, often leading to end-stage renal disease that requires renal replacement therapies, such as dialysis and transplantation. The gut microbiota, an integral aspect of human evolution, plays a crucial role in this condition. Traditional Chinese medicine (TCM) has shown promising outcomes in ameliorating DKD by addressing the gut microbiota.

OBJECTIVE

This review elucidates the modifications in gut microbiota observed in DKD and explores the impact of TCM interventions on correcting microbial dysregulation.

METHODS

We searched relevant articles from databases including Web of Science, PubMed, ScienceDirect, Wiley, and Springer Nature. The following keywords were used: diabetic kidney disease, diabetic nephropathy, gut microbiota, natural product, TCM, Chinese herbal medicine, and Chinese medicinal herbs. Rigorous criteria were applied to identify high-quality studies on TCM interventions against DKD.

RESULTS

Dysregulation of the gut microbiota, including Lactobacillus, Streptococcus, and Clostridium, has been observed in individuals with DKD. Key indicators of microbial dysregulation include increased uremic solutes and decreased short-chain fatty acids. Various TCM therapies, such as formulas, tablets, granules, capsules, and decoctions, exhibit unique advantages in regulating the disordered microbiota to treat DKD.

CONCLUSION

This review highlights the importance of targeting the gut-kidney axis to regulate microbial disorders, their metabolites, and associated signaling pathways in DKD. The Qing-Re-Xiao-Zheng formula, the Shenyan Kangfu tablet, the Huangkui capsule, and the Bekhogainsam decoction are potential candidates to address the gut-kidney axis. TCM interventions offer a significant therapeutic approach by targeting microbial dysregulation in patients with DKD.

Causal relationship of gut microbiota with diabetic nephropathy: a Mendelian randomization analysis

Background

Patients with DN (diabetic nephropathy) show remarkable variations in their gut microbiota composition. However, to date, no study has shown whether a causal relationship exists between gut microbiota composition and DN.

Methods

Here, we performed a two-sample Mendelian randomization (MR) investigation for identifying causal associations of gut microbiota with DN. Gut microbiota genetic data were gathered from the recent genome-wide association study pooled data of the MiBioGen consortium, which included 24 cohorts and 18,340 individuals.

Results

IVW(Inverse variance weighting) revealed that Verrucomicrobia [odds ratio (OR) = 1.390; 95% confidence interval (CI) = 1.10-1.75; p = 0.005], Peptostreptococcaceae (OR = 1.284; 95% CI = 1.03-1.59; p = 0.012), Verrucomicrobiaceae (OR = 1.390; 95% CI = 1.10-1.75; p = 0.005), Akkermansia (OR = 1.390; 95% CI = 1.10-1.75; p = 0.005), Butyricimonas (OR = 1.261; 95% CI = 1.02-1.55; p = 0.031), Catenibacterium (OR = 1.278; 95% CI = 1.02-1.59; p = 0.030).

Conclusion

Two-sample MR analysis identified 12 microbial taxa in gut microbiota (one of which is yet to be officially named) that showed significant causal associations with DN; 8 of these taxa significantly increased the risk of DN, while the remaining 4 taxa (including the one without an official name) reduced the risk of DN. The precise mechanisms influencing the interactions of gut microbiota with DN occurrence remain unclear; hence, additional investigations should be conducted to clarify these mechanisms.

To Explore the Putative Molecular Targets of Diabetic Nephropathy and their Inhibition Utilizing Potential Phytocompounds

BACKGROUND

This review critically addresses the putative molecular targets of Diabetic Nephropathy (DN) and screens effective phytocompounds that can be therapeutically beneficial, and highlights their mechanistic modalities of action.

INTRODUCTION

DN has become one of the most prevalent complications of clinical hyperglycemia, with individual-specific variations in the disease spectrum that leads to fatal consequences. Diverse etiologies involving oxidative and nitrosative stress, activation of polyol pathway, inflammasome formation, Extracellular Matrix (ECM) modifications, fibrosis, and change in dynamics of podocyte functional and mesangial cell proliferation adds up to the clinical complexity of DN. Current synthetic therapeutics lacks target-specific approach, and is associated with the development of inevitable residual toxicity and drug resistance. Phytocompounds provides a vast diversity of novel compounds that can become an alternative therapeutic approach to combat the DN.

METHODS

Relevant publications were searched and screened from research databases like GOOGLE SCHOLAR, PUBMED and SCISEARCH. Out of 4895 publications, the most relevant publications were selected and included in this article.

RESULT

This study critically reviews over 60 most promising phytochemical and provides with their molecular targets, that can be of pharmacological significance in context to current treatment and concomitant research in DN.

CONCLUSION

This review highlights those most promising phytocompounds that have the potential of becoming new safer naturally-sourced therapeutic candidates and demands further attention at clinical level.

The Combinational Effect of Inulin and Resveratrol on the Oxidative Stress and Inflammation Level in a Rat Model of Diabetic Nephropathy

Background

Using inulin can enhance resveratrol's effects by improving the intestinal microbiome and the stability of resveratrol.

Objectives

We aimed to investigate the effect of therapeutic intervention with combined inulin and resveratrol on kidney function in diabetic rats.

Methods

Diabetic model was induced by intraperitoneal injection of streptozotocin. Afterward, rats were divided into 6 groups: control, diabetic without treatment, diabetic treated with insulin, diabetic treated with resveratrol, diabetic treated with inulin, and diabetic treated with a combination of inulin and resveratrol. After 10 wk, the creatinine, urea, insulin, urinary proteins, and inflammatory and oxidative stress markers were evaluated. Pathologic changes were examined in kidney tissues.

Results

Renal dysfunction, accompanied by increased inflammation and oxidative stress, was observed. Our results showed that treatment with resveratrol and inulin had antidiabetic effects and was associated with reduced renal dysfunction, oxidative stress, and kidney inflammation. In addition, it was observed that combined treatment with inulin and resveratrol outperformed monotherapies in improving kidney function and reducing oxidative stress and inflammation.

Conclusions

Treatment with resveratrol and inulin can have renoprotective effects by improving oxidative stress and inflammation in kidney tissues. Therefore, employing these 2 compounds is suggested as an inexpensive and available method for diabetic nephropathy.

In Search of a Function for the N6-Methyladenosine in Epitranscriptome, Autophagy and Neurodegenerative Diseases

Changes in epitranscriptome with N6-methyladenine (m6A) modification could be involved in the development of multiple diseases, which might be a prevalent modification of messenger RNAs (mRNAs) in eukaryotes. The m6A modification might be performed through the action of methyltransferases, demethylases, and methylation-binding proteins. Importantly, the m6A methylation may be associated with various neurological disorders including Alzheimer's disease (AD), Parkinson's disease (PD), depression, aging-related diseases, and/or aging itself. In addition, the m6A methylation might functionally regulate the eukaryotic transcriptome by influencing the splicing, export, subcellular localization, translation, stability, and decay of mRNAs. Neurodegenerative diseases may possess a wide variety of phenotypes, depending on the neurons that degenerate on occasion. Interestingly, an increasing amount of evidence has indicated that m6A modification could modulate the expression of autophagy-related genes and promote autophagy in neuronal cells. Oxidative stresses such as reactive oxygen species (ROS) could stimulate the m6A RNA methylation, which may also be related to the regulation of autophagy and/or the development of neurodegenerative diseases. Both m6A modification and autophagy could also play critical roles in regulating the health condition of neurons. Therefore, a comprehensive understanding of the m6A and autophagy relationship in human diseases may benefit in developing therapeutic strategies in the future. This paper reviews advances in the understanding of the regulatory mechanisms of m6A modification in the occurrence and development of neurodegenerative diseases and/or aging, discussing the possible therapeutic procedures related to mechanisms of m6A RNA methylation and autophagy.

Probiotic Formula Ameliorates Renal Dysfunction Indicators, Glycemic Levels, and Blood Pressure in a Diabetic Nephropathy Mouse Model

One-third of patients with end-stage chronic kidney disease (CKD) experience diabetic nephropathy (DN), which worsens the progression of renal dysfunction. However, preventive measures for DN are lacking. Lactobacillus acidophilus TYCA06, Bifidobacterium longum subsp. infantis BLI-02, and Bifidobacterium bifidum VDD088 probiotic strains have been demonstrated to delay CKD progression. This study evaluated their biological functions to stabilize blood-glucose fluctuations and delay the deterioration of renal function. The db/db mice were used to establish a DN animal model. This was supplemented with 5.125 × 10⁹ CFU/kg/day (high dose) or 1.025 × 10⁹ CFU/kg/day (low dose) mixed with probiotics containing TYCA06, BLI-02, and VDD088 for 8 weeks. Blood urea nitrogen (BUN), serum creatinine, blood glucose, and urine protein were analyzed. Possible mechanisms underlying the alleviation of DN symptoms by probiotic strains were evaluated through in vitro tests. Animal experiments revealed that BUN, serum creatinine, and blood glucose upon probiotic administration were significantly lower than in the control group. The rate of change of urine protein decreased significantly, and blood pressure, glucose tolerance, and renal fibrosis were improved. In vitro testing indicated that TYCA06 and BLI-02 significantly increased acetic acid concentration. TYCA06, BLI-02, and VDD088 were associated with better antioxidation, anti-inflammation, and glucose consumption activities relative to the control. A combination of the probiotics TYCA06, BLI-02, and VDD088 attenuated renal function deterioration and improved blood-glucose fluctuation in a diabetes-induced CKD mouse model.

Advantageous tactics with certain probiotics for the treatment of graft-versus-host-disease after hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) becomes a standard form of cellular therapy for patients with malignant diseases. HSCT is the first-choice of immunotherapy, although HSCT can be associated with many complications such as graft-versus-host disease (GVHD) which is a major cause of morbidity and mortality after allogeneic HSCT. It has been shown that certain gut microbiota could exert protective and/or regenerative immunomodulatory effects by the production of short-chain fatty acids (SCFAs) such as butyrate in the experimental models of GVHD after allogeneic HSCT. Loss of gut commensal bacteria which can produce SCFAs may worsen dysbiosis, increasing the risk of GVHD. Expression of G-protein coupled receptors such as GPR41 seems to be upre-gulated in the presence of commensal bacteria, which might be associated with the biology of regulatory T cells (Tregs). Treg cells are a suppressive subset of CD4 positive T lymphocytes implicated in the prevention of GVHD after allogeneic HSCT. Here, we discuss the current findings of the relationship between the modification of gut microbiota and the GVHD-related immunity, which suggested that tactics with certain probiotics for the beneficial symbiosis in gut-immune axis might lead to the elevation of safety in the allogeneic HSCT.

The role and mechanism of the gut microbiota in the development and treatment of diabetic kidney disease

Diabetic kidney disease (DKD) is a common complication in patients with diabetes mellitus (DM). Increasing evidence suggested that the gut microbiota participates in the progression of DKD, which is involved in insulin resistance, renin-angiotensin system (RAS) activation, oxidative stress, inflammation and immunity. Gut microbiota-targeted therapies including dietary fiber, supplementation with probiotics or prebiotics, fecal microbiota transplantation and diabetic agents that modulate the gut microbiota, such as metformin, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, and sodium-glucose transporter-2 (SGLT-2) inhibitors. In this review, we summarize the most important findings about the role of the gut microbiota in the pathogenesis of DKD and the application of gut microbiota-targeted therapies.

Sacubitril/Valsartan contributes to improving the diabetic kidney disease and regulating the gut microbiota in mice

Background

Diabetic kidney disease (DKD), as a serious microvascular complication of diabetes, has limted treatment options. It is reported that the Sacubitril/Valsartan (Sac/Val) can improve kidney function, and the disordered gut microbiota and part of its metabolites are related to the development of DKD. Therefore, we aim to explore whether the effect of Sac/Val on DKD is associated with the gut microbiota and related plasma metabolic profiles.

Methods

Male C57BL/6J mice were randomly divided into 3 groups: Con group (n = 5), DKD group (n = 6), and Sac/Val group (n = 6) . Sac/Val group was treated with Sac/Val solution. The intervention was given once every 2 days for 6 weeks. We measured the blood glucose and urine protein level of mice at different times. We then collected samples at the end of experiment for the 16s rRNA gene sequencing analysis and the untargeted plasma metabonomic analysis.

Results

We found that the plasma creatinine concentration of DKD-group mice was significantly higher than that of Con-group mice, whereas it was reduced after the Sac/Val treatment. Compared with DKD mice, Sac/Val treatment could decrease the expression of indicators related to EndMT and renal fibrosis like vimentin, collagen IV and fibronectin in kidney. According to the criteria of LDA ≥ 2.5 and p<0.05, LefSe analysis of gut microbiota identified 13 biomarkers in Con group, and 33 biomarkers in DKD group, mainly including Prevotella, Escherichia_Shigella and Christensenellaceae_R_7_group, etc. For the Sac/Val group, there were 21 biomarkers, such as Bacteroides, Rikenellaceae_RC9_gut_group, Parabacteroides, Lactobacillus, etc. Plasma metabolomics analysis identified a total of 648 metabolites, and 167 important differential metabolites were screened among groups. KEGG pathway of tryptophan metabolism: M and bile secretion: OS had the highest significance of enrichment.

Conclusions

Sac/Val improves the renal function of DKD mice by inhibiting renal fibrosis. This drug can also regulate gut microbiota in DKD mice.

Nephro-protective effect of Daphnetin in hyperoxaluria-induced rat renal injury via alterations of the gut microbiota

It is well proved that hyperoxaluria induces the renal injury and finally causes the end stage kidney disease. Daphnetin (coumarin derivative) already confirmed renal protective effect in renal model, but hyperoxaluria protective effect still unexplore. The objective of this research was to scrutinize the renal protective effect of daphnetin against ethylene glycol (GC)-induced hyperoxaluria via altering the gut microbiota. GC (1% v/v) was used for the induction of hyperoxaluria in the rats and the rats were received the oral administration of daphnetin (5, 10 and 15 mg/kg). The body and renal weight were assessed. Urine, renal, inflammatory cytokines, antioxidant, inflammatory parameters, and gut microbiota were appraised. Daphnetin effectually improved the body weight and reduced the renal weight. Its also remarkably boosted the magnesium, calcium, citrate level and suppressed the level of uric acid and oxalate formation. Daphnetin significantly (p < .001) ameliorate the level of urinary kidney injury molecule 1 (KIM-1), blood urea nitrogen (BUN), urea, serum creatinine (Scr), neutrophil gelatinase-associated lipocalin (NGAL) and uric acid along with inflammatory cytokines and inflammatory mediators. Daphnetin considerably repressed the malonaldehyde (MDA) level, protein carbonyl and improved the level of glutathione reductase (GR), superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT). Daphnetin treatment considerably altered the microbial composition of different bacteria at phylum, genus and family level. Daphnetin significantly suppressed the Firmicutes relative abundance and boosted the Bacteroidetes relative abundance. Our result clearly indicated that daphnetin remarkably ameliorates the GC induced hyperoxaluria in rats via altering the oxidative stress, inflammatory reaction and gut microbiota. PRACTICAL APPLICATION: Nephrotoxicity is a serious health disease worldwide. We induce the renal toxicity in the experimental rats using the ethylene glycol and scrutinized the renal protective effect of daphnetin. Daphnetin considerably suppress the renal, urine parameters. For estimation the underlying mechanism, we estimated the gut microbiota in all group rats. Daphnetin remarkably altered the level of gut microbiota and suggesting the renal protective effect.

Renal Health Improvement in Diabetes through Microbiome Modulation of the Gut-Kidney Axis with Biotics: A Systematic and Narrative Review of Randomized Controlled Trials

Diabetes mellitus is the most common endocrine disorder worldwide, with over 20% of patients ultimately developing diabetic kidney disease (DKD), a complex nephropathic complication that is a leading cause of end-stage renal disease. Various clinical trials have utilized probiotics, prebiotics, and synbiotics to attempt to positively modulate the gut microbiome via the gut-kidney axis, but consensus is limited. We conducted a multi-database systematic review to investigate the effect of probiotics, prebiotics, and synbiotics on various biomarkers of renal health in diabetes, based on studies published through 10 April 2022. Adhering to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, relevant articles were systematically screened and extracted by independent reviewers; subsequently, results were systematically compiled, analyzed, and expanded through a narrative discussion. A total of 16 publications encompassing 903 diabetic individuals met the inclusion criteria. Our findings show that some studies report statistically significant changes in common renal markers, such as serum creatinine, estimated glomerular filtration rate, blood urea nitrogen/urea, microalbuminuria, and uric acid, but not on serum albumin, sodium, potassium, phosphorous, or total urine protein. Interestingly, these nutraceuticals seem to increase serum uric acid concentrations, an inflammatory marker usually associated with decreased renal health. We found that probiotics from the Lactobacillus and Bifidobacterium families were the most investigated, followed by Streptococcus thermophilus. Prebiotics including inulin, galacto-oligosaccharide, and resistant dextrin were also examined. The single-species probiotic soymilk formulation of Lactobacillus plantarum A7 possessed effects on multiple renal biomarkers in DKD patients without adverse events. We further investigated the optimum nutraceutical formulation, discussed findings from prior studies, described the gut-kidney axis in diabetes and DKD, and finally commented on some possible mechanisms of action of these nutraceuticals on renal health in diabetics. Although probiotics, prebiotics, and synbiotics have shown some potential in ameliorating renal health degradation in diabetes via gut-kidney axis crosstalk, larger and more convincing trials with focused objectives and next-generation nutraceutical formulations are required to investigate their possible role as adjunct therapy in such patients.