The Alteration human of gut microbiota and metabolites before and after renal transplantation

Kidney transplantation and gut microbiota

Kidney transplantation is an effective way to improve the condition of patients with end-stage renal disease. However, maintaining long-term graft function and improving patient survival remain a key challenge after kidney transplantation. Dysbiosis of intestinal flora has been reported to be associated with complications in renal transplant recipients. The commensal microbiota plays an important role in the immunomodulation of the transplant recipient responses. However, several processes, such as the use of perioperative antibiotics and high-dose immunosuppressants in renal transplant recipients, can lead to gut dysbiosis and disrupt the interaction between the microbiota and the host immune responses, which in turn can lead to complications such as infection and rejection in organ recipients. In this review, we summarize and discuss the changes in intestinal flora and their influencing factors in patients after renal transplantation as well as the evidence related to the impact of intestinal dysbiosis on the prognosis of renal transplantation from in vivo and clinical studies, and conclude with a discussion of the use of microbial therapy in the transplant population. Hopefully, a deeper understanding of the function and composition of the microbiota in patients after renal transplantation may assist in the development of clinical strategies to restore a normal microbiota and facilitate the clinical management of grafts in the future.

Update on the reciprocal interference between immunosuppressive therapy and gut microbiota after kidney transplantation

Gut microbiota is often modified after kidney transplantation. This principally happens in the first period after transplantation. Antibiotics and, most of all, immunosuppressive drugs are the main responsible. The relationship between immunosuppressive drugs and the gut microbiota is bilateral. From one side immunosuppressive drugs modify the gut microbiota, often generating dysbiosis; from the other side microbiota may interfere with the immunosuppressant pharmacokinetics, producing products more or less active with respect to the original drug. These phenomena have influence over the graft outcomes and clinical consequences as rejections, infections, diarrhea may be caused by the dysbiotic condition. Corticosteroids, calcineurin inhibitors such as tacrolimus and cyclosporine, mycophenolate mofetil and mTOR inhibitors are the immunosuppressive drugs whose effect on the gut microbiota is better known. In contrast is well known how the gut microbiota may interfere with glucocorticoids, which may be transformed into androgens. Tacrolimus may be transformed by micro biota into a product called M1 that is 15-fold less active with respect to tacrolimus. The pro-drug mycophenolate mofetil is normally transformed in mycophenolic acid that according the presence or not of microbes producing the enzyme glu curonidase, may be transformed into the inactive product.

Facile preparation of nitrogen/titanium-rich porous organic polymers for specific enrichment of N-glycopeptides and phosphopeptides

The comprehensive investigation of protein phosphorylation and glycosylation aids in the discovery of novel biomarkers as well as the understanding of the pathophysiology of illness. In this work, a nitrogen/titanium-rich porous organic polymer was developed by copolymerizing carbohydrazide (CH) and 2,3-dihydroxyterephthalaldehyde (2,3-Dha) and modifying with Ti4+ (CH-Dha-Ti4+). The adequate nitrogen contributes to the enrichment of glycopeptides via HILIC, while titanium benefits from capturing phosphopeptides through IMAC. The proposed method exhibits excellent selectivity (1 : 1000, both for glycopeptides and phosphopeptides), LOD (for glycopeptides: 0.05 fmol μL-1, for phosphopeptides: 0.2 fmol), loading capacity (for glycopeptides: 100 mg g-1, for phosphopeptides: 125 mg g-1) and size-exclusion effect (1 : 10 000, both for glycopeptides and phosphopeptides). Furthermore, CH-Dha-Ti4+ was applied to capture glycopeptides and phosphopeptides from human serum; 205 glycopeptides and 45 phosphopeptides were detected in the serum of normal controls; and 294 glycopeptides and 63 phosphopeptides were found in the serum of uremia patients after being analyzed by nano LC-MS/MS. The discovered glycopeptides and phosphopeptides were involved in several molecular biological processes and activities, according to a gene ontology study.

Fecal Microbiota Transplantation in Reducing Uremic Toxins Accumulation in Kidney Disease: Current Understanding and Future Perspectives

During the past decades, the gut microbiome emerged as a key player in kidney disease. Dysbiosis-related uremic toxins together with pro-inflammatory mediators are the main factors in a deteriorating kidney function. The toxicity of uremic compounds has been well-documented in a plethora of pathophysiological mechanisms in kidney disease, such as cardiovascular injury (CVI), metabolic dysfunction, and inflammation. Accumulating data on the detrimental effect of uremic solutes in kidney disease supported the development of many strategies to restore eubiosis. Fecal microbiota transplantation (FMT) spread as an encouraging treatment for different dysbiosis-associated disorders. In this scenario, flourishing studies indicate that fecal transplantation could represent a novel treatment to reduce the uremic toxins accumulation. Here, we present the state-of-the-art concerning the application of FMT on kidney disease to restore eubiosis and reverse the retention of uremic toxins.

The Gut Microbiota in Kidney Transplantation: A Target for Personalized Therapy?

Kidney transplantation improves quality of life, morbidity, and mortality of patients with kidney failure. However, integrated immunosuppressive therapy required to preserve graft function is associated with the development of post-transplant complications, including infections, altered immunosuppressive metabolism, gastrointestinal toxicity, and diarrhea. The gut microbiota has emerged as a potential therapeutic target for personalizing immunosuppressive therapy and managing post-transplant complications. This review reports current evidence on gut microbial dysbiosis in kidney transplant recipients, alterations in their gut microbiota associated with kidney transplantation outcomes, and the application of gut microbiota intervention therapies in treating post-transplant complications.