Modulation of Gut Microbiota in End-stage Renal Disease (MGM-dialysis)
Modulation of Gut Microbiota in End-stage Renal Disease: A Pilot Study
調査の概要
詳細な説明
Chronic kidney disease (CKD) has a prevalence of 10% in the general population and up to 20% in high-risk groups, such as patients with diabetes. Despite the widespread availability of renal replacement therapy in the western world, mortality of patients with end-stage renal disease (ESRD) is still high. The life expectancy of patients with renal replacement therapy in Austria is reduced by more than 50%.
Patients on renal replacement therapy exhibit an increased cardiovascular mortality (10-30 fold higher than in the general population) associated with accelerated vascular calcification. The KIDNEY DISEASE IMPROVING GLOBAL OUTCOMES (KDIGO)-work group introduced the term CKD-Mineral and Bone Disorder (CKD-MBD) which describes a clinical syndrome encompassing mineral, bone, and calcific cardio-vascular abnormalities that develop as a complication of CKD. This syndrome emerges as a result of a declining kidney function and is characterized by changes of circulating levels of parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D),1,25-dihydroxyvitamin D (1,25(OH)2D), other vitamin D metabolites and fibroblast growth factor-23 (FGF-23). The ability of the failing kidneys to excrete phosphate is diminished and hyperphosphatemia occurs. High phosphate levels together with calcium as well as low concentrations of fetuin A, the main calcification inhibitor under physiological conditions, lead to increased vascular and extravascular calcification and renal bone disease. Another important calcification inhibitor is the vitamin K2-dependent matrix Gla-protein (MGP). Dialysis patients exhibit a low vitamin K intake and suffer substantially from vitamin K deficiency. Insufficient vitamin K intake leads to the production of non-carboxylated, inactive MGP and deficiency of carboxylated MGP may contribute substantially to the development and progression of arterial calcification. Bacterial infection and sepsis, although decreasing over the last decades, also account for up to 20% of deaths in ESRD-patients and are the second most common cause of mortality and hospitalization. Mortality due to sepsis is 100 - 300 times higher in dialysis patients as compared to the general population. The mechanisms of the increased susceptibility to infection are unclear but recent studies suggest that in patients with ESRD, innate immune response is defective. One reason for defective innate immunity might lie in an increased risk for endotoxemia. Hemodialysis (HD)-induced regional splanchnic ischemia leads to increased gut permeability and consecutive endotoxin translocation. This possibly results in alterations in gut microbiome composition.
Recently profound alterations of the composition of the gut microbiome in ESRD have been shown. In ESRD subjects, more Firmicutes, Actinobacteria and Proteobacteria and fewer Sutterellaceae, Bacteroidaceae, and Lactobacillaceae were observed relative to controls. The frequent use of antibiotics, phosphate binders and an often polypragmatic drug consumption has a considerable impact on the microbiome of ESRD-patients.
These alterations of gut microbiota can impact on several mechanisms in ESRD. Gut bacteria produce vitamin K and the microbiome composition might therefore play a pivotal role in providing enough vitamin K for a sufficient carboxylation of MGP, a potent inhibitor of arterial calcification. Treatment with vitamin K antagonists, for example, has been associated with a 10 fold increased risk for the development of calcification and calciphylaxis, a life threatening calcifying arteriolopathy in CKD-patients. Furthermore the gut is a potential source of endotoxin in patients with ESRD, due to translocation of bacterial products across the gastrointestinal barrier. In ESRD the presence of endotoxin is an independent predictor for mortality. Ultrafiltration during hemodialysis treatment leads to critical ischemia in the splanchnic vascular bed, thus adversely affecting the integrity of the gut barrier. Disruption of gut barrier function in ESRD allows translocation of endotoxin and bacterial metabolites to the systemic circulation, which contributes to inflammation and uremia and prompts progression of the disease. Furthermore, subclinical inflammation in ESRD-patients has been shown to promote progression of cardiovascular disease as well. The gut microbiome also impacts on glucose metabolism and plays a critical role in obesity and the development of insulin resistance and type 2 diabetes. Protein fermentation by gut microbiota generates toxic metabolites and many of the known uremic toxins are of intestinal origin, including p-cresol and indoxyl sulfate. Modulation of the microbiome can contribute to the reduction/elimination of uremic toxins.
Improving the poor prognosis of ESRD patients is an ongoing challenge. An increased awareness of the limitations in conventional dialysis techniques has renewed interest in alternative therapeutics in recent years. An unmet clinical need for adjuvant therapeutic strategies persists in patients whether renal transplantation is intended or not. Supplementation of probiotics and thereby targeting the intestine, an important source of endotoxin and uremic toxins, might be a promising approach to partly overcome the high morbidity and mortality in ESRD patients. Probiotics are living beneficial microorganisms, able to gastroduodenal passage and maintain viability throughout the gut. Feasibility of gut microbiome modulation in ESRD was shown in animal and human settings. However, so far, it is unknown to what extend probiotics are able to re-establish gut microbiome homeostasis in ESRD. Furthermore the effects of a probiotic intervention on cardiovascular risk factors, inflammation, gut barrier and uremia have not been studied in detail yet.
研究の種類
段階
- 適用できない
連絡先と場所
研究場所
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Graz、オーストリア、8010
- Department of Internal Medicine, Medical University of Graz
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参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
説明
Inclusion Criteria:
- Informed consent
- Patients with end-stage renal disease [5] undergoing any modality of renal replacement therapy (hemodialysis, hemodiafiltration or peritoneal dialysis)
Exclusion Criteria:
- Malignancy
- Pregnancy
- Chronic inflammatory bowel disease
- Celiac disease
- Active alcohol abuse (>40g alcohol per day)
Any severe organ dysfunction unrelated to renal dysfunction
20 healthy family members (living in the same household) of patients will be recruited as controls
研究計画
研究はどのように設計されていますか?
デザインの詳細
- 主な目的:防止
- 割り当て:ランダム化
- 介入モデル:並列代入
- マスキング:4倍
武器と介入
参加者グループ / アーム |
介入・治療 |
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アクティブコンパレータ:Probiotic
6 g of Winclove-849 containing Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, Lactobacillus casei W56, Lactobacillus salivarius W24, Lactococcus lactis W19, Lactococcus lactis W58 at a concentration of 2.5 x 109 cfu/g
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multispecies probiotic
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プラセボコンパレーター:Placebo
similar looking and tasting placebo without bacteria
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matrix
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この研究は何を測定していますか?
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
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Gut microbiome
時間枠:1 year
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changes in gut microbiome composition
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1 year
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二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
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gut permeability (zonulin in stool)
時間枠:1 year
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changes in gut permeability
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1 year
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bacterial translocation (bacterial DNA in serum)
時間枠:1 year
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decrease in bacterial translocation
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1 year
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neutrophil phagocytic capacity
時間枠:1 year
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improvement in neutrophil function
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1 year
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glucose metabolism (meal tolerance test)
時間枠:1 year
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improvement in glucose metabolism
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1 year
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uremia toxins
時間枠:1 year
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decrease in uremia toxins
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1 year
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協力者と研究者
捜査官
- 主任研究者:Vanessa Stadlbauer, MD、Medical University of Graz
- 主任研究者:Harald Sourij, MD、Medical University of Graz
研究記録日
主要日程の研究
研究開始
一次修了 (予想される)
研究の完了 (予想される)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
この情報は、Web サイト clinicaltrials.gov から変更なしで直接取得したものです。研究の詳細を変更、削除、または更新するリクエストがある場合は、register@clinicaltrials.gov。 までご連絡ください。 clinicaltrials.gov に変更が加えられるとすぐに、ウェブサイトでも自動的に更新されます。
Probioticの臨床試験
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Vancouver Island Health AuthorityCanadian Society of Hospital Pharmacists; Jamieson Laboratories Ltd, Canada終了しました