A synbiotic supplement for inflammation and oxidative stress and lipid abnormalities in hemodialysis patients

Beneficial effects of the probiotics and synbiotics supplementation on anthropometric indices and body composition in adults: A systematic review and meta-analysis

Studies have suggested that probiotics and synbiotics can improve body weight and composition. However, randomized controlled trials (RCTs) demonstrated mixed results. Hence, we performed a systematic review and meta-analysis to evaluate the effectiveness of probiotics and synbiotics on body weight and composition in adults. We searched PubMed/Medline, Ovid/Medline, Scopus, ISI Web of Science, and Cochrane library up to April 2023 using related keywords. We included all RCTs investigating the effectiveness of probiotics and/or synbiotics supplementation on anthropometric indices and body composition among adults. Random-effects models were applied for performing meta-analyses. In addition, we conducted subgroup analyses and meta-regression to explore the non-linear and linear relationship between the length of follow-up and the changes in each outcome. We included a total of 200 trials with 12,603 participants in the present meta-analysis. Probiotics or synbiotics intake led to a significant decrease in body weight (weighted mean difference [WMD]: -0.91 kg; 95% CI: -1.08, -0.75; p < 0.001), body mass index (BMI) (WMD: -0.28 kg/m2 ; 95% CI: -0.36, -0.21; p < 0.001), waist circumference (WC) (WMD: -1.14 cm; 95% CI: -1.42, -0.87; p < 0.001), waist-to-hip ratio (WHR) (WMD: -0.01; 95% CI: -0.01, -0.00; p < 0.001), fat mass (FM) (WMD: -0.92 kg; 95% CI: -1.05, -0.79; p < 0.001), and percentage of body fat (%BF) (WMD: -0.68%; 95% CI: -0.94, -0.42; p < 0.001) compared to controls. There was no difference in fat-free mass (FFM) and lean body mass (LBM). Subgroup analyses indicated that probiotics or synbiotics administered as food or supplement resulted in significant changes in anthropometric indices and body composition. However, compared to controls, FM and %BF values were only reduced after probiotic consumption. Our results showed that probiotics or synbiotics have beneficial effects on body weight, central obesity, and body composition in adults and could be useful as an add on to weight loss products and medications.

Fortified synbiotic dessert for improving malnutrition in hemodialysis patients: A randomized, double-blind, controlled trial

As dysbiosis of gut microbiota is recognized as a major risk factor for malnutrition in hemodialysis (HD) patients, we aimed to assess the effects of fortified synbiotic dessert on malnutrition, oxidative stress, inflammation, and quality of life in patients undergoing hemodialysis. A total of 50 hemodialysis patients were randomized into two groups of intervention and control to consume either 50 g of synbiotic dessert fortified with vitamin D (1000 IU) and calcium (500 mg) (FSD) or 50 g of control dessert (CD) for 8 weeks, respectively. Changes in nutritional status [Subjective Global Assessment (SGA)], anthropometric measures, malondialdehyde (MDA), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP), ferritin, biochemistry [serum albumin, vitamin D, creatinine, blood urea nitrogen (BUN), complete blood count (CBC), and electrolytes], and quality of life were assessed before and at the end of the trial. The SGA scores and serum ferritin levels decreased significantly in the FSD group compared to the control group (p = .01 and p = .03, respectively). Regarding other markers, no statistically significant changes were found comparing the two groups. This novel fortified synbiotic dessert as a functional food may be effective in reducing the severity of malnutrition by improving SGA score in short term in hemodialysis patients. Thus, it is suggested to do further studies to elucidate the possible mechanisms related to the effects of this dessert on microbiota, skeletal muscle mass, and inflammation in HD in long term.

Effects of Probiotic-Enriched Minas Cheese (Lactobacillus acidophilus La-05) on Cardiovascular Parameters in 5/6 Nephrectomized Rats

Dairy foods have become an interest in chronic kidney disease (CKD) due to their nutritional profile, which makes them a good substrate for probiotics incorporation. This study evaluated the effect of probiotic-enriched Minas cheese with Lactobacillus acidophilus La-05 in an experimental rat model for CKD on cardiac, inflammatory, and oxidative stress parameters. Male Wistar rats were divided into 4 groups (n = 7/group): 5/6 nephrectomy + conventional Minas cheese (NxC); 5/6 nephrectomy + probiotic Minas cheese (NxPC); Sham + conventional Minas cheese (ShamC); Sham + probiotic Minas cheese (ShamPC). Offering 20 g/day of Minas cheese with Lact. acidophilus La-05 (108-109 log CFU/g) for 6 weeks. The cardiomyocyte diameter was determined. Superoxide dismutase (SOD) activity in plasma, heart, kidney, and colon tissue was performed. At the end of supplementation, no significant changes in lipid profile and renal parameters were found. The NxPC group showed a decrease in cardiomyocyte diameter compared to the NxC group (16.99 ± 0.85 vs. 19.05 ± 0.56 μm, p = 0.0162); also they showed reduced plasmatic SOD activity (502.8 ± 49.12 vs. 599.4 ± 94.69 U/mL, p < 0.0001). In summary, probiotic-enriched Minas cheese (Lact. acidophilus La-05) consumption suggests a promisor cardioprotective effect and was able to downregulate SOD activity in a rat model of CKD.

Effects of anti-Inflammatory-antioxidant-rich diet and co-supplemented synbiotics intervention in patients with progressive forms of multiple sclerosis: a single-center, single-blind randomized clinical trial

BACKGROUND

Current evidence has demonstrated that patients with Multiple Sclerosis (MS) have dysbiotic gut microbiomes, and anti-inflammatory nutritional interventions can normalize this status. Therefore, we aimed to investigate the effects of dietary intervention in patients with progressive forms of MS.

METHODS

Seventy patients with three forms of progressive MS (primary-progressive, secondary-progressive, and progressive-relapsing) were randomly assigned into intervention (daily synbiotics capsule plus anti-inflammatory-antioxidant rich diet) or control (placebo capsule plus dietary recommendations) groups for four months. Faecal calprotectin level, Impact of Vision Impairment (IVI), Gastrointestinal Symptom Rating Scale (GSRS), and anthropometric measurements were evaluated at baseline and trial cessation. Analysis of covariance was conducted and adjusted for age, gender, education level, family history & duration of MS, type of progressive MS, type of main drug, and physical activity.

RESULTS

Sixty-nine participants were included in the final analysis (n of intervention = 34; n of control = 35). Synbiotics and dietary intervention significantly reduced Faecal calprotectin level after six months (110.5 ± 75.9-44.7 ± 49.3 ɥg/g, P < 0.001), and mean changes were statistically significant in comparison with control group. However, intervention did not elicit any change in the anthropometric measurements.

CONCLUSION

Synbiotics supplementation and adherence to an anti-inflammatory-antioxidant-rich diet reduced intestinal inflammation and improved clinical manifestations in progressive forms of MS.Trial registration: Iranian Registry of Clinical Trials identifier: IRCT20141108019853N7..

Synbiotics, prebiotics and probiotics for people with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a major public health problem affecting 13% of the global population. Prior research has indicated that CKD is associated with gut dysbiosis. Gut dysbiosis may lead to the development and/or progression of CKD, which in turn may in turn lead to gut dysbiosis as a result of uraemic toxins, intestinal wall oedema, metabolic acidosis, prolonged intestinal transit times, polypharmacy (frequent antibiotic exposures) and dietary restrictions used to treat CKD. Interventions such as synbiotics, prebiotics, and probiotics may improve the balance of the gut flora by altering intestinal pH, improving gut microbiota balance and enhancing gut barrier function (i.e. reducing gut permeability).

OBJECTIVES

This review aimed to evaluate the benefits and harms of synbiotics, prebiotics, and probiotics for people with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 9 October 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) measuring and reporting the effects of synbiotics, prebiotics, or probiotics in any combination and any formulation given to people with CKD (CKD stages 1 to 5, including dialysis and kidney transplant). Two authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was independently carried out by two authors using a standard data extraction form. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Forty-five studies (2266 randomised participants) were included in this review. Study participants were adults (two studies in children) with CKD ranging from stages 1 to 5, with patients receiving and not receiving dialysis, of whom half also had diabetes and hypertension. No studies investigated the same synbiotic, prebiotic or probiotic of similar strains, doses, or frequencies. Most studies were judged to be low risk for selection bias, performance bias and reporting bias, unclear risk for detection bias and for control of confounding factors, and high risk for attrition and other biases. Compared to prebiotics, it is uncertain whether synbiotics improve estimated glomerular filtration rate (eGFR) at four weeks (1 study, 34 participants: MD -3.80 mL/min/1.73 m², 95% CI -17.98 to 10.38), indoxyl sulfate at four weeks (1 study, 42 participants: MD 128.30 ng/mL, 95% CI -242.77 to 499.37), change in gastrointestinal (GI) upset (borborymgi) at four weeks (1 study, 34 participants: RR 15.26, 95% CI 0.99 to 236.23), or change in GI upset (Gastrointestinal Symptom Rating Scale) at 12 months (1 study, 56 participants: MD 0.00, 95% CI -0.27 to 0.27), because the certainty of the evidence was very low. Compared to certain strains of prebiotics, it is uncertain whether a different strain of prebiotics improves eGFR at 12 weeks (1 study, 50 participants: MD 0.00 mL/min, 95% CI -1.73 to 1.73), indoxyl sulfate at six weeks (2 studies, 64 participants: MD -0.20 μg/mL, 95% CI -1.01 to 0.61; I² = 0%) or change in any GI upset, intolerance or microbiota composition, because the certainty of the evidence was very low. Compared to certain strains of probiotics, it is uncertain whether a different strain of probiotic improves eGFR at eight weeks (1 study, 30 participants: MD -0.64 mL/min, 95% CI -9.51 to 8.23; very low certainty evidence). Compared to placebo or no treatment, it is uncertain whether synbiotics improve eGFR at six or 12 weeks (2 studies, 98 participants: MD 1.42 mL/min, 95% CI 0.65 to 2.2) or change in any GI upset or intolerance at 12 weeks because the certainty of the evidence was very low. Compared to placebo or no treatment, it is uncertain whether prebiotics improves indoxyl sulfate at eight weeks (2 studies, 75 participants: SMD -0.14 mg/L, 95% CI -0.60 to 0.31; very low certainty evidence) or microbiota composition because the certainty of the evidence is very low. Compared to placebo or no treatment, it is uncertain whether probiotics improve eGFR at eight, 12 or 15 weeks (3 studies, 128 participants: MD 2.73 mL/min, 95% CI -2.28 to 7.75; I² = 78%), proteinuria at 12 or 24 weeks (1 study, 60 participants: MD -15.60 mg/dL, 95% CI -34.30 to 3.10), indoxyl sulfate at 12 or 24 weeks (2 studies, 83 participants: MD -4.42 mg/dL, 95% CI -9.83 to 1.35; I² = 0%), or any change in GI upset or intolerance because the certainty of the evidence was very low. Probiotics may have little or no effect on albuminuria at 12 or 24 weeks compared to placebo or no treatment (4 studies, 193 participants: MD 0.02 g/dL, 95% CI -0.08 to 0.13; I² = 0%; low certainty evidence). For all comparisons, adverse events were poorly reported and were minimal (flatulence, nausea, diarrhoea, abdominal pain) and non-serious, and withdrawals were not related to the study treatment.

AUTHORS' CONCLUSIONS

We found very few studies that adequately test biotic supplementation as alternative treatments for improving kidney function, GI symptoms, dialysis outcomes, allograft function, patient-reported outcomes, CVD, cancer, reducing uraemic toxins, and adverse effects. We are not certain whether synbiotics, prebiotics, or probiotics are more or less effective compared to one another, antibiotics, or standard care for improving patient outcomes in people with CKD. Adverse events were uncommon and mild.

Anti-Inflammatory Effects of Lipid-Lowering Drugs and Supplements-A Narrative Review

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Since the establishment of the "lipid hypothesis", according to which, cholesterol level is directly correlated to the risk of CVD, many different lipid-lowering agents have been introduced in clinical practice. A majority of these drugs, in addition to their lipid-lowering properties, may also exhibit some anti-inflammatory and immunomodulatory activities. This hypothesis was based on the observation that a decrease in lipid levels occurs along with a decrease in inflammation. Insufficient reduction in the inflammation during treatment with lipid-lowering drugs could be one of the explanations for treatment failure and recurrent CVD events. Thus, the aim of this narrative review was to evaluate the anti-inflammatory properties of currently available lipid-lowering medications including statins, ezetimibe, bile acid sequestrants (BAS), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fibrates, omega-3 fatty acids, and niacin, as well as dietary supplements and novel drugs used in modern times.

Probiotics, Prebiotics, and Synbiotics for Patients on Dialysis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The current systematic review and meta-analysis investigated the effects of probiotic, prebiotic, and synbiotic administration on inflammation, metabolic parameters, nutritional status, and uremic toxin in dialysis patients.

METHODS

Up to June 2021, publications were searched in Cochrane Library, PubMed, EMBASE, and Web of Science databases. The protocol was submitted to the International Prospective Register of Systematic Reviews and was approved.

RESULTS

This meta-analysis included 18 randomized controlled trials which were eligible. This meta-analysis discovered that probiotic, prebiotic, and synbiotic supplements could reduce C-reactive protein (standardized mean difference (SMD), -0.38; 95% confidence interval (CI), -0.68 to -0.08; P = .01), interleukin 6 (SMD, -0.48; 95% CI, -0.76 to -0.20; P = .00), and indoxyl sulfate (SMD, -0.24; 95% CI, -0.48 to -0.01; P = .045) and increase high-density lipoprotein cholesterol (SMD, 0.25; 95% CI, 0.03 to 0.46; P = .025) compared with the control group but had no significant influence on tumor necrosis factor α, albumin, hemoglobin, triglyceride, total cholesterol, low-density lipoprotein cholesterol, calcium, phosphorus, uric acid, or p-cresyl sulfate in dialysis patients.

CONCLUSIONS

Probiotic, prebiotic, and synbiotic administration could reduce C-reactive protein, interleukin 6, and indoxyl sulfate and increase high-density lipoprotein cholesterol in dialysis patients. To better examine the impact, large-scale, long-term, controlled diets and well-designed randomized controlled trials are needed.

Effectiveness of Microecological Preparations for Improving Renal Function and Metabolic Profiles in Patients With Chronic Kidney Disease

Background

Determining whether microecological preparations, including probiotics, prebiotics, and synbiotics, are beneficial for patients with chronic kidney disease (CKD) has been debated. Moreover, determining which preparation has the best effect remains unclear. In this study, we performed a network meta-analysis of randomized clinical trials (RCTs) to address these questions.

Methods

MEDLINE, EMBASE, PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials were searched. Eligible RCTs with patients with CKD who received intervention measures involving probiotics, prebiotics, and/or synbiotics were included. The outcome indicators included changes in renal function, lipid profiles, inflammatory factors, and oxidative stress factors.

Results

Twenty-eight RCTs with 1,373 patients were ultimately included. Probiotics showed greater effect in lowering serum creatinine [mean difference (MD) -0.21, 95% confidence interval (CI) -0.34, -0.09] and triglycerides (MD -9.98, 95% CI -19.47, -0.49) than the placebo, with the largest surface area under the cumulative ranking curve, while prebiotics and synbiotics showed no advantages. Probiotics were also able to reduce malondialdehyde (MDA) (MD -0.54, 95% CI -0.96, -0.13) and increase glutathione (MD 72.86, 95% CI 25.44, 120.29). Prebiotics showed greater efficacy in decreasing high-sensitivity C-reactive protein (MD -2.06, 95% CI -3.79, -0.32) and tumor necrosis factor-α (MD -2.65, 95% CI -3.91, -1.39). Synbiotics showed a partially synergistic function in reducing MDA (MD -0.66, 95% CI -1.23, -0.09) and high-sensitivity C-reactive protein (MD -2.01, 95% CI -3.87, -0.16) and increasing total antioxidant capacity (MD 145.20, 95% CI 9.32, 281.08).

Conclusion

The results indicated that microbial supplements improved renal function and lipid profiles and favorably affected measures of oxidative stress and inflammation in patients with CKD. After thorough consideration, probiotics provide the most comprehensive and beneficial effects for patients with CKD and might be used as the best choice for microecological preparations.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022295497, PROSPERO 2022, identifier: CRD42022295497.

Probiotics, Prebiotics, and Synbiotics Improve Uremic, Inflammatory, and Gastrointestinal Symptoms in End-Stage Renal Disease With Dialysis: A Network Meta-Analysis of Randomized Controlled Trials

Background

Probiotics, prebiotics, and synbiotics are three different supplements to treat end stage renal disease (ESRD) patients by targeting gut bacteria. The comprehensive comparison of the effectiveness of different supplements are lacking.

Objectives

The purpose of this network meta-analysis (NMA) is to assess and rank the efficacy of probiotics, prebiotics, and synbiotics on inflammatory factors, uremic toxins, and gastrointestinal symptoms (GI symptoms) in ESRD patients undergoing dialysis.

Methods

Randomized clinical trials were searched from the PubMed, Embase, and Cochrane Register of Controlled Trials databases, from their inception until 4 September 2021. Random-effect model were used to obtain all estimated outcomes in network meta-analysis (NMA). Effect estimates were presented as mean differences (Mean ± SD) with 95% confidence interval (CI). The comprehensive effects of all treatments were ranked by the surface under the cumulative ranking (SUCRA) probabilities.

Results

Twenty-five studies involved 1,106 participants were included. Prebiotics were superior in decreasing Interleukin-6 (IL-6; SMD –0.74, 95% CI [–1.32, –0.16]) and tumor-necrosis factor-α (TNF-α; SMD –0.59, 95% CI [–1.09, –0.08]), synbiotics were more effective in declining C-reactive protein (CRP; SMD –0.69, 95% CI [–1.14, –0.24]) and endotoxin (SMD –0.83, 95% CI [–1.38, –0.27]). Regarding uremic toxins, prebiotics ranked highest in reducing indoxyl sulfate (IS; SMD –0.43, 95% CI [–0.81, –0.05]), blood urea nitrogen (BUN; SMD –0.42, 95% CI [–0.78, –0.06]), and malondialdehyde (MDA; SMD –1.88, 95% CI [–3.02, –0.75]). Probiotics were rated as best in alleviating GI symptoms (SMD: –0.52, 95% CI [–0.93, –0.1]).

Conclusion

Our research indicated prebiotics were more effective in declining IL-6, TNF-α, IS, MDA, and BUN, synbiotics lowering CRP and endotoxin significantly, and probiotics were beneficial for alleviating GI symptoms, which may contribute to better clinical decisions. This study was registered in PROSPERO (Number: CRD42021277056).

Systematic Review Registration

[http://www.crd.york.ac.uk/PROSPERO], identifier [CRD42021277056].

Synbiotics Easing Renal Failure by Improving Gut Microbiology II (SYNERGY II): A Feasibility Randomized Controlled Trial

Synbiotics have emerged as a therapeutic strategy for modulating the gut microbiome and targeting novel cardiovascular risk factors, including uremic toxins indoxyl sulfate (IS) and p-cresyl sulfate (PCS). This study aims to evaluate the feasibility of a trial of long-term synbiotic supplementation in adults with stage 3-4 chronic kidney disease (CKD). Adult participants with CKD and estimated glomerular filtration rate (eGFR) of 15-60 mL/min/1.73 m²) were recruited between April 2017 and August 2018 to a feasibility, double-blind, placebo-controlled, randomized trial of synbiotic therapy or matched identical placebo for 12 months. The primary outcomes were recruitment and retention rates as well as acceptability of the intervention. Secondary outcomes were treatment adherence and dietary intake. Exploratory outcomes were evaluation of the cardiovascular structure and function, serum IS and PCS, stool microbiota profile, kidney function, blood pressure, and lipid profile. Of 166 potentially eligible patients, 68 (41%) were recruited into the trial (synbiotic n = 35, placebo n = 33). Synbiotic and placebo groups had acceptable and comparable 12-month retention rates (80% versus 85%, respectively, p = 0.60). Synbiotic supplementation altered the stool microbiome with an enrichment of Bifidobacterium and Blautia spp., resulting in a 3.14 mL/min/1.73 m² (95% confidence interval (CI), -6.23 to -0.06 mL/min/1.73 m², p < 0.01) reduction in eGFR and a 20.8 µmol/L (95% CI, 2.97 to 38.5 µmol/L, p < 0.01) increase in serum creatinine concentration. No between-group differences were observed in any of the other secondary or exploratory outcomes. Long-term synbiotic supplementation was feasible and acceptable to patients with CKD, and it modified the gastrointestinal microbiome. However, the reduction in kidney function with synbiotics warrants further investigation.

Effect of synbiotic supplementation on asprosin level in high fat diet-induced metabolic disorder in pregnant rats

Synbiotic supplementation can improve metabolic disorders. The aim of this study was to assess the impact of synbiotic supplementation on the levels of asprosin, lipid profile, glucose, and insulin resistance in pregnant rats fed a high-fat diet (HFD). Rats were divided into three groups: control group (fed base chow), HFD group, and HFD + synbiotic group. Levels of blood glucose, total cholesterol, triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), insulin, and asprosin levels were measured. Birth weight of offspring in the HFD + synbiotic group was significantly lower than in the HFD group. Similarly, serum asprosin, insulin, insulin resistance, TG and total cholesterol levels in the HFD + symbiotic group were significantly lower than in the HFD group. Asprosin levels had a significant and positive correlation between food intake in the first ten days of the experiment and gestation period, fasting blood sugar (FBS), TG, and homeostatic model assessment (HOMA) index. Moreover, asprosin levels had a significant and negative correlation with HDL and insulin levels. Results showed, synbiotic supplementation has beneficial effects on obese animals and improves weight gain during pregnancy, pup birth weight, FBS, insulin resistance and lipid profile. These advantages of synbiotic supplementation could be mediated by reducing serum asprosin levels.

Effects of Probiotics, Prebiotics, and Synbiotics on Uremic Toxins, Inflammation, and Oxidative Stress in Hemodialysis Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The dysbiosis of gut microbiota may cause many complications in patients with end-stage renal disease, which may be alleviated by probiotic, prebiotic, and synbiotic supplementation. The aim of this systematic review and meta-analysis was to assess the effects of these supplementations on circulatory uremic toxins, biomarkers of inflammation, and oxidative stress in hemodialysis patients. We searched the EMBASE, MEDLINE, Web of Science, and Cochrane Library databases until 8 August 2021. Randomized controlled trials evaluating adult patients receiving hemodialysis were included. The pooled results from 23 studies with 931 hemodialysis patients indicated that interventions significantly decreased the circulating levels of p-cresyl sulfate (standardized mean difference (SMD): 0.38; 95% CI: -0.61, -0.15; p = 0.001), endotoxins (SMD: -0.58; 95% CI: -0.99, -0.18; p = 0.005), malondialdehyde (SMD: -1.16; 95% CI: -1.81, -0.52; p = 0.0004), C-reactive proteins (CRP) (SMD: -0.61; 95% CI: -0.99, -0.23; p = 0.002), and interleukin 6 (SMD: -0.92; 95% CI: -1.51, -0.33; p = 0.002), and improved the total antioxidant capacity (SMD: 0.89; 95% CI: 0.49, 1.30; p < 0.0001) and glutathione (SMD: 0.40; 95% CI: 0.14, 0.66; p = 0.003) when compared to the placebo group. Our results suggest that treatment with probiotics, prebiotics, and synbiotics may help alleviate uremic toxin levels, oxidative stress, and the inflammatory status in hemodialysis patients.

Redox biomarkers in dietary interventions and nutritional observation studies - From new insights to old problems

Purpose

The purpose of this review is to give an overview on recently published articles investigating the associations of diet and dietary interventions with biomarkers of oxidative stress with special emphasis on different categories of redox biomarkers.

Findings

Intervention and observational studies both in healthy participants and patients that investigated associations of dietary habits, foodstuffs or isolated nutrients with biomarkers of oxidative stress were included in this review. Recently published observation studies confirm the inverse association between fruit and vegetable intake and oxidative stress markers. Studies investigating the effect of vitamin D and vitamin E, magnesium, zinc, chromium, selenium, probiotic supplementation and several phytochemicals reported consistent changes in redox biomarkers. Of 88 articles included in this review, only seven studies measured biomarkers from the three categories: oxidative damage, endogenous antioxidants, and exogenous antioxidants. Many studies rely on controversial assays for total antioxidant capacity, thus there is potential in many studies to improve biomarker repertoire to cover all three categories of biomarkers and to turn away from such assays.

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Oxidative stress can be assessed by specific biomarker categories.

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Three biomarker categories: oxidative damage, endogenous, exogenous antioxidants.

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Only seven studies performed measurements of all three biomarker categories.

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TAC, TRAP, FRAP, ORAC should not be used as stand-alone redox marker.

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Several interventions reported improvements in markers of oxidative stress.

Effect of Probiotic, Prebiotic, and Synbiotic Supplementation on Cardiometabolic and Oxidative Stress Parameters in Patients With Chronic Kidney Disease: A Systematic Review and Meta-analysis

PURPOSE

Chronic kidney disease (CKD) is a major health problem worldwide. Evidence supporting the use of probiotic, prebiotic, and synbiotic supplementation in the management of CKD is mixed, although some studies suggest they may be useful. A systematic review and meta-analysis was performed to evaluate the effectiveness of probiotic, prebiotic, and synbiotic supplementation for improving cardiometabolic and oxidative stress parameters in patients with CKD.

METHODS

A comprehensive key word search was performed in EMBASE, Medline, Scopus, Cochrane Central, and Web of Science until April 2020. Randomized controlled trials investigating the effectiveness of probiotic, synbiotic, and prebiotic supplementation for the management of adults with CKD were included. Primary outcomes were measures of cardiometabolic parameters such as cholesterol and fasting blood glucose. Secondary outcomes were measures of oxidative stress (eg, malondialdehyde levels) and body mass index. Random effects meta-analyses were used to estimate mean treatment effects. Results are reported as standardized mean differences (SMDs) and 95% CIs.

FINDINGS

Fourteen articles were included. In patients with CKD, probiotic, prebiotic, and synbiotic supplementation significantly reduced total cholesterol (SMD, -0.25; 95% CI, -0.46 to -0.04; I² = 00.0%), fasting blood glucose (SMD, -0.41; 95% CI, -0.65 to -0.17; I² = 00.0%), homeostatic model assessment of insulin resistance (SMD, -0.63; 95% CI, -0.95 to -0.30; I² = 43.3%), insulin levels (SMD, -0.49; 95% CI, -0.90 to -0.08; I² = 65.2%), high-sensitivity C-reactive protein levels (SMD, -0.52; 95% CI, -0.81 to -0.22; I² = 52.7%), and malondialdehyde levels (SMD, -0.79; 95% CI, -1.22 to -0.37; I² = 69.8%) compared with control interventions. Supplementation significantly increased the quantitative insulin sensitivity check index (SMD, 0.78; 95% CI, 0.51 to 1.05; I² = 00.0%), total antioxidant capacity (SMD, 0.42; 95% CI, 0.18 to 0.66; I² = 00.0%), and glutathione levels (SMD, 0.52; 95% CI, 0.19 to 0.86; I² = 37.0%).

IMPLICATIONS

Probiotic, prebiotic, and synbiotic supplementation seems to be a promising intervention for improving cardiometabolic and oxidative stress parameters in patients with CKD.

Effect of probiotics on oxidative stress and inflammatory status in diabetic nephropathy: A systematic review and meta-analysis of clinical trials

This systematic review and meta-analysis was performed to evaluate the effect of probiotics on serum high sensitivity-C reactive protein (hs-CRP) and oxidative stress biomarkers among patients with Diabetic Nephropathy (DN). Electronic databases were searched through May 10, 2020. Seven trials that included 340 patients were identified for analysis. Meta-analysis indicated that probiotics significantly reduced hs-CRP (WMD = -1.53 mg/L; 95% CI = -2.38, -0.69; P < 0.001) and Malondialdehyde (MDA) (WMD = -0.62 ɥmol/L; 95% CI = -1.18, -0.06; P = 0.030) levels in DN patients, whereas they increased Glutathione (GSH) (WMD = 73.84 ɥmol/L; 95% CI = 24.3, 123.29; P = 0.003) and Total Antioxidant Capacity (TAC) (WMD = 26.54 mmol/L; 95% CI = 6.23, 46.85; P = 0.010). Therefore, probiotics may improve hs-CRP and oxidative stress biomarkers in DN population.

Probiotics, prebiotics, and synbiotics for the improvement of metabolic profiles in patients with chronic kidney disease: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to quantify the effects of probiotic, prebiotic, and synbiotic supplementation on biomarkers of inflammation and oxidative stress, as well as lipid profiles among patients with chronic kidney disease (CKD). Electronic databases, including PubMed, the Cochrane Database, and the Web of Science were searched from January 1, 2000, to May 15, 2019. All RCTs that investigated the effect of prebiotics, probiotics, and synbiotics on a circulating (serum and plasma) inflammatory marker (C-reactive protein [CRP]), oxidative stress indicators (malondialdehyde [MDA], glutathione [GSH], and total anti-oxidant capacity [TAC]); and lipid profiles (total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-c], and high-density lipoprotein cholesterol [HDL-c]) among patients with CKD were included. Data were pooled and expressed as a standardized mean difference (SMD) with a 95% confidence interval (CI). The protocol for this meta-analysis is registered with PROSPERO; No. CRD42019139090. Thirteen trials that included 671 patients were identified for analysis. The methodological quality varied across studies. Meta-analysis indicated that microbial therapies significantly reduced CRP (SMD, -0.75; 95% CI, -1.03 to -0.47; p = 0.000), MDA (SMD, -1.06; 95% CI, -1.59 to -0.52; p = 0.000), TC (SMD, -0.33; 95% CI, -0.52 to -0.13; p = 0.000), and LDL-c (SMD, -0.44; 95% CI, -0.86 to -0.02; p = 0.000) levels; they also increased the GSH (SMD, 0.44; 95% CI, 0.25 to 0.65; p = 0.000), TAC (SMD, 0.61; 95% CI, 0.07 to 1.15; p = 0.000), and HDL-c (SMD, 0.45; 95% CI, 0.03 to 0.87; p = 0.000) levels in CKD patients, as compared to the placebo groups; however, there was no statistically significant TG concentration among patients with CKD. Subgroup analyses showed that other key factors, such as the duration of intervention, participants' baseline body mass index (BMI), type of intervention, and age, had an effect of microbial therapies on outcomes. This meta-analysis supports the potential use of probiotic, prebiotic, and synbiotic supplements in the improvement of established biomarkers of inflammation and oxidative stress, as well as lipid profiles among patients with CKD, which are well-known cardiovascular risk factors. Further research into these interventions should consider the limitations of our study to explore the effect of long-term administration of these supplements in the CKD population.

The Efficacy of Prebiotic, Probiotic, and Synbiotic Supplementation in Modulating Gut-Derived Circulatory Particles Associated With Cardiovascular Disease in Individuals Receiving Dialysis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This systematic review and meta-analyses provide an up-to-date synthesis on the effects of supplementation on circulating levels of toxic metabolites, markers of uremia and inflammation, blood lipids, and other clinical outcomes.

METHODS

Seventeen databases were searched, supplemented with internet and hand searching. Randomized controlled trials of adult end-stage renal-disease individuals receiving either hemodialysis or peritoneal dialysis were eligible. Trials were restricted to those which had administered a prebiotic, probiotic, or synbiotic as an oral supplement. Primary outcomes were measures of circulating endotoxin, indoxyl-sulphate, and p-cresyl sulfate.

RESULTS

Twenty-one trials were eligible (1152 randomized participants), of which 16 trials were considered to have a high risk of bias. The number of trials available for meta-analysis varied for each primary outcome. Synthesized data indicated that supplementation significantly reduced circulating levels of endotoxin (standardized mean difference, -0.61; 95% confidence interval, -1.03 to -0.20; P = .004; I² = 0%), indoxyl-sulphate (-0.34; -0.64 to -0.04; P = .02; I² = 0%), and p-cresyl sulfate (-0.34; -0.61 to -0.07; P = .01; I² = 0%). For secondary outcomes, supplementation significantly reduced gastrointestinal symptoms (-0.54; -1.02 to -0.07; P = .02; I² = 0%).

CONCLUSIONS

Supplementation reduces toxic metabolites associated with cardiovascular disease and mortality in individuals receiving dialysis. However, the majority of trials included were low in quality.