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The Cochrane Database of Systematic... Oct 2023Chronic 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... (Review)
Review
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.
Topics: Adult; Child; Humans; Synbiotics; Prebiotics; Dysbiosis; Indican; Uremic Toxins; Renal Insufficiency, Chronic; Probiotics
PubMed: 37870148
DOI: 10.1002/14651858.CD013631.pub2 -
Advances in Nutrition (Bethesda, Md.) Nov 2023The COVID-19 pandemic highlighted the importance of healthy diets in the management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and... (Review)
Review
The COVID-19 pandemic highlighted the importance of healthy diets in the management of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19. Evidence suggests the influence of diet and dietary patterns during post-COVID-19, and the impact of the COVID-19 pandemic on dietary habits and quality. However, limited evidence lies on the association between a healthy diet, and risk of SARS-CoV-2 infection or COVID-19. This study aimed to conduct a systematic review of observational studies to examine the association between diet quality, and the risk of SARS-CoV-2 infection or COVID-19 among adult populations. 6158 research articles from Scopus, EMBASE, PubMed, and MEDLINE databases were identified for eligibility. Only observational studies were included. Study quality was assessed using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Thirteen studies were included (4 with SARS-CoV-2 infection and 9 with COVID-19 as the outcome); 3 were case-control, 3 were cross-sectional, and 7 were prospective studies. Adherence to Mediterranean diet was examined as exposure in 7 studies, and was associated with decreased risk of SARS-CoV-2 infection in 2 studies, with estimates varying from 12% to 22%, while COVID-19 risk or severity was found to be reduced in 3 studies with odds ratios (ORs) ranging from 36% to 77%. The Dietary Approaches to Stop Hypertension diet was inversely associated with COVID-19 hospitalization (OR: 0.19; 95% CI: 0.07, 0.55), whereas a healthy plant-based diet had an inverse association with both COVID-19 infection (hazard ratio [HR]: 0.91; 95% CI: 0.88, 0.94) and severity (HR: 0.59; 95% CI: 0.47, 0.74). Studies examining individual food groups generally found lower risk of infection or COVID-19 in association with larger dietary intakes of fruits, vegetables, and fiber. The overall findings of the observational studies in this review support the concept that nutritious diets might lower the risk of SARS-CoV-2 infection or COVID-19. This study was registered at PROSPERO as CRD42023397371.
Topics: United States; Adult; Humans; COVID-19; SARS-CoV-2; Pandemics; Prospective Studies; Diet, Healthy; Observational Studies as Topic
PubMed: 37748553
DOI: 10.1016/j.advnut.2023.09.006 -
International Archives of Allergy and... 2024This scoping review aims to critically assess gaps in the current literature on atopic dermatitis (AD) by evaluating the overall effectiveness of dietary interventions.... (Review)
Review
BACKGROUND
This scoping review aims to critically assess gaps in the current literature on atopic dermatitis (AD) by evaluating the overall effectiveness of dietary interventions. Through a comprehensive analysis that follows the Preferred Reporting Item for Systematic Review and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines, we conducted a thorough search on the Web of Science database in May 2023 using specific search strategies to identify all relevant studies on the research topic.
SUMMARY
A total of 104 full-text articles were included for review. Our synthesis identified seven notable categories of dietary interventions for AD, showcasing the diversity of interventions utilized. This includes vitamin supplementation, probiotic and prebiotic supplementation, dietary fat, biological compounds, foods from natural sources, major nutrients, and diet-related approaches. Further analyses stratified by targeted populations revealed a predominant focus on pediatrics, particularly in probiotic supplementation, and on adults, with an emphasis on vitamin D and E supplementation.
KEY MESSAGES
Despite most dietary interventions demonstrating overall effectiveness in improving AD severity and its subjective symptoms, several significant gaps were identified. There was a scarcity of studies on adults and whole-diet interventions, a prevalence of short-term interventions, heterogeneity in study outcomes, designs, and population, occasional disparity between statistical significance and clinical relevance, and a lack of a comprehensive multidisciplinary approach. Nonetheless, these findings offer valuable insights for future AD research, guiding additional evidence-driven dietary interventions and informing healthcare professionals, researchers, and individuals, advancing both understanding and management of AD.
Topics: Dermatitis, Atopic; Humans; Dietary Supplements; Probiotics; Diet; Prebiotics
PubMed: 38442688
DOI: 10.1159/000535903 -
Gut Microbes 2024Repeated exposure to antibiotics and changes in the diet and environment shift the gut microbial diversity and composition, making the host susceptible to pathogenic... (Meta-Analysis)
Meta-Analysis Review
Repeated exposure to antibiotics and changes in the diet and environment shift the gut microbial diversity and composition, making the host susceptible to pathogenic infection. The emergence and ongoing spread of AMR pathogens is a challenging public health issue. Recent evidence showed that probiotics and prebiotics may play a role in decolonizing drug-resistant pathogens by enhancing the colonization resistance in the gut. This review aims to analyze available evidence from human-controlled trials to determine the effect size of probiotic interventions in decolonizing AMR pathogenic bacteria from the gut. We further studied the effects of prebiotics in human and animal studies. PubMed, Embase, Web of Science, Scopus, and CINAHL were used to collect articles. The random-effects model meta-analysis was used to pool the data. GRADE Pro and Cochrane collaboration tools were used to assess the bias and quality of evidence. Out of 1395 citations, 29 RCTs were eligible, involving 2871 subjects who underwent either probiotics or placebo treatment to decolonize AMR pathogens. The persistence of pathogenic bacteria after treatment was 22%(probiotics) and 30.8%(placebo). The pooled odds ratio was 0.59(95% CI:0.43-0.81), favoring probiotics with moderate certainty ( = 0.0001) and low heterogeneity ( = 49.2%, = 0.0001). The funnel plot showed no asymmetry in the study distribution (Kendall'sTau = -1.06, = 0.445). In subgroup, showed the highest decolonization (82.4%) in probiotics group. -based probiotics and decolonize 71% and 77% of pathogens effectively. The types of probiotics ( < 0.018) and pathogens ( < 0.02) significantly moderate the outcome of decolonization, whereas the dosages and regions of the studies were insignificant ( < 0.05). Prebiotics reduced the pathogens from 30% to 80% of initial challenges. Moderate certainty of evidence suggests that probiotics and prebiotics may decolonize pathogens through modulation of gut diversity. However, more clinical outcomes are required on particular strains to confirm the decolonization of the pathogens. Protocol registration: PROSPERO (ID = CRD42021276045).
Topics: Probiotics; Humans; Prebiotics; Gastrointestinal Microbiome; Bacteria; Animals; Treatment Outcome; Anti-Bacterial Agents; Bacterial Infections; Gastrointestinal Tract
PubMed: 38778521
DOI: 10.1080/19490976.2024.2356279 -
Reviews in Endocrine & Metabolic... Feb 2024In recent years, a growing number of studies have examined the relationship between thyroid pathophysiology and intestinal microbiota composition. The reciprocal... (Review)
Review
In recent years, a growing number of studies have examined the relationship between thyroid pathophysiology and intestinal microbiota composition. The reciprocal influence between these two entities has been proven so extensive that some authors coined the term "gut-thyroid axis". However, since some papers reported conflicting results, several aspects of this correlation need to be clarified. This systematic review was conceived to achieve more robust information about: 1)the characteristics of gut microbiota composition in patients with the more common morphological, functional and autoimmune disorders of the thyroid; 2)the influence of gut microbial composition on micronutrients that are essential for the maintenance of thyroid homeostasis; 3)the effect of probiotics, prebiotics and synbiotics, some of the most popular over-the-counter products, on thyroid balance; 4)the opportunity to use specific dietary advice. The literature evaluation was made by three authors independently. A five steps strategy was a priori adopted. After duplicates removal, 1106 records were initially found and 38 reviews were finally included in the analysis. The systematic reviews of reviews found that: 1) some significant variations characterize the gut microbiota composition in patients with thyroid disorders. However, geographical clustering of most of the studies prevents drawing definitive conclusions on this topic; 2) the available knowledge about the effect of probiotics and synbiotics are not strong enough to suggest the routine use of these compounds in patients with thyroid disorders; 3) specific elimination nutrition should not be routine suggested to patients, which, instead have to be checked for possible micronutrients and vitamins deficiency, often owed to gastrointestinal autoimmune comorbidities.
Topics: Humans; Thyroid Gland; Prebiotics; Probiotics; Microbiota; Micronutrients
PubMed: 37824030
DOI: 10.1007/s11154-023-09839-9 -
Journal of Digestive Diseases Jan 2024Colorectal cancer (CRC) is highly prevalent worldwide and is a leading cause of cancer-related death. Probiotics, prebiotics, and synbiotics have recently attracted... (Meta-Analysis)
Meta-Analysis Review
Efficacy and safety of probiotics, prebiotics, and synbiotics for the prevention of colorectal cancer and precancerous lesion in high-risk populations: A systematic review and meta-analysis of randomized controlled trials.
OBJECTIVES
Colorectal cancer (CRC) is highly prevalent worldwide and is a leading cause of cancer-related death. Probiotics, prebiotics, and synbiotics have recently attracted attention as preventive measures against colorectal neoplasms. We aimed to analyze the findings of randomized controlled trials (RCTs) on the effects of probiotics, prebiotics, and synbiotics in patients at a high risk of CRC, outlining the challenges and future prospects of using probiotics to prevent colorectal tumors and providing evidence for clinical physicians in particular.
METHODS
PubMed, EMBASE, and the Cochrane Library databases were searched for relevant studies published up to January 7, 2022. RCTs conducted on populations with a high risk of CRC who received probiotics, prebiotics or synbiotics in comparison with placebo, candidate agent or no treatment were included. The primary outcome was the incidence or recurrence of any colorectal neoplasms. Additional outcomes included their effects on the diversity of gut microbiota and relevant inflammatory biomarkers. Safety outcomes were also analyzed. Two authors independently screened and selected studies based on pre-specified eligible criteria, performed data extraction and risk-of-bias assessment independently.
RESULTS
Nine RCTs were included in the systematic review and meta-analysis. Probiotic supplementation significantly reduced adenoma incidence, but no significant benefit was observed in CRC incidence. Additionally, probiotics modulated gut microbiota and inflammatory biomarkers.
CONCLUSION
Probiotics may have beneficial effects in the prevention of CRC. More RCTs with larger sample sizes are warranted to further confirm these findings.
Topics: Humans; Prebiotics; Synbiotics; Randomized Controlled Trials as Topic; Probiotics; Colorectal Neoplasms; Biomarkers; Precancerous Conditions
PubMed: 38126945
DOI: 10.1111/1751-2980.13247 -
Applied Microbiology and Biotechnology Apr 2024The importance of dietary fiber (DF) in animal diets is increasing with the advancement of nutritional research. DF is fermented by gut microbiota to produce... (Review)
Review
The importance of dietary fiber (DF) in animal diets is increasing with the advancement of nutritional research. DF is fermented by gut microbiota to produce metabolites, which are important in improving intestinal health. This review is a systematic review of DF in pig nutrition using in vitro and in vivo models. The fermentation characteristics of DF and the metabolic mechanisms of its metabolites were summarized in an in vitro model, and it was pointed out that SCFAs and gases are the important metabolites connecting DF, gut microbiota, and intestinal health, and they play a key role in intestinal health. At the same time, some information about host-microbe interactions could have been improved through traditional animal in vivo models, and the most direct feedback on nutrients was generated, confirming the beneficial effects of DF on sow reproductive performance, piglet intestinal health, and growing pork quality. Finally, the advantages and disadvantages of different fermentation models were compared. In future studies, it is necessary to flexibly combine in vivo and in vitro fermentation models to profoundly investigate the mechanism of DF on the organism in order to promote the development of precision nutrition tools and to provide a scientific basis for the in-depth and rational utilization of DF in animal husbandry. KEY POINTS: • The fermentation characteristics of dietary fiber in vitro models were reviewed. • Metabolic pathways of metabolites and their roles in the intestine were reviewed. • The role of dietary fiber in pigs at different stages was reviewed.
Topics: Animals; Dietary Fiber; Fermentation; Swine; Gastrointestinal Microbiome; Animal Feed; Animal Nutritional Physiological Phenomena; Fatty Acids, Volatile
PubMed: 38683435
DOI: 10.1007/s00253-024-13148-9 -
Nutrients Oct 2023Diabetes affects one in eleven adults globally, with rising cases in the past 30 years. Type 1 and type 2 cause blood sugar problems, increasing cardiovascular risks.... (Meta-Analysis)
Meta-Analysis Review
Diabetes affects one in eleven adults globally, with rising cases in the past 30 years. Type 1 and type 2 cause blood sugar problems, increasing cardiovascular risks. Dietary control, including chickpeas, is suggested but needs more research. Comprehensive searches were conducted across multiple databases for the randomized controlled trial efficacy of chickpea consumption to lower blood sugar levels to a healthy range, with data extraction and risk of bias assessment performed independently by two researchers. Statistical analysis was performed using RevMan 5.4, expressing continuous data as mean differences and risk ratios with 95% confidence intervals, and a summary of the findings is provided considering the variations in study characteristics. A total of 118 articles were initially identified from seven databases, primarily from Anglo-American countries, resulting in 12 selected studies after the identification and screening processes. These studies involved 182 participants, focusing on healthy or normoglycemic adults, and assessed the effects of chickpeas compared to various foods such as wheat, potatoes, pasta, sauce, cheese, rice, and corn. A meta-analysis involving a subset of studies demonstrated that chickpeas were more effective in reducing blood glucose iAUC compared to potatoes and wheat. Chickpeas offer the potential for blood sugar control through low starch digestibility, high fiber, protein, and hormonal effects. Although insulin benefits are seen, statistical significance varies, supporting their role in diabetic diets focusing on nutrient-rich foods over processed carbs.
Topics: Adult; Humans; Blood Glucose; Cicer; Randomized Controlled Trials as Topic; Diabetes Mellitus; Insulin
PubMed: 37960209
DOI: 10.3390/nu15214556 -
PloS One 2024Microbiome-directed therapies are increasingly utilized to optimize thyroid function in both healthy individuals and those with thyroid disorders. However, recent doubts... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Microbiome-directed therapies are increasingly utilized to optimize thyroid function in both healthy individuals and those with thyroid disorders. However, recent doubts have been raised regarding the efficacy of probiotics, prebiotics, and synbiotics in improving thyroid function. This systematic review aimed to investigate the potential relationship between probiotics/prebiotics and thyroid function by analyzing the impact on thyroid hormone levels.
METHODS
We conducted a comprehensive systematic review and meta-analysis of randomized controlled trials that investigated the effects of probiotics, prebiotics, and synbiotics on free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH), and thyroid stimulating hormone receptor antibody (TRAb) levels. We searched for articles from PubMed, Scopus, Web of Science, and Embase up until April 1st, 2023, without any language restriction. Quantitative data analysis was performed using a random-effects model, with standardized mean difference (SMD) and 95% confidence interval as summary statistics. The methods and results were reported according to the PRISMA2020 statement.
RESULTS
A total of eight articles were included in this review. The meta-analysis showed no significant alterations in TSH (SMD: -0.01, 95% CI: -0.21, 0.20, P = 0.93; I2: 0.00%), fT4 (SMD: 0.04, 95% CI: -0.29, 0.21, P = 0.73; I2: 0.00%) or fT3 (SMD: 0.45, 95% CI: -0.14, 1.03, P = 0.43; I2: 78.00%), while a significant reduction in TRAb levels was observed (SMD: -0.85, 95% CI: -1.54, -0.15, P = 0.02; I2: 18.00%) following probiotics/prebiotics supplementation. No indication of publication bias was found.
CONCLUSIONS
Probiotics/prebiotics supplementation does not influence thyroid hormone levels, but may modestly reduce TRAb levels in patients with Graves' disease.
Topics: Humans; Prebiotics; Probiotics; Randomized Controlled Trials as Topic; Synbiotics; Thyroid Gland; Thyroid Hormones; Thyrotropin
PubMed: 38206993
DOI: 10.1371/journal.pone.0296733 -
Cureus Mar 2024The GI tract hosts a dynamic community known as the gut microbiota, which encompasses thriving bacteria that actively contribute to the physiological functions of the... (Review)
Review
The GI tract hosts a dynamic community known as the gut microbiota, which encompasses thriving bacteria that actively contribute to the physiological functions of the human body. The intricacies of its composition are profoundly influenced by dietary preferences, where the quality, quantity, and frequency of food consumption play a pivotal role in either fostering or impeding specific bacterial strains. Type 2 diabetes mellitus (T2DM) is a prevalent and deleterious condition that originates from excessive hyperglycemia. Do lifestyle interventions targeting dietary adjustments, nutritional supplements, physical activity, and weight management programs exhibit a significant relationship in altering the composition of the gut microbiome and managing T2DM? This paper aims to evaluate the effects of lifestyle interventions on patients with T2DM and the implications of these changes on disease outcomes and progression. Lifestyle interventions can significantly impact the management of T2DM, especially those targeting dietary adjustments, nutritional supplements, physical activity, and weight management programs. The adoption of a high-fiber diet and increased fruit consumption have shown positive impacts on both insulin sensitivity and the composition of the gut microbiota. Additionally, promising outcomes emerge from supplementing with Omega-3 fatty acids, Vitamin K2 (MK-7), and transglucosidase, which influence insulin levels, glycemic control, and gut microbiota composition. Personalized diet interventions and the transformative effects of the Mediterranean diet present positive outcomes in metabolic control. The intensity of exercise plays a pivotal role in shaping the composition of the gut microbiota, with moderate-intensity continuous exercise displaying positive effects on anti-inflammatory microbes. Chronic exercise showcases favorable impacts on glycemic control and systemic inflammation. Emphasizing the intricate relationship between dietary habits, gut microbiota, and the risk of T2DM underscores the potential of the gut microbiota as a universal biomarker for assessing diabetes risk. Nutritional supplements and exercise interventions provide potential avenues for the management of T2DM, emphasizing the necessity for tailored strategies. Further research is encouraged to delve into the long-term effects and intricate interplay between lifestyle factors and the gut microbiome, enhancing our understanding of T2DM pathophysiology for targeted therapeutic approaches.
PubMed: 38646363
DOI: 10.7759/cureus.56737