Effect of symbiotic supplementation on glycemic control, lipid profiles and microalbuminuria in patients with non-obese type 2 diabetes: a randomized, double-blind, clinical trial

Probiotics and synbiotics for glycemic control in diabetes: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

The escalating prevalence of diabetes mellitus may benefit from add-on therapeutic approaches. Given the recognized need for an updated synthesis of the literature, this systematic review and meta-analysis aimed to synthesize and critically assess the available randomized controlled trials (RCTs) that investigate the efficacy of probiotics and synbiotics on glycemic control in patients with Type 1 (T1DM) and Type 2 (T2DM) diabetes mellitus.

METHODS

Comprehensive searches were conducted on PubMed, Embase, CINAHL, Scopus, and Web of Science, focusing on adults with T1DM or T2DM. All comparators were deemed eligible. Primary outcomes included changes in glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), and insulin levels. Only RCTs were included, and the Cochrane RoB2 tool assessed the risk of bias. Random-effect models facilitated data analysis, supplemented by sensitivity, subgroup analyses, and meta-regressions.

RESULTS

A total of 537 records were screened, resulting in 41 RCTs for analysis, which comprises 2991 (54% females) patients with diabetes. The meta-analysis revealed statistically significant improvements in HbA1c (standardized mean difference (SMD) = -0.282, 95% CI: [-0.37, -0.19], p < 0.001), FPG (SMD = -0.175, 95% CI: [-0.26, -0.09], p < 0.001), and insulin levels (SMD = -0.273, 95% CI: [-0.35, -0.20], p < 0.001). A medium degree of heterogeneity between studies was found in HbA1c (I2 = 62.5%), FPG (I2 = 71.5%), and insulin levels (I2 = 66.4%) analyses. Subgroup analyses indicated that the efficacy varied based on the type of strains used and the country. Multispecies strains were particularly effective in improving HbA1c levels.

CONCLUSION

The study findings suggest that probiotics and synbiotics may be effective as complementary therapies for managing diabetes. Additionally, the study underscores the need for further tailored research that considers variables such as strain types and geographical factors to deepen the understanding of the role of these interventions in diabetes care.

REVIEW REGISTRATION NUMBER

PROSPERO (CRD42023396348).

Microbiome-modulating nutraceuticals ameliorate dyslipidemia in type 2 diabetes: A systematic review, meta-analysis, and meta-regression of clinical trials

AIMS

Type 2 Diabetes is intrinsically linked to cardiovascular disease (CVD) via diabetic dyslipidemia, both of which remain global health concerns with annually increasing prevalence. Given the established links between gut microbiome dysbiosis and metabolic diseases, its modulation is an attractive target to ameliorate metabolic imbalances in such patients. There is a need to quantitively summarise, analyse, and describe future directions in this field.

METHODS

We conducted a systematic review, meta-analysis, and meta-regression following searches in major scientific databases for clinical trials investigating the effect of pro/pre/synbiotics on lipid profile published until April 2022. Data were pooled using random-effects meta-analysis and reported as mean differences with 95% confidence intervals (CIs). PROSPERO No. CRD42022348525.

RESULTS

Data from 47 trial comparisons across 42 studies (n = 2692) revealed that, compared to placebo/control groups, the administration of pro/pre/synbiotics was associated with statistically significant changes in total cholesterol (-9.97 mg/dL [95% CI: -15.08; -4.87], p < 0.0001), low-density lipoprotein (-6.29 mg/dL [95% CI: -9.25; -3.33], p < 0.0001), high-density lipoprotein (+3.21 mg/dL [95% CI: 2.20; 4.22], p < 0.0001), very-low-density lipoprotein (-4.52 mg/dL [95% CI: -6.36; -2.67], p < 0.0001) and triglyceride (-22.93 mg/dL [95% CI: -33.99; -11.87], p < 0.001). These results are influenced by patient characteristics such as age or baseline BMI, and intervention characteristics such as dosage and duration.

CONCLUSIONS

Our study shows that adjunct supplementation with a subset of pro/pre/synbiotics ameliorates dyslipidemia in diabetic individuals and has the potential to reduce CVD risk. However, widespread inter-study heterogeneity and the presence of several unknown confounders limit their adoption in clinical practice; future trials should be designed with these in mind.

Comparative efficacy and safety of probiotics, prebiotics, and synbiotics for type 2 diabetes management: A systematic review and network meta-analysis

AIMS

To compare the effects of probiotics, prebiotics, and synbiotics for type 2 diabetes (T2D) management.

METHODS

We searched PubMed, Scopus, CENTRAL, and grey literature sources to December 2022 for randomized trials of the impacts of probiotics, prebiotics, or synbiotics in patients with T2D. We performed network meta-analyses with a Bayesian framework to calculate mean difference [MD] and 95 % credible interval [CrI] and rated the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

68 randomised trials were included. All results are presented in comparison to the placebo. Supplementation with probiotics (MD: -0.25 %, 95%CrI: -0.42, -0.08; GRADE = moderate) and synbiotics (MD: -0.31 %, 95%CrI: -0.61, -0.04; GRADE = very low) resulted in a trivial/unimportant decrease in glycated hemoglobin. Supplementation with probiotics (MD: -0.69 mmol/L, 95%CrI: -0.98, -0.40; GRADE = very low) and synbiotics (MD: -0.82 mmol/L, 95%CrI: -1.22, -0.43; GRADE = very low) resulted in a trivial/unimportant decrease in fasting plasma glucose. Supplementation with probiotics resulted in a small but important decrease in low-density lipoprotein cholesterol (MD: -0.19 mmol/L; 95%CrI: -0.34, -0.05; GRADE = very low). Supplementations had moderate effects on serum triglyceride (GRADE = low).

CONCLUSIONS

Existing evidence is uncertain and does not support supplementation with probiotics, prebiotics, and synbiotics for T2D management.

Effects of prebiotics, probiotics and synbiotics on serum creatinine in non-dialysis patients: a meta-analysis of randomized controlled trials

OBJECTIVE

Serum creatinine level are influenced by many factors. Although accumulated data suggested that prebiotics, probiotics and synbiotics supplements could affect serum creatinine level, the results remained controversial. The aim of the present paper was to evaluate the effects of prebiotics, probiotics and synbiotics on serum creatinine in non-dialysis patients.

METHODS

PubMed, EMBASE (Excerpta Medica Database) and the Cochrane Library databases were searched for eligible randomized, controlled trials (RCTs) which were limited to English language studies until 30 September 2022. A random-effects model was performed to analyze the impact of pooled trials.

RESULT

Twelve randomized, controlled trial studies were included in the meta-analysis. Prebiotics, probiotics or synbiotics supplementation did not significantly decrease the serum creatinine levels in non-dialysis patients compared to placebo [standardized mean difference (SMD) = 0.05; 95% confidence interval (CI): (-0.21, 0.31); p = 0.72; I² = 61%].

CONCLUSION

The present meta-analysis indicated that supplementation with prebiotics, probiotics and synbiotics could not act as promising adjuvant therapies to decrease the serum creatinine levels in non-dialysis patients.

The Effect of Probiotic Supplements on Metabolic Parameters of People with Type 2 Diabetes in Greece-A Randomized, Double-Blind, Placebo-Controlled Study

The role of probiotic supplementation in type 2 diabetes (T2D) treatment is controversial. The present study aimed to assess the effects of a multi-strain probiotic supplement (LactoLevureR (containing Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium lactis, and Saccharomyces boulardii)) over 6 months, primarily on glycemic control as well as on lipid levels and alterations in the gut microbiome, among individuals with T2D residing in Greece. A total of 91 adults with T2D (mean age [±SD] 65.12 ± 10.92 years, 62.6% males) were randomized to receive the probiotic supplement or a matching placebo capsule, once daily, for 6 months. Blood chemistries and anthropometric parameters were conducted every 3 months, and stool samples were collected at baseline and at 6 months. Significant reductions in HbA1c, fasting blood glucose, and total cholesterol were observed in participants treated with the probiotic supplement (n = 46) compared to the controls (n = 45), even after adjustment for a greater decrease in adiposity (waist circumference). Although there were no statistically significant differences in the diversity of the gut microbiome (α and β diversity), the administration of probiotics did influence several genera, metabolites, and key enzymes associated with diabetes. Overall, the administration of the multi-strain probiotic LactoLevureR over a 6-month period in individuals with T2D was well-tolerated and had a positive impact on metabolic parameters, alongside improvements in indices of adiposity.

UTILITY OF STREM-1 BIOMARKER AND HCP GENE FOR IDENTIFICATION OF ACINETOBACTER BAUMANNII COLONIZATION AND INFECTION IN LUNG

ABSTRACT

Objective: Respiratory infections or colonization of Acinetobacter baumannii (Ab) are common in clinical practice but are treated differently. Early identification of Ab infection and colonization reduces the risk of antibiotic mismatch but objective laboratory indicators to distinguish between bacterial infections and colonization are lacking. To distinguish infection and colonization of Ab, we tested the role of two biomarkers, triggering receptor expressed on myeloid cells-1 (TREM-1) and hemolysin coregulated protein. Methods: A total of 96 inpatients with Ab were divided into infection and colonization groups. Blood samples were collected on days 1, 2, 3, 5, 8, and 10 and daily maximum body temperature was recorded. Polymerase Chain Reaction and Reverse Transcription Polymerase Chain Reaction were used to detect the presence and expression levels of the hcp gene in Ab clinical isolates. Results : sTREM-1 and procalcitonin (PCT) levels on days 1 to 10 and neutrophil classification (N%) on days 1 to 3 were different ( P < 0.05) in the infection group and colonization group. Receiver operating characteristic (ROC) curves showed significant differences in N% and sTREM-1 on days 2 and 3 ( P < 0.01). sTREM-1 had the highest AUC ROC on days 1, 2, and 3 of all the markers. On day 1, the ROC curve of "WBC&N%&PCT&sTREM-1" was statistically different from individual indices (white blood cell count, N%, and PCT; P < 0.05) and was equal to the ROC curve of sTREM-1 ( P > 0.05). Thirty five of 96 patients were classified as infection group and 61 as colonization group with hcp gene detection rates of 71.43% (25/35) and 31.15% (19/61), respectively. No differences in hcp gene presence and transcript levels were found between two groups ( P > 0.05). Conclusions: Dynamic monitoring of sTREM-1 and PCT is valuable in identifying Ab infection and colonization. sTREM-1 can be improved by combination with multiple biomarkers in the early stage for identification of infection and colonization. The hcp gene was more likely to be present in the infection cohort.

The Effect of Probiotic Supplementation on Glucolipid Metabolism in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

PURPOSE

Type 2 diabetes mellitus (T2DM) is a persistent metabolic condition with an unknown pathophysiology. Moreover, T2DM remains a serious health risk despite advances in medication and preventive care. Randomised controlled trials (RCTs) have provided evidence that probiotics may have positive effects on glucolipid metabolism. Therefore, we performed a meta-analysis of RCTs to measure the effect of probiotic therapy on glucolipid metabolism in patients with T2DM.

METHODS

With no constraints on the language used in the literature, Excerpta Medica Database, PubMed, the Cochrane Library, and the Web of Science were searched for pertinent RCTs published between the date of creation and 18 August 2022. Stringent inclusion and exclusion criteria were applied by two reviewers to independently examine the literature. The risk of bias associated with the inclusion of the original studies was assessed using the Cochrane risk-of-bias tool, and Stata 15.0 was used to perform the meta-analysis.

RESULTS

Thirty-seven publications containing a total of 2502 research participants were included in the meta-analysis. The results showed that after a probiotic intervention, the experimental group showed a significant decrease in body mass index (standardised mean difference (SMD) = -0.42, 95% confidence interval (CI) [-0.76, -0.08]), fasting glucose concentration (SMD = -0.73, 95% CI [-0.97, -0.48]), fasting insulin concentration (SMD = -0.67, 95% CI [-0.99, -0.36]), glycated haemoglobin concentration (SMD = -0.55, 95% CI [-0.75, -0.35]), Homeostatic Model Assessment for Insulin Resistance score (SMD = -0.88, 95% CI [-1.17, -0.59]), triglyceride concentration (SMD = -0.30, 95% CI [-0.43, -0.17]), total cholesterol concentration (SMD = -0.27, 95% CI [-0.43, -0.11]), and low-density lipoprotein concentration (SMD = -0.20, 95% CI [-0.37, -0.04]), and an increase in high-density lipoprotein concentration (SMD = 0.31, 95% CI [0.08, 0.54]). Moreover, subgroup analyses showed that patients with a longer intervention time, or those who were treated with multiple strains of probiotics, may benefit more than those with a shorter intervention time or those who were treated with a single probiotic strain, respectively.

CONCLUSION

Probiotic supplementation improves glucolipid metabolism in patients with T2DM, offering an alternative approach for the treatment of these patients.

Short chain fatty acids and GIT hormones mitigate gut barrier disruption in high fat diet fed rats supplemented by synbiotics

High fat diet (HFD) predisposes to many metabolic changes; it may disrupt gut barrier integrity and gut microbiota composition. Synbiotic supplementation may promote host’s metabolic health by selective activation of the healthy microorganisms. This study aimed to probe the interaction between synbiotic supplementation, gut microbiota and gut hormones in HFD states. Twenty-seven adult male albino rats, 3 groups, group I: control, group II: HFD received HFD for 12 weeks and group III: synbiotic-supplemented HFD received synbiotic in the last 6 weeks. The anthropometric measurments were measured. Liver transaminases, lipid profile, parameters of insulin resistance, serum serotonin, glucagon like polypeptide-1 (GLP-1), oxidant/antioxidant markers (MDA/GPx), zonulin levels and quantitative cecal short chain fatty acids (SCFA) were assessed. Samples of liver and colon were employed for histopathological studies. Compared to HFD group, synbiotic led to a significant reduction in anthropometric measurements, liver enzymes, atherogenic index, HOMA-IR and MDA denoting improved dyslipidemia, insulin resistance and oxidative state. Moreover, synbiotic supplementation decreased serum zonulin and increased both serum serotonin, GLP-1 and cecal SCFAs. Synbiotic supplementation ameliorated the metabolic derangements and the disturbed integrity of the intestinal barrier induced by HFD. As synbiotics can increase gut hormones (serum GLP-1&serotonin) and SCFAs.

Manipulating the Gut Microbiome as a Therapeutic Strategy to Mitigate Late Effects in Childhood Cancer Survivors

Recent studies have identified causal links between altered gut microbiome, chronic inflammation, and inflammation-driven conditions such as diabetes and cardiovascular disease. Childhood cancer survivors (CCS) show late effects of therapy in the form of inflammaging-related disorders as well as microbial dysbiosis, supporting a hypothesis that the conditions are interconnected. Given the susceptibility of the gut microbiome to alteration, a number of therapeutic interventions have been investigated for the treatment of inflammatory conditions, though not within the context of cancer survivorship in children and adolescents. Here, we evaluate the potential for these interventions, which include probiotic supplementation, prebiotics/fiber-rich diet, exercise, and fecal microbiota transplantation for prevention and treatment of cancer treatment-related microbial dysbiosis in survivors. We also make recommendations to improve adherence and encourage long-term lifestyle changes for maintenance of healthy gut microbiome in CCS as a potential strategy to mitigate treatment-related late effects.

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.

Effects of probiotic/prebiotic/synbiotic supplementation on blood glucose profiles: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

Previous studies have evaluated the effects of probiotic/prebiotic/synbiotic supplementation on blood glucose profiles among diabetic patients. However, the results were inconsistent.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic searching from PubMed, ISI Web of Science, Embase, and Cochrane Central was conducted to identify high-quality clinical trials investigating the effect of probiotic/prebiotic/synbiotic supplementation on blood glucose profiles [including fasting blood glucose (FBG), hemoglobin A1c (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR)] up to December 2020. Subgroup analyses by types or durations of probiotic/prebiotic/synbiotic supplementation were conducted to investigate the different effects among different populations.

RESULTS

A total of 39 trials with 3517 participants were included in the final analyses. Among patients with type II diabetes (T2DM), the summarized standardized mean differences (SMDs) and 95% confidential intervals (95% CIs) of FBG, HbA1c, and HOMA-IR were -0.30 (95% CI: -0.65 to 0.05), -0.59 (95% CI: -0.88 to -0.30), and -0.68 (95% CI: -1.13 to -0.23), respectively. Among patients with gestational diabetes (GDM), the summary SMDs of FBG, HbA1c and HOMA-IR were -0.67 (95% CI: -1.23 to -0.11), -0.24 (95% CI: -0.57 to 0.08), and -1.06 (95% CI: -1.72 to -0.40), respectively. Similar improvements in blood glucose profiles were also found among persons with prediabetes or gestational woman with normal glucose, but not among patients with type I diabetes. Subgroup analyses showed similar results of probiotic supplementation for patients with T2DM and probiotic/synbiotic supplementation for patients with GDM.

CONCLUSION

Probiotic/prebiotic/synbiotic supplementation might improve the blood glucose profiles among patients with T2DM/GDM, persons with prediabetes, or gestational woman with normal glucose. Trials with more sophisticated design are needed to validate the results in the future.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020161975.

The effect of probiotics/synbiotics supplementation on renal and liver biomarkers in patients with type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials

Despite the apparent beneficial effects of probiotics/synbiotics on glucose haemostasis, lipid profile and inflammatory responses, it is not clear whether these beneficial effects also impact renal and hepatic function in diabetes. Therefore, we sought to assess the effect of probiotics/synbiotics supplementation on renal and liver biomarkers in adults with type 2 diabetes mellitus (T2DM) using a systematic review and meta-analysis of randomised controlled trials (RCT). PubMed, Scopus, Web of Science and Cochrane Library were systematically searched, up to February 2021. The pooled weighted mean difference (WMD) was estimated using a random-effects model. The methodological quality of studies, as well as certainty of evidence, was assessed using standard scales. Fifteen related trials were identified. Meta-analysis of six trials, involving 426 participants, indicated that probiotics/synbiotics supplementation reduced serum levels of creatinine (WMD = -0·10 mg/dl, 95 % CI -0·20, -0·00; P = 0·01; I ² = 87·7 %; P-heterogeneity < 0·001), without any significant effect on blood urea nitrogen (BUN), glomerular filtration rate or microalbuminuria. No significant improvement was found on liver biomarkers following probiotics/synbiotics supplementation. The subgroup analysis showed a significant improvement in BUN when follow-up duration lasted for 12 weeks or more (WMD = -1·215 mg/dl, 95 % CI -1·933, -0·496; P = 0·001) and in creatinine levels in patients with renal dysfunction (WMD = -0·209 mg/dl, 95 % CI -0·322, -0·096; P < 0·001). Our results are insufficient to advocate the use of probiotics/synbiotics for improving renal or liver function in patients with T2DM. Indeed, due to the low certainty of evidence, these findings need to be affirmed in further high-quality RCT.

Probiotics and Synbiotics Supplementation Improve Glycemic Control Parameters in Subjects with Prediabetes and Type 2 Diabetes Mellitus: A GRADE-assessed systematic review, meta-analysis, and meta-regression of randomized clinical trials

Probiotics and synbiotics have been proposed to exhibit an important role in glucose homeostasis and maintain the balance of the gut microbiota. However, clinical trials have shown mixed findings. Therefore, we conducted a systematic review and meta-analysis of all eligible randomized controlled trials (RCTs) examining the effects of probiotics and synbiotics intake on glycemic outcomes among individuals with prediabetes and type 2 diabetes mellitus (T2DM). The PubMed/Medline, Scopus, ISI Web of Science, and Cochrane library were searched up to March 2022 for published RCTs exploring the effectiveness of probiotics and synbiotics compared to control on glycemic outcomes. The random-effects model was applied in order to the estimation of 95% confidence interval (CI) and the weighted mean difference (WMD) for each endpoint. Meta-analysis of forty-six RCTs (3067 participants) showed that probiotics and synbiotics supplementation significantly reduced fasting plasma glucose (FPG) (weighted mean difference (WMD): -11.18mg/dl, 95% CI: -13.60, -8.75, p ˂0.001), fasting insulin serum level (WMD: -1.23 µIU/ml, 95% CI: -1.76, -0.71, p ˂0.001), hemoglobin A1c (HbA1c) (WMD: -0.35%, 95% CI: -0.44, -0.26, p˂0.001), and homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: -0.87, 95% CI: -1.09, -0.65, p˂0.001). Additionally, probiotics and synbiotics intake resulted in an increase in values of quantitative insulin-sensitivity check index (QUICKI) (WMD: 0.01, 95% CI: 0.00, 0.01, p˂0.001). However, probiotics and synbiotics consumption did not change glucose values following oral glucose tolerance test (OGTT). Our findings suggest that probiotic and synbiotic intake has favorable effects on glycemic profile in patients with prediabetes and T2DM.

The impact of prebiotic fructooligosaccharides on gut dysbiosis and inflammation in obesity and diabetes related kidney disease

Obesity is an extensive health problem worldwide that is frequently associated with diabetes. It is a risk factor for the development of several diseases including diabetic nephropathy. Recent studies have reported that gut dysbiosis aggravates the progression of obesity and diabetes by increasing the production of uremic toxins in conjunction with gut barrier dysfunction which then leads to increased passage of lipopolysaccharides (LPS) into the blood circulatory system eventually causing systemic inflammation. Therefore, the modification of gut microbiota using a prebiotic supplement may assist in the restoration of gut barrier function and reduce any disturbance of the inflammatory response. In this review information has been compiled concerning the possible mechanisms involved in an increase in obesity, diabetes and kidney dysfunction via the exacerbation of the inflammatory response and its association with gut dysbiosis. In addition, the role of fructooligosaccharides (FOS), a source of prebiotic widely available commercially, on the improvement of gut dysbiosis and attenuation of inflammation on obese and diabetic conditions has been reviewed. The evidence confirms that FOS supplementation could improve the pathological changes associated with obesity and diabetes related kidney disease, however, knowledge concerning the mechanisms involved is still limited and needs further elucidation.

The Relationships between Gut Microbiota and Diabetes Mellitus, and Treatments for Diabetes Mellitus

Diabetes mellitus is considered to be a global epidemic. The combination of genetic susceptibility and an unhealthy lifestyle is considered to be the main trigger of this metabolic disorder. Recently, there has been increased interest in the roles of gut microbiota as a new potential contributor to this epidemic. Research, in recent years, has contributed to an in-depth characterization of the human microbiome and its associations with various diseases, including metabolic diseases and diabetes mellitus. It is known that diet can change the composition of gut microbiota, but it is unclear how this, in turn, may influence metabolism. The main objective of this review is to evaluate the pathogenetic association between microbiota and diabetes and to explore any new therapeutic agents, including nutraceuticals that may modulate the microbiota. We also look at several mechanisms involved in this process. There is a clear, bidirectional relationship between microbiota and diabetes. Current treatments for diabetes influence microbiota in various ways, some beneficial, but others with still unclear effects. Microbiota-aimed treatments have seen no real-world significant effects on the progression of diabetes and its complications, with more studies needed in order to find a really beneficial agent.

Effects of Oligosaccharides on Markers of Glycemic: Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE To Investigate the effect of oligosaccharide on marker of glycemic including fasting blood glucose (FBG), fasting blood insulin (FBI), glycated hemoglobin (HbA1c), homeostasis model assessment of insulin resistance (HOMA-IR),...

Meta-analysis of randomized controlled trials of the effects of probiotics on type 2 diabetes in adults

BACKGROUND & AIMS

Despite advancements in preventive medicine and pharmacotherapy, diabetes remains an overwhelming health problem. Evidence from randomized controlled trials (RCTs) suggests that probiotics may offer beneficial effects on glycemic control. Our objective was to perform a systematic review and meta-analysis of RCTs to quantify the effect of probiotic administration on glycemic homeostasis in type 2 diabetes.

METHODS

Medline, Web of Science, Google Scholar, and Cochrane Central Register of Controlled Trials were searched for relevant trials published until October 12, 2021. RCTs that lasted ≥3 weeks and assessed the effects of probiotics on the markers of glycemic homeostasis in type 2 diabetes were included. Data were pooled using the generic inverse variance method and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed using Cochran's Q statistic and quantified using the I² statistic. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the certainty of evidence.

RESULTS

A total of 33 eligible trial comparisons (n = 1927) were included in this meta-analysis. Our results revealed that compared with placebo, a median probiotic dose of ∼10⁹ cfu/day significantly reduced the glycated hemoglobin (HbA_1c) levels (MD: -0.19% [95% CI: -0.32, -0.07]; P = 0.003), fasting blood glucose levels (MD: -1.00 mmol/L [95% CI: -1.45, -0.56]; P < 0.0001), fasting insulin levels (MD: -5.73 pmol/L [95% CI: -12.17, 0.72]; P = 0.08), and HOMA-insulin resistance (IR) (MD: -1.00 [95% CI: -1.32, -0.68]; P < 0.00001). The certainty of evidence was graded low for HbA_1c and fasting glucose, moderate for fasting insulin, and high for HOMA-IR. Probiotic supplements do not induce clinically significant reductions in HbA_1c levels, but lead to marginally clinically significant reductions in fasting glucose and fasting insulin levels in patients with type 2 diabetes. Compared with single-strain and low-dose probiotics, multi-strain and high-dose probiotics have a greater beneficial effect on glycemic homeostasis. In addition, probiotic treatment may be more effective in patients with a high baseline body mass index and age.

Effect of Probiotic Supplementation on Glycemic Outcomes in Patients with Abnormal Glucose Metabolism: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

The effectiveness of probiotics in patients with abnormal glucose metabolism has not been clearly demonstrated. It is also unclear if outcomes are consistent across different probiotic formulations.

METHODS

A literature search was conducted using PubMed, EMBASE, and Cochrane CENTRAL database from inception through May 2020. Randomized controlled trials that evaluated the effect of probiotics on fasting blood glucose (FBG) or hemoglobin A1c (HbA1c) in patients with prediabetes, type 2 diabetes mellitus, or gestational diabetes were included. Outcomes of interest included FBG, HbA1c, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-B), and quantitative insulin sensitivity check index (QUICKI). Weighted mean difference (WMD) and 95% confidence intervals (CIs) were calculated using the DerSimonian and Laird random-effects model.

RESULTS

31 studies involving 1,948 participants were included in this analysis. Compared to control, probiotics had a significant favorable effect on FBG (WMD -5.77 mg/dL, 95% CI -8.48 to -3.06), HbA1c (WMD -0.32%, 95% CI -0.47 to -0.18), fasting insulin (WMD -2.95 µIU/mL, 95% CI -3.76 to -2.14), HOMA-IR (WMD -0.82, 95% CI -1.05 to -0.59), HOMA-B (WMD -14.86, 95% CI -24.57 to -5.16), and QUICKI (WMD 0.015, 95% CI 0.011-0.019). Further, probiotics were associated with favorable outcomes on all parameters at doses between 1 and 10 × 109 colony-forming unit per day (p < 0.004 for all) and formulations containing 2-4 strains (p < 0.05 for all).

DISCUSSION/CONCLUSION

Probiotics appear to have a modest effect on glycemic parameters in patients with abnormal glucose metabolism. Due to the limited number of trials conducted in patients with prediabetes, more studies are warranted in this population.

Effects and Mechanisms of Probiotics, Prebiotics, Synbiotics, and Postbiotics on Metabolic Diseases Targeting Gut Microbiota: A Narrative Review

Metabolic diseases are serious threats to public health and related to gut microbiota. Probiotics, prebiotics, synbiotics, and postbiotics (PPSP) are powerful regulators of gut microbiota, thus possessing prospects for preventing metabolic diseases. Therefore, the effects and mechanisms of PPSP on metabolic diseases targeting gut microbiota are worth discussing and clarifying. Generally, PPSP benefit metabolic diseases management, especially obesity and type 2 diabetes mellitus. The underlying gut microbial-related mechanisms are mainly the modulation of gut microbiota composition, regulation of gut microbial metabolites, and improvement of intestinal barrier function. Moreover, clinical trials showed the benefits of PPSP on patients with metabolic diseases, while the clinical strategies for gestational diabetes mellitus, optimal formula of synbiotics and health benefits of postbiotics need further study. This review fully summarizes the relationship between probiotics, prebiotics, synbiotics, postbiotics, and metabolic diseases, presents promising results and the one in dispute, and especially attention is paid to illustrates potential mechanisms and clinical effects, which could contribute to the next research and development of PPSP.

Effectiveness and safety of Bifidobacterium and berberine in human hyperglycemia and their regulatory effect on the gut microbiota: a multi-center, double-blind, randomized, parallel-controlled study

BACKGROUND

Berberine and Bifidobacterium have been reported to improve glucose tolerance in people with hyperglycemia or other metabolic disorders. This study aimed to assess the hypoglycemic effect and the regulation of the gut microbiota caused by berberine and Bifidobacterium and the possible additive benefits of their combination.

METHODS

This was an 18-week, multi-center, randomized, double-blind, parallel-controlled study of patients newly diagnosed with hyperglycemia. After a 2-week run-in period, 300 participants were randomly assigned to the following four groups for 16 weeks of treatment: berberine (Be), Bifidobacterium (Bi), berberine and Bifidobacterium (BB), and placebo group. The primary efficacy endpoint was the absolute value of fasting plasma glucose (FPG) compared with baseline after 16 weeks of treatment.

RESULTS

Between October 2015 and April 2018, a total of 297 participants were included in the primary analysis. Significant reductions of FPG were observed in the Be and BB groups compared with the placebo group, with a least square (LS) mean difference of - 0.50, 95% CI [- 0.85, - 0.15] mmol/L, and - 0.55, 95% CI [- 0.91, - 0.20] mmol/L, respectively. The Be and BB groups also showed significant reductions in 2-h postprandial plasma glucose. A pronounced decrease in HbA1c occurred in the BB group compared to the placebo group. Moreover, compared with the Bi and placebo groups, the Be and BB groups had more changes in the gut microbiota from the baseline.

CONCLUSIONS

Berberine could regulate the structure and function of the human gut microbiota, and Bifidobacterium has the potential to enhance the hypoglycemic effect of berberine. These findings provide new insights into the hypoglycemic potential of berberine and Bifidobacterium.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT03330184. Retrospectively registered on 18 October 2017.

Manipulation of intestinal microbiome as potential treatment for insulin resistance and type 2 diabetes

PURPOSE

Increasing evidence suggests that the intestinal microbiome (IM) and bacterial metabolites may influence glucose homeostasis, energy expenditure and the intestinal barrier integrity and lead to the presence of systemic low-grade inflammation, all of which can contribute to insulin resistance (IR) and type 2 diabetes (T2D). The purpose of this review is to explore the role of the IM and bacterial metabolites in the pathogenesis and treatment of these conditions.

RESULTS

This review summarizes research focused on how to modulate the IM through diet, prebiotics, probiotics, synbiotics and fecal microbiota transplant in order to treat IR and T2D.

CONCLUSION

There is an abundance of evidence suggesting a role for IM in the pathogenesis of IR and T2D based on reviewed studies using various methods to modulate IM and metabolites. However, the results are inconsistent. Future research should further assess this relationship.

The beneficial effects of the composite probiotics from camel milk on glucose and lipid metabolism, liver and renal function and gut microbiota in db/db mice

Background

Probiotics may have beneficial effects on patients with type 2 diabetes mellitus (T2DM). We separated 4 lactobacillus and 1 saccharomycetes from traditional fermented cheese whey (TFCW) and prepared composite probiotics from camel milk (CPCM) and investigated their effects on glucose and lipid metabolism, liver and renal function and gut microbiota in db/db mice.

Methods

CPCM was prepared in the laboratory and 40 db/db mice were randomly divided into 4 groups as metformin, low-dose and high-dose group and model group, and treated for 6 weeks. In addition, 10 C57BL/Ks mice as normal control group were used for comparison. Fasting blood glucose (FBG), body weight (BW), oral glucose tolerance test (OGTT), glycated hemoglobin (HbAlc), C-peptide (CP), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), 24 h urinary microalbumin (24 h malb), urine ketone, urine sugar, pancreas and liver tissue and intestinal flora were tested.

Results

Compared to diabetic group, high dose CPCM significantly decreased FBG, OGTT, HbAlc and IRI, plasma TC, TG, LDL-C, 24 h malb, urine ketone and urine sugar, increased CP, HDL-C levels, improved the liver and kidney function, protected the function of islets, also increased intestinal tract lactic acid bacteria and Bifidobacterium, decreased Escherichia in db/db mice.

Conclusion

CPCM decreased FBG, OGTT and HbAlc, increased CP, modulated lipid metabolism and improved liver and kidney protected injury in db/db mice, which may be related to various probiotics acting through protecting the function of islets and regulating intestinal flora disturbance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03303-4.

Diabetes and the Gut Microbiome

Gut dysbiosis in diabetes mellitus is associated with decreased short-chain fatty acids and epithelial barrier disruption. Microbial-derived toxins move across the "leaky gut" and incur systemic inflammation and insulin resistance. In children, gut dysbiosis has been associated with risk of developing type 1 diabetes mellitus. In animal models, the obesity phenotype is transferable via microbiota transplantation. Plant-based low protein diets and certain anti-diabetic drugs have been associated with positive microbiome effects. Clinical trials with prebiotics and probiotics have yielded mixed results. Further investigations are needed to evaluate the gut microbiome as a potential therapeutic target for diabetes prevention and management.

The effect of probiotics, prebiotics or synbiotics on metabolic outcomes in individuals with diabetes: a systematic review and meta-analysis

AIMS/HYPOTHESIS

The aim was to conduct a systematic review and meta-analysis of randomised controlled clinical trials assessing the effect of probiotic, prebiotic or synbiotic supplementation on gut microbiota and glucose control and lipid levels in individuals with diabetes.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched. The eligibility criteria for the studies was involvement of participants with a diagnosis of type 1 or type 2 diabetes. Metabolic outcomes (glucose control, insulinaemia, and lipid profile) of any probiotic, prebiotic or synbiotic supplementation related to modification of gut microbiota (prebiotics, probiotics and synbiotics) were analysed. We provided a narrative synthesis and meta-analysis of the findings on metabolic outcomes from the studies. Metabolic outcomes were extracted post-intervention and expressed as mean differences (MDs) and 95% CIs between treatment and comparator groups. We pooled the results using a random-effects meta-analysis. The meta-analysis was conducted using Review Manager (RevMan) software.

RESULTS

After the removal of duplicates and ineligible studies, 5219 studies were retained for review of titles and abstracts. The number of articles was reduced to 130 by review, for which the full-text articles were obtained and reassessed, 38 of which were included in the final meta-analysis. Overall, the use of prebiotics, probiotics or synbiotics reduced HbA_1c levels, but did not reach the threshold for significance (-2.17 mmol/mol, 95% CI -4.37, 0.03; p = 0.05, [-0.20%, 95% CI -0.40 to 0.00; p = 0.05, I² = 66%]) and had no effect on LDL-cholesterol levels (-0.05 mmol/l; 95% CI -0.14, 0.05, p = 0.35, I² = 37%). However, their consumption decreased levels of fasting blood glucose (-0.58 mmol/l; 95% CI -0.86, -0.30; p < 0.01, I² = 60%), total cholesterol (-0.14 mmol/l; 95% CI -0.26, -0.02, p = 0.02, I² = 39%), triacylglycerols (-0.11 mmol/l; 95% CI -0.20, -0.02, p = 0.01, I²= 21%) and insulinaemia (-10.51 pmol/l; 95% CI -16.68,-4.33, p < 0.01, I² = 74%), and increased HDL-cholesterol levels (0.04 mmol/l; 95% CI 0.01, 0.07, p < 0.01, I²= 24%).

CONCLUSIONS/INTERPRETATION

In individuals with diabetes mellitus, supplementation with probiotics, prebiotics or synbiotics improved metabolic variables, although the magnitude of this effect is low. Our results suggest that consumption of probiotics, prebiotics or synbiotics may be a potential adjuvant treatment for improving metabolic outcomes.

REGISTRATION

PROSPERO ID CRD42017080071. Graphical abstract.

Effects of Probiotic Supplementation on Dyslipidemia in Type 2 Diabetes Mellitus: A Meta-Analysis of Randomized Controlled Trials

The effectiveness of probiotic consumption in controlling dyslipidemia in type 2 diabetes mellitus (T2DM) has been unclear. We reviewed relevant randomized controlled trials (RCTs) to clarify the effect of probiotic intake on dyslipidemia in T2DM patients. The Web of Science, Scopus, PubMed and Cochrane Library databases were used for searching relevant RCTs published up to October 2020. The total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) concentrations were selected as the primary indicators for dyslipidemia. The results of 13 eligible RCTs showed that probiotic intake could significantly reduce TC (SMD: −0.23, 95% CI: (−0.37, −0.10)) and TG (SMD: −0.27, 95% CI: (−0.44, −0.11)) levels, but did not regulate LDL-C or HDL-C concentrations. Subgroup analysis showed that multispecies probiotics (≥two species), but not single-species probiotics, significantly decreased TC and TG concentrations. Furthermore, powder, but not liquid, probiotics could reduce TC and TG concentrations. This meta-analysis demonstrated that probiotic supplementation is helpful in reducing TC and TG concentrations in T2DM patients. However, more well-controlled trials are needed to clarify the benefits of probiotics on dyslipidemia in T2DM patients.

Microbiota and Diabetes Mellitus: Role of Lipid Mediators

Diabetes Mellitus (DM) is an inflammatory clinical entity with different mechanisms involved in its physiopathology. Among these, the dysfunction of the gut microbiota stands out. Currently, it is understood that lipid products derived from the gut microbiota are capable of interacting with cells from the immune system and have an immunomodulatory effect. In the presence of dysbiosis, the concentration of lipopolysaccharides (LPS) increases, favoring damage to the intestinal barrier. Furthermore, a pro-inflammatory environment prevails, and a state of insulin resistance and hyperglycemia is present. Conversely, during eubiosis, the production of short-chain fatty acids (SCFA) is fundamental for the maintenance of the integrity of the intestinal barrier as well as for immunogenic tolerance and appetite/satiety perception, leading to a protective effect. Additionally, it has been demonstrated that alterations or dysregulation of the gut microbiota can be reversed by modifying the eating habits of the patients or with the administration of prebiotics, probiotics, and symbiotics. Similarly, different studies have demonstrated that drugs like Metformin are capable of modifying the composition of the gut microbiota, promoting changes in the biosynthesis of LPS, and the metabolism of SCFA.

Efficacy of Probiotics in Patients of Cardiovascular Disease Risk: a Systematic Review and Meta-analysis

This meta-analysis examined the effect of probiotics on outcomes associated with cardiovascular disease risk factors (high blood pressure, overweight BMI, high cholesterol and triglycerides, elevated HbA1c and serum glucose). All randomised controlled trials publish on PubMed, Scopus, Embase, Grey Literature and the Cochrane Central Register of Controlled Trials (CENTRAL) from 1990 to 2020 were systematically searched. The PEDro scale was used to assess the quality of studies. A total of 34 studies with 2177 adults were selected for inclusion in the analysis. The mean difference and effect size with a 95% confidence interval (CI) were analysed for the pooled results. Statistically significant pooled effects of probiotics were found in the reduction of systolic and diastolic blood pressure, total cholesterol, LDL-C, serum glucose, HbA1C and BMI; and elevation of HDL-C. No significant changes were observed in the outcome of triglycerides. Subgroup analysis revealed statistically significant effects of probiotics on the treatment of risk factors, with results favouring longer duration of treatment (> 1.5 months), use of alternate formulations (kefir and powder), higher dosage of probiotics (> 1.0 × 10⁹ CFU), lower rate of study attrition (< 15%), double blinding of the study, diabetic patients and female populations. In summary, our meta-analysis showed a highly significant reduction in SBP, DBP associated with type 2 diabetes and in patients with diabetes mellitus, milk intake and more than 1.5 months duration intake. The effect on the reduction of total cholesterol LDL-C was associated with diabetes, hypertension, hypercholesterolemia, yoghurt intake and less than 1.5 months probiotic intake. The effect on the reduction of glucose and HbA1c was associated with diabetes, small dosage of probiotics, milk type and less than 1.5 months duration intake. Additionally, probiotic supplement had a beneficial effect in reducing BMI associated with obesity, higher dosage intake of probiotics and more than 1.5 months duration of intake.

The consequences of altered microbiota in immune-related chronic kidney disease

The normal gut microbiome modulates host enterocyte metabolism and shapes local and systemic immunity. Accumulation of urea and other waste products in chronic kidney disease induces gut dysbiosis and intestinal wall inflammation (leaky gut). There are decreased numbers of bacteria that generate short-chain fatty acids, which are an important nutrient source for host enterocytes and also contribute to regulation of the host immune system. Anaerobic proteolytic bacteria that express urease, uricase and indole and p-cresol enzymes, such as Enterobacteria and Enterococci, are increased. Microbial-derived uremic toxins such as indoxyl sulfate and trimethylamine N-oxide contribute to the pathophysiology of immune-related kidney diseases such as diabetic nephropathy, lupus nephritis and immunoglobulin A (IgA) nephropathy. Animal and clinical studies suggest potential benefits of dietary and probiotic interventions in slowing the progression of immune-related kidney diseases.

The effect of synbiotics supplementation on anthropometric indicators and lipid profiles in women with polycystic ovary syndrome: a randomized controlled trial

Background

Different therapies have been suggested for polycystic ovary syndrome (PCOS), but changes in lifestyle and diet have been considered. Diet and dietary factors can be very effective in modifying the disease. The positive effects of probiotic and synbiotics supplementation on improving lipid profiles and anthropometric indices have been examined in various diseases. This study was conducted to evaluate the effects of synbiotics supplementation on lipid and anthropometric profiles in infertile women with PCOS.

Methods

PCOS patients aged 19–37 years old were randomized to receive either synbiotics supplement (n = 50) or placebo (n = 49) for 12 weeks.

Results

Consumption of synbiotics compared to the placebo, resulted in a significant decrease in Low-density lipoprotein cholesterol (LDL) value (Change Mean Difference (CMD): 4.66, 95%CI: 0.20, 9.13) and a significant increase in high-density lipoprotein cholesterol (HDL) (CMD: 1.80, 95%CI: 0.34, 3.26). Although we failed to find a significant effect of synbiotics consumption on total cholesterol (TC) and triglyceride (TG) levels. We did not find differences in anthropometric indices between groups.

Conclusions

Overall, 12 weeks of synbiotics supplementation among PCOS women resulted in beneficial effects on LDL and HDL, although it is not yet clear how much our findings are clinically significant and more clinical studies with larger sample sizes are still needed.

Trial registration

Iranian Registry of clinical Trial, IRCT.ir, ID: IRCT2014110515536N2. Registered on 19 December 2015.

Graphical abstract

The Effects of Synbiotic Supplementation on Glycemic Status, Lipid Profile, and Biomarkers of Oxidative Stress in Type 1 Diabetic Patients. A Placebo-Controlled, Double-Blind, Randomized Clinical Trial

BACKGROUND AND OBJECTIVE

The aim of the present study was to evaluate the effects of synbiotic on glycemic status, lipid profile, and biomarkers of oxidative stress in type 1 diabetes mellitus (T1DM) patients.

MATERIALS AND METHODS

In this double-blind clinical trial, 50 T1DM patients were randomly allocated to intervention (n = 25) and control (n = 25) groups and received either synbiotic powder (Lactobacillus sporogenes GBI-30 (probiotic), maltodextrin and fructooligosaccharide (prebiotic)) or placebo 2 g per day for 8 weeks. Fasting blood samples were collected before and after the intervention to measure fasting blood glucose (FBG), insulin concentration, hemoglobin A1c (HbA1c), lipid profile, and biomarkers of oxidative stress such as total antioxidant capacity (TAC) and hs-C-reactive protein (hs-CRP).

RESULTS

Supplementation with synbiotic resulted in a significant decrease in the mean serum levels of HbA1c and hs-CRP (p = 0.01 and p = 0.004, respectively), and marginally significant decrease in FBG (p = 0.05) in the intervention group post- intervention. Also, the mean changes of FBG and hs-CRP were significantly lower in the intervention group compared with the control group (p = 0.03 and p = 0.005, respectively). There were no significant changes found in lipid profile in intervention group post-intervention (p≥ 0.05). The mean serum levels of insulin and TAC were significantly increased in the intervention group post-intervention (p = 0.001). There was a significant increase in the mean changes of TAC (p = 0.005) in the intervention group compared with the control group.

CONCLUSION

The 8-week synbiotic supplementation in T1DM patients may be effective in improvement of FBG, HbA1c, insulin, hs-CRP, and TAC.

Do Probiotics Improve the Health Status of Individuals with Diabetes Mellitus? A Review on Outcomes of Clinical Trials

Probiotics are now considered as an adjuvant and complementary therapeutic agent for several health complications, especially for metabolic and gastrointestinal disorders because of the influential impact of probiotic consumption on gut microbiota and immunity. Diabetes mellitus (DM) is fourth, in noncommunicable disease category, leading cause of mortality, morbidity, and economic crises in the world. Though several progressions are added in the medical field in recent decades, the treatment and management of diabetic-related health issues are still challenging. The present study summarizes the effects of probiotic supplementation on the health status of diabetic patients. The relevant information was collected from Scopus, PubMed, and Google Scholar. The detailed literature survey revealed that the consumption of probiotic supplementation significantly improved the overall health condition of diabetic patients. Especially, the probiotic intervention improved the fasting blood glucose, insulin sensitivity, and systemic inflammatory and antioxidant status in type 2 diabetic (T2D) patients. Moreover, improvement of gut microbial composition and prevention of bacterial translocation has also been observed in probiotic-supplemented T2D people. Some of the studies evidenced that the supplementation of probiotics can prevent and improve the gestational DM. Nevertheless, some of the studies reported negative results and limitations in the results of clinical trials. However, further studies are mandatory to develop a concrete probiotic-based adjuvant treatment procedure to treat DM.

A Mini-Review of Human Studies on Cholesterol-Lowering Properties of Probiotics

Cardiovascular diseases (CVD) are the major health issue of modernized society with a high mortality rate. Lifestyle, genetic makeup, and diet are some of the major influencing factors associated with CVD. The dyslipidemia is one such factor related to the development of several CVD. Many studies proved that the consumption of probiotics confers several health benefits. Several studies reported the evaluation of the cholesterol-lowering ability of probiotics (probiotics that showed positive effect in vitro and in vivo studies) in human volunteers. The current review summarizes the outcomes of human studies on the cholesterol-lowering property of probiotics. Probiotic consumption significantly improved the health status of hypercholesteremic patients by reducing the low-density lipoprotein cholesterol, total cholesterol, triglyceride levels, and increased the high-density lipoprotein cholesterol. The probiotic supplementation improved the lipid profile of diabetic patients, and obese people as well. However, not all probiotic interventions are effective against dyslipidemia. The results are controversial and depend on several factors such as probiotic strain, dose, duration of the treatment, lifestyle changes, etc. This literature survey indorses additional studies on the cholesterol-lowering property of probiotics, which could help to reduce the risk of CVD and other dyslipidemia associated health issues.

Impact of bacterial probiotics on obesity, diabetes and non-alcoholic fatty liver disease related variables: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To systematically review the effect of oral intake of bacterial probiotics on 15 variables related to obesity, diabetes and non-alcoholic fatty liver disease.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, EMBASE and COCHRANE from 1990 to June 2018.

ELIGIBILITY CRITERIA

Randomised controlled trials (≥14 days) excluding hypercholesterolaemia, alcoholic liver disease, polycystic ovary syndrome and children <3 years.

RESULTS

One hundred and five articles met inclusion criteria, representing 6826 subjects. In overweight but not obese subjects, probiotics induced improvements in: body weight (k=25 trials, d=-0.94 kg mean difference, 95% CI -1.17 to -0.70, I²=0.0%), body mass index (k=32, d=-0.55 kg/m², 95% CI -0.86 to -0.23, I²=91.9%), waist circumference (k=13, d=-1.31 cm, 95% CI -1.79 to -0.83, I²=14.5%), body fat mass (k=11, d=-0.96 kg, 95% CI -1.21 to -0.71, I²=0.0%) and visceral adipose tissue mass (k=5, d=-6.30 cm², 95% CI -9.05 to -3.56, I²=0.0%). In type 2 diabetics, probiotics reduced fasting glucose (k=19, d=-0.66 mmol/L, 95% CI -1.00 to -0.31, I²=27.7%), glycated haemoglobin (k=13, d=-0.28 pp, 95% CI -0.46 to -0.11, I²=54.1%), insulin (k=13, d=-1.66 mU/L, 95% CI -2.70 to -0.61, I²=37.8%) and homeostatic model of insulin resistance (k=10, d=-1.05 pp, 95% CI -1.48 to -0.61, I²=18.2%). In subjects with fatty liver diseases, probiotics reduced alanine (k=12, d=-10.2 U/L, 95% CI -14.3 to -6.0, I²=93.50%) and aspartate aminotransferases (k=10, d=-9.9 U/L, 95% CI -14.1 to -5.8, I²=96.1%). These improvements were mostly observed with bifidobacteria (Bifidobacterium breve, B. longum), Streptococcus salivarius subsp. thermophilus and lactobacilli (Lactobacillus acidophilus, L. casei, L. delbrueckii) containing mixtures and influenced by trials conducted in one country.

CONCLUSIONS

The intake of probiotics resulted in minor but consistent improvements in several metabolic risk factors in subjects with metabolic diseases.

TRIAL REGISTRATION NUMBER

CRD42016033273.

Intestinal Barrier Function-Non-alcoholic Fatty Liver Disease Interactions and Possible Role of Gut Microbiota

Non-alcoholic fatty liver disease (NAFLD) is a metabolic stress liver injury that is closely related to obesity, insulin resistance, type 2 diabetes, atherosclerosis, and metabolic syndrome. The pathological features are diffuse hepatic vesicular steatosis, including non-alcoholic steatohepatitis, liver fibrosis, and even liver cancer. A variety of pathological outcomes cause serious harm to human health. At present, an increasing number of researchers are investigating the pathogenesis of NAFLD from the perspective of changes in the function of the intestinal barrier. The physical, chemical, immunological, and microbiological barriers in the intestinal tract constitute the complete intestinal barrier, which plays an important defensive role against the invasion of harmful substances from the intestines. Protecting the function of the intestinal barrier is a new way to treat NAFLD and its related diseases. In this perspective, we summarized the current knowledge of the role of the intestinal barrier in NAFLD.

Efficacy of synbiotic supplementation in obesity treatment: A systematic review and meta-analysis of clinical trials

Several investigations have been reported the beneficial effects of synbiotic in participants with obesity, but these findings have been inconsistent. Therefore, we systematically reviewed available randomized clinical trials (RCTs) to elucidate the overall effects of synbiotic supplementation on anthropometric indices among participants with overweight or obesity. Five electronic databases including PubMed, Scopus, ISI Web of science, Cochrane Library and Google Scholar were searched up to October 2018. All RCTs using synbiotic supplements to treat obesity included in this systematic review and meta-analysis. Weighted mean difference (WMD) was pooled using a random-effects model. The present meta-analysis of 23 randomized trials indicated that supplementation with synbiotic can decrease body weight (WMD: -0.80 kg; 95% CI: -1.56 to -0.03, p = 0.04) and WC (WMD: -2.07 cm; 95% CI: -3.11 to -1.03, p < 0.001). In contrast, synbiotic did not have favorite effects on BMI (WMD: -0.12 kg/m²; 95% CI: -0.40 to 0.16, p = 0.39) and body fat (WMD: 0.02%; 95% CI: -1.27 to 1.87, p = 0.74) compared with the placebo group. Meta-regression analyses revealed that the dosage of probiotic did not have any effect on anthropometric measures. Based on our findings, modulation of gut microbiota composition through synbiotic supplementation might have modest effects on body weight and waist circumference. In this field, however, our knowledge is progressing.

Effects of Prebiotic and Synbiotic Supplementation on Glycaemia and Lipid Profile in Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials

Purpose: Diabetes Mellitus (T2DM) as a chronic disease, is on rise in parallel with other non-communicable diseases. Several studies have shown that probiotics and prebiotics might exert beneficial effects in chronic diseases including diabetes. Because of controversial results from different trials, the present study aims to assess the effects of prebiotic/synbiotic consumption on metabolic parameters in patients with type2 diabetes. Methods: A systematic literature search was performed on randomized controlled trial published in PubMed/Medline, SciVerse Scopus, Google scholar, SID and Magiran up to March 2018. Of a total number of 255 studies found in initial literature search, ten randomized controlled trials were included in the meta-analysis. The pooled mean net change were calculated in fasting blood-glucose [FBG], Hemoglobin A1c [HbA1c] and lipid markers (total cholesterol [TC], triglyceride [TG], low-density lipoprotein cholesterol [LDL-C], high density lipoprotein cholesterol [HDL-C]). The meta-analyses was conducted using Revman Software (v5.3). Results: The pooled estimate indicated a significant difference for the mean change in FBG, HbA1c and HDL in treatment group in comparison with control group. Subgroup analysis by intervention showed a significant difference in TG, LDL and HDL (synbiotic group) and in TG, TC, FBG, HDL and HbA1c (prebiotic group) compared with placebo. In another subgroup analysis, high quality studies showed significant reductions in TG, TC, FBG and HbA1c in intervention group compared with placebo group. Conclusion: In summary, diets supplemented with either prebiotics or synbiotics can result in improvements in lipid metabolism and glucose homeostasis in type 2 diabetic patients.