Probiotics Contribute to Glycemic Control in Patients with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis

Effects of probiotics supplementation on glycemic profile in adults with type 2 diabetes mellitus: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Disturbed glycemia and the resulting type 2 diabetes (T2D) are significant health concerns. Various approaches have been examined to improve glycemic control in patients with T2D. Modification of gut microbiome via administering probiotics has been extensively studied. The present study aims to sum up the existing literature which investigated the effect of probiotics on glycemic indices in individuals with T2D in the format of randomized controlled trials (RCTs).

METHODS

Online medical databases (PubMed, Scopus, and Web of Science) were searched from inception to January 2024. Eligible studies were included using pre-defined inclusion and exclusion criteria. Outcome variables included fasting blood sugar (FBS), insulin, hemoglobin A1c (HbA1c), and homeostatic model of insulin resistance (HOMA-IR). Weighted mean differences (WMDs) were estimated. Subgroup and dose-response analyses were conducted. P-values <0.05 were considered as statistically significant.

RESULTS

Out of 5636 records retrieved by the initial search, thirty-two RCTs were included in the final analyses. Supplementation with probiotics was observed to significantly improve indices of glycemic control; including FBS (WMD: -13.27 mg/dl; 95 % CI: -18.31, -8.22), HbA1c (WMD: -0.44 %; 95 % CI: -0.59, -0.28), insulin (WMD: -1.33 μIU/ml; 95 % CI: -2.57, -0.08), and HOMA-IR (WMD: -0.95; 95 % CI: -1.71, -0.18). Dose-response analysis revealed that increased duration of intervention results in a larger reduction only in FBS.

CONCLUSION

Supplementation with probiotics seems to improve indices of glycemic control. Nonetheless, taken into account the notable heterogeneity (with regard to dosage, duration, and the species/strains used) between the included studies and low quality of evidence, caution must be considered, especially when long-term clinical implications are intended.

The effect of microbiome-modulating therapeutics on glucose homeostasis in metabolic syndrome: A systematic review, meta-analysis, and meta-regression of clinical trials

BACKGROUND

Metabolic syndrome (MetS) is a chronic disorder featuring overweight/obesity, high blood pressure, and dysfunction of lipid and carbohydrate metabolism. Microbiome-modulating probiotics, prebiotics, synbiotics and fecal microbiota transplant (FMT) are promising adjunct therapies for improving parameters of glucose homeostasis and insulinemia.

METHODS

We conducted a comprehensive systematic review, meta-analyses, and meta-regressions to investigate the effect of the abovementioned microbiome therapies on various biomarkers after screening clinical trials published through April 2023. We pooled data using random effects meta-analyses, reporting them as mean differences (MDs) with 95 % confidence intervals (CIs), and conducting univariate linear model meta-regressions.

RESULTS

Data from 21 trial comparisons across 19 studies (n = 911) revealed that, compared to placebo/control, microbiome-modulating therapies were associated with statistically significant changes in fasting plasma glucose (MD: 4.03 mg/dL [95%CI: 6.93; -1.13]; p effect = 0.006, I2 = 89.8 %), and fasting insulin (MD: 2.56 μU/mL [95%CI: 4.28; -0.84]; p effect = 0.004, I2 = 87.9 %), but not insulin resistance or sensitivity indices and HbA1c. Age, baseline BMI, baseline biomarker value, pro/synbiotic dosage, trial duration, nutraceutical type, and WHO region were factors affecting the efficacy of these interventions at producing changes in biomarkers, signaling the potential role of personalized precision medicine adjunct therapy for deranged glucose homeostasis in patients with MetS. Nevertheless, presence of heterogeneity calls for further investigation before their clinical application.

CONCLUSIONS

Probiotics, prebiotics, synbiotics and FMT supplementation improved fasting glucose and insulin in patients with MetS. Further large-scale and high-quality trials are required before potential clinical applications.

Gut microbiota interventions in type 2 diabetes mellitus: An umbrella review of glycemic indices

BACKGROUND

We aimed to explore how probiotics, prebiotics, or synbiotics impact glycemic indices in patients with diabetes mellitus.

METHOD

A comprehensive search was conducted on PubMed, Scopus, and Web of Science from inception up to April 2023. The random-effects model was employed for the study analysis. Furthermore, sensitivity and subgroup analyses were conducted to investigate potential sources of heterogeneity. AMSTAR2 checklist was used to determine the quality of studies. Comprehensive meta-analysis version 3 was used for the study analysis.

RESULT

A total of 31 studies were included in the final analysis. Based on the results of the meta-analysis, gut microbial therapy could significantly decrease serum fasting blood glucose levels in patients with type 2 diabetes mellitus (effect size: -0.211; 95 % CI: -0.257, -0.164; P < 0.001). Additionally, significant associations were also found between gut microbial therapy and improved serum levels of fasting insulin, glycated hemoglobin, and homeostatic model assessment for insulin resistance (effect size: -0.087; 95 % confidence interval: -0.120, -0.053; P < 0.001; effect size: -0.166; 95 % confidence interval: -0.200, -0.132; P < 0.001; effect size: -0.230; 95 % confidence interval: -0.288, -0.172; P < 0.001, respectively).

CONCLUSION

Our results revealed promising effects of gut microbiota modulation on glycemic profile of patients with type 2 diabetes mellitus. The use of these agents as additional treatments can be considered.

The Role of Fecal Microbiota Transplantation (FMT) in the Management of Metabolic Diseases in Humans: A Narrative Review

The gut microbiota represents a complex ecosystem of trillions of microorganisms residing in the human gastrointestinal tract, which is known to interact with the host physiology and regulate multiple functions. Alterations in gut microbial composition, diversity, and function are referred to as dysbiosis. Dysbiosis has been associated with a variety of chronic diseases, including Clostridioides difficile infections, but also cardiometabolic diseases, including obesity, metabolic syndrome, and type 2 diabetes mellitus (T2DM). The implication of gut microbiota dysbiosis in the pathogenesis of both obesity and T2DM has paved the way to implementing novel therapeutic approaches for metabolic diseases through gut microbial reconfiguration. These interventions include probiotics, prebiotics, and synbiotics, while a more innovative approach has been fecal microbiota transplantation (FMT). FMT is a procedure that delivers healthy human donor stool to another individual through the gastrointestinal tract, aiming to restore gut microbiota balance. Several studies have investigated this approach as a potential tool to mitigate the adverse metabolic effects of gut microbiota aberrations associated with obesity and T2DM. The aim of the present review was to critically summarize the existing evidence regarding the clinical applications of FMT in the management of obesity and T2DM and provide an update on the potential of this method to remodel the entire host microbiota, leading thus to weight loss and sustained metabolic benefits. Safety issues, long-term efficacy, limitations, and pitfalls associated with FMT studies are further discussed, emphasizing the need for further research and standardization in certain methodological aspects in order to optimize metabolic outcomes.

The predicted mechanisms and evidence of probiotics on type 2 diabetes mellitus (T2DM)

Type 2 diabetes mellitus (T2DM) is a serious endocrine and metabolic disease that is highly prevalent and causes high mortality and morbidity rates worldwide. This review aims to focus on the potential of probiotics in the management of T2DM and its complications and to summarise the various mechanisms of action of probiotics with respect to T2DM. In this review, experimental studies conducted between 2016 and 2022 were explored. The possible mechanisms of action are based on their ability to modulate the gut microbiota, boost the production of short-chain fatty acids (SCFAs) and glucagon-like peptides, inhibit α-glucosidase, elevate sirtuin 1 (SIRT1) levels while reducing fetuin-A levels, and regulate the level of inflammatory cytokines. This review recommends carrying out further studies, especially human trials, to provide robust evidence-based knowledge on the use of probiotics for the treatment of T2DM.IMPACT STATEMENTT2DM is prevalent worldwide causing high rates of morbidity and mortality.Gut microbiota play a significant role in the pathogenesis of T2DM.Probiotics can be used as possible therapeutic tools for the management of T2DM.The possible mechanisms of action of probiotics include modulation of the gut microbiota, production of SCFAs and glucagon-like peptides, inhibition of α-glucosidase, raising SIRT1, reducing fetuin-A levels, and regulating the level of inflammatory cytokines.

Effect of a Nurse-Led Exercise Program on Depression in Elderly Patients with Diabetes: A Retrospective Study

BACKGROUND

Patients with diabetes often face psychological challenges, particularly depression. The coexistence of these two conditions can significantly impact both the mental and physical health of individuals. This study aims to investigate the effects of nurse-led exercise training on elderly patients diagnosed with type 2 diabetes mellitus and comorbid depression through experimental research. By selecting appropriate exercise programs for patients, the study seeks to identify effective strategies for improving both their physical health and depressive symptoms. Additionally, it aims to offer tailored exercise recommendations to enhance the overall well-being of these patients.

METHOD

The observation group (n = 53) and the control group (n = 53) were selected based on the interventions documented in the patients' medical records, with eligible patients identified as research participants. The control group received standard medication, while the observation group engaged in intensive exercise training in addition to their standard treatment, dedicating 60-90 min per day to exercise. Prior to and following the intervention, blood glucose indices, levels of 5-hydroxytryptamine (5-HT) and norepinephrine (NE), self-rating depression scale (SDS), Self-Rating Anxiety Scale (SAS), Pittsburgh Sleep Quality Index (PSQI), and Generic Quality of Life Inventory (GQOLI-74) scores were assessed to evaluate the impact of the exercise training intervention.

RESULT

Following the intervention, levels of fasting blood glucose (FBG), 2-h postprandial blood glucose (PBG), and Hemoglobin A1c (HbA1c) were reduced compared to pre-intervention levels, with the exercise group exhibiting lower levels than the control group (p < 0.05). Additionally, post-intervention, patients' levels of 5-HT and NE increased, with the exercise group demonstrating higher levels than the control group (p < 0.05). Moreover, post-intervention, SDS and SAS scores decreased, with more significant improvements observed in the observation group (p < 0.05). Furthermore, the intervention improved sleep quality and quality of life among patients in the exercise group compared to those in the control group (p < 0.05).

CONCLUSION

Nurse-guided exercise training demonstrates a significant capacity to ameliorate glycemic indexes among patients with diabetes mellitus comorbid with depression. It not only diminishes depression and anxiety levels but also enhances the expression of 5-HT and NE. Furthermore, it effectively elevates patients' sleep quality and quality of life. These findings underscore the potential of nurse-led exercise interventions for clinical promotion and widespread application.

Effect of probiotics at different intervention time on glycemic control in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Background

Type 2 diabetes mellitus(T2DM) is characterized by hyperglycemia. Gut microbiome adjustment plays a positive part in glucose regulation, which has become a hotspot. Probiotics have been studied for their potential to control the gut flora and to treat T2DM. However, the conclusion of its glucose-lowering effect is inconsistent based on different probiotic intervention times.

Objectives

To comprehensively evaluate how various probiotic intervention times affect glycemic control in people with T2DM.

Methods

We retrieved PubMed, Embase, Web of Science, and Cochrane Library on randomized controlled trials(RCTs)regarding the impact of probiotics on glycemic control in patients with T2DM from the inception to November 16, 2023. Separately, two researchers conducted a literature analysis, data extraction, and bias risk assessment of the involved studies. We followed the PRISMA guidelines, used RevMan 5.4 software for meta-analysis, and assessed the risk of bias by applying the Cochrane Handbook for Systematic Reviews 5.1.0.

Results

We included eight RCTs with 507 patients. Meta-analysis revealed that the use of probiotics might considerably reduce levels of glycosylated hemoglobin (HbA1c) {mean deviation (MD) = -0.33, 95% confidence interval (CI) (-0.59, -0.07), p = 0.01}, Insulin {standard mean deviation (SMD) = -0.48, 95% CI (-0.74, -0.22), p = 0.0003} and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR){SMD = -1.36, 95% CI (-2.30, -0.41), p = 0.005} than placebo group. No statistically significant differences were found regarding fasting blood glucose (FBG) and body mass index (BMI) {SMD = -0.39, 95% CI (-0.83, 0.05), p = 0.08}, {SMD = -0.40, 95% CI (-1.07, 0.27), p = 0.25}, respectively. Subgroup analyses, grouped by intervention times, showed that six to eight weeks of intervention improved HbA1c compared to the control group (p < 0.05), both six to eight weeks and 12-24 weeks had a better intervention effect on Insulin, and HOMA-IR (p < 0.05).In contrast, there was no statistically significant variation in the length between FBG and BMI regarding duration.

Conclusion

This meta-analysis found probiotics at different intervention times play a positive role in modulating glucose in T2DM, specifically for HbA1c in six to eight weeks, Insulin and HOMA-IR in six to eight weeks, and 12-24 weeks. To confirm our findings, further excellent large-sample research is still required.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023483325.

Gut Microbiota and Metabolic Syndrome: Relationships and Opportunities for New Therapeutic Strategies

Since its discovery, numerous studies have shown the role of the microbiota in well-being and disease. The gut microbiota represents an essential factor that plays a multidirectional role that affects not just the gut but also other parts of the body, including the brain, endocrine system, humoral system, immune system, and metabolic pathways, as well as host-microbiome interactions. Through a comprehensive analysis of existing literature using the desktop research methodology, this review elucidates the mechanisms by which gut microbiota dysbiosis contributes to metabolic dysfunction, including obesity, dyslipidaemia, hypertension, atherosclerosis, hyperuricemia, and hyperglycaemia. Furthermore, it examines the bidirectional communication pathways between gut microbiota and host metabolism, highlighting the role of microbial-derived metabolites, immune modulation, and gut barrier integrity in shaping metabolic homeostasis. Importantly, the review identifies promising therapeutic strategies targeting the gut microbiota as potential interventions for metabolic syndrome, including probiotics, prebiotics, symbiotics, dietary modifications, and faecal microbiota transplantation. By delineating the bidirectional interactions between gut microbiota and metabolic syndrome, the review not only advances our understanding of disease pathophysiology but also underscores the potential for innovative microbiota-based interventions to mitigate the global burden of metabolic syndrome and its associated complications.

A, Sarma DK, Verma V, Nagpal R, Mohania D, Tiwari R, Kumar M. Deciphering the complex interplay of risk factors in type 2 diabetes mellitus: A comprehensive review

The complex and multidimensional landscape of type 2 diabetes mellitus (T2D) is a major global concern. Despite several years of extensive research, the precise underlying causes of T2D remain elusive, but evidence suggests that it is influenced by a myriad of interconnected risk factors such as epigenetics, genetics, gut microbiome, environmental factors, organelle stress, and dietary habits. The number of factors influencing the pathogenesis is increasing day by day which worsens the scenario; meanwhile, the interconnections shoot up the frame. By gaining deeper insights into the contributing factors, we may pave the way for the development of personalized medicine, which could unlock more precise and impactful treatment pathways for individuals with T2D. This review summarizes the state of knowledge about T2D pathogenesis, focusing on the interplay between various risk factors and their implications for future therapeutic strategies. Understanding these factors could lead to tailored treatments targeting specific risk factors and inform prevention efforts on a population level, ultimately improving outcomes for individuals with T2D and reducing its burden globally.

Ingesting probiotic yogurt containing Lactiplantibacillus plantarum OLL2712 improves glycaemic control in adults with prediabetes in a randomized, double-blind, placebo-controlled trial

AIM

The ingestion of Lactiplantibacillus plantarum OLL2712 (OLL2712) cells has been shown to improve glucose metabolism by suppressing chronic inflammation in murine models and clinical studies. This study aimed to clarify the effect of OLL2712 on glycaemic control in healthy adults with prediabetes.

MATERIALS AND METHODS

The study was a randomized, double-blind, placebo-controlled, parallel-group design. Adult participants with prediabetes [n = 148, glycated haemoglobin (HbA1c) range: 5.6%-6.4%, age range: 20-64 years] were assigned randomly to placebo or OLL2712 groups (n = 74/group) and administered daily for 12 weeks either conventional yogurt or yogurt containing >5 × 109 heat-treated OLL2712 cells, respectively. In addition, the participants were followed for 8 weeks after the discontinuation of either yogurt. The primary outcome was the changes in HbA1c levels at weeks 12 and 16 by analysis of covariance.

RESULTS

The levels of HbA1c and glycoalbumin decreased significantly in both groups at week 12 in comparison with those at week 0, but only in the OLL2712 group at week 16. HbA1c levels decreased significantly at weeks 12 and 16 in the OLL2712 group in comparison with the placebo group (p = .014 and p = .006, respectively). No significant inter- and intragroup differences in HbA1c levels were observed at week 20.

CONCLUSIONS

The ingestion of OLL2712 prevents the deterioration of glycaemic control and maintains the HbA1c levels within the normal range in adults with prediabetes; yogurt probably exhibits similar effects, which may contribute to reducing the risk of developing type 2 diabetes.

Novel Insight into the Effect of Probiotics in the Regulation of the Most Important Pathways Involved in the Pathogenesis of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is considered one of the most common disorders worldwide. Although several treatment modalities have been developed, the existing interventions have not yielded the desired results. Therefore, researchers have focused on finding treatment choices with low toxicity and few adverse effects that could control T2DM efficiently. Various types of research on the role of gut microbiota in developing T2DM and its related complications have led to the growing interest in probiotic supplementation. Several properties make these organisms unique in terms of human health, including their low cost, high reliability, and good safety profile. Emerging evidence has demonstrated that three of the most important signaling pathways, including nuclear factor kappa B (NF-κB), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and nuclear factor erythroid 2-related factor 2 (Nrf2), which involved in the pathogenesis of T2DM, play key functions in the effects of probiotics on this disease. Hence, we will focus on the clinical applications of probiotics in the management of T2DM. Then, we will also discuss the roles of the involvement of various probiotics in the regulation of the most important signaling pathways (NF-κB, PI3K/Akt, and Nrf2) involved in the pathogenesis of T2DM.

Role of Synbiotics (Prebiotics and Probiotics) as Dietary Supplements in Type 2 Diabetes Mellitus Induced Health Complications

Diabetes is a metabolic disorder whose prevalence has become a worrying condition in recent decades. Chronic diabetes can result in serious health conditions such as impaired kidney function, stroke, blindness, and myocardial infarction. Despite a variety of currently available treatments, cases of diabetes and its complications are on the rise. This review article provides a comprehensive account of the ameliorative effect of prebiotics and probiotics individually or in combination i.e. synbiotics on health complications induced by Type 2 Diabetes Mellitus (T2DM). Recent advances in the field underscore encouraging outcomes suggesting the consumption of synbiotics leads to favorable changes in the gut microbiota. These changes result in the production of bioactive metabolites such as short-chain fatty acids (crucial for lowering blood sugar levels), reducing inflammation, preventing insulin resistance, and encouraging the release of glucagon-like peptide-1 in the host. Notably, novel strategies supplementing synbiotics to support gut microbiota are gaining attraction as pivotal interventions in mitigating T2DM-induced health complications. Thus, by nurturing a symbiotic relationship between prebiotics and probiotics i.e. synbiotics, these interventions hold promise in reshaping the microbial landscape of the gut thereby offering a multifaceted approach to managing T2DM and its associated morbidities. Supporting the potential of synbiotics underscores a paradigm shift toward holistic and targeted interventions in diabetes management, offering prospects for improved outcomes and enhanced quality of life for affected individuals. Nevertheless, more research needs to be done to better understand the single and multispecies pre/pro and synbiotics in the prevention and management of T2DM-induced health complications.

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).

Fecal Microbiota Transplantation: A Prospective Treatment for Type 2 Diabetes Mellitus

Purpose of Review

The aim of this review is to summarize the role of gastrointestinal microbiome (GM) in the development of type 2 diabetes mellitus (T2DM). Besides, we discuss the feasibility of applying FMT in the treatment of T2DM and propose a series of processes to refine the use of FMT in the treatment of T2DM.

Recent Findings

T2DM is a metabolic disease which is connected with the GM. According to many researches, GM can produce a variety of metabolites such as bile acid, short chain fatty acids, lipopolysaccharides and trimethylamine oxide which play an important role in metabolism. FMT is a method to regulate GM and has been observed to be effective in the treatment of metabolic diseases such as T2DM in some mouse models and people. However, there is still a lack of direct evidence for the use of FMT in the treatment of T2DM, and the process of FMT is not standardized.

Summary

Dysregulation of GM is closely related to the development of T2DM. Promoting the conversion of GM in T2DM patients to normal population through FMT can reduce insulin resistance and lower their blood glucose level, which is an optional treatment for T2DM patients in the future. At present, the feasibility and limitations of applying FMT to the treatment of T2DM need to be further studied.

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.

The Value of Microbiome-targeted Therapy on Lipid Indices of Patients with Type 2 Diabetes Mellitus: An Umbrella Meta-analysis of Randomized Controlled Trials

BACKGROUND

Type 2 diabetes mellitus (T2DM) is considered a global health challenge with increasing prevalence in recent years. One of the key elements in managing T2DM patients is controlling their lipid profile. Recent studies suggest microbiome-targeted therapy (MTT) as a treatment strategy for enhancing lipid profiles in these patients.

OBJECTIVE

The current study aimed to investigate the impact of MTT on lipid indices of T2DM patients by performing an umbrella approach.

METHODS

Three international databases including PubMed, Scopus, and Web of Science were searched from inception up to April 2023 to find meta-analyses evaluating the impact of MTT (prebiotics, probiotics, and synbiotics) on the lipid profile of T2DM patients. Two independent researchers extracted data from the relevant meta-analyses. To find the source of heterogeneity various subgroup analyses were performed. Comprehensive Meta-Analyses (CMA) software version 3 was utilized for the final analysis.

RESULTS

Based on the results of the current study, MTT had on significant effects total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) (ES: - 0.092; 95%CI: -0.111, -0.074; P< 0.001, ES: -0.109; 95%CI: -0.137, -0.081; P< 0.001, ES: -0.036; 95%CI: -0.068, -0.005; P= 0.024, ES: 0.109; 95%CI: 0.056, 0.162; P<0.000, respectively). In subgroup analysis, probiotics showed the most substantial effect on all lipid biomarkers.

CONCLUSION

This research has provided promising insights into the potential impact of MTT on lipid levels in patients diagnosed with T2DM. Notably, MTT had the greatest impact on HDL levels, followed by TG, TC, and LDL. As a result of our study, MTT is recommended as an adjunctive therapeutic option for T2DM treatment due to its capability to regulate lipid profiles.

The Effects of Bifidobacterium Probiotic Supplementation on Blood Glucose: A Systematic Review and Meta-Analysis of Animal Models and Clinical Evidence

Probiotic supplementation is a potential therapeutic for metabolic diseases, including obesity, metabolic syndrome (MetS), and type 2 diabetes (T2D), but most studies deliver multiple species of bacteria in addition to prebiotics or oral pharmaceuticals. This may contribute to conflicting evidence in existing meta-analyses of probiotics in these populations and warrants a systematic review of the literature to assess the contribution of a single probiotic genus to better understand the contribution of individual probiotics to modulate blood glucose. We conducted a systematic review and meta-analysis of animal studies and human randomized controlled trials (RCTs) to assess the effects of Bifidobacterium (BF) probiotic supplementation on markers of glycemia. In a meta-analysis of 6 RCTs, BF supplementation had no effect on fasting blood glucose {FBG; mean difference [MD] = -1.99 mg/dL [95% confidence interval (CI): -4.84, 0.86], P = 0.13}, and there were no subgroup differences between subjects with elevated FBG concentrations and normoglycemia. However, BF supplementation reduced FBG concentrations in a meta-analysis comprised of studies utilizing animal models of obesity, MetS, or T2D [n = 16; MD = -36.11 mg/dL (CI: -49.04, -23.18), P < 0.0001]. Translational gaps from animal to human trials include paucity of research in female animals, BF supplementation in subjects that were normoglycemic, and lack of methodologic reporting regarding probiotic viability and stability. More research is necessary to assess the effects of BF supplementation in human subjects with elevated FBG concentrations. Overall, there was consistent evidence of the efficacy of BF probiotics to reduce elevated FBG concentrations in animal models but not clinical trials, suggesting that BF alone may have minimal effects on glycemic control, may be more effective when combined with multiple probiotic species, or may be more effective in conditions of hyperglycemia rather than elevated FBG concentrations.

Gut microbial metabolic signatures in diabetes mellitus and potential preventive and therapeutic applications

Diabetes mellitus can be subdivided into several categories based on origin and clinical characteristics. The most common forms of diabetes are type 1 (T1D), type 2 diabetes (T2D) and gestational diabetes mellitus (GDM). T1D and T2D are chronic diseases affecting around 537 million adults worldwide and it is projected that these numbers will increase by 12% over the next two decades, while GDM affects up to 30% of women during pregnancy, depending on diagnosis methods. These forms of diabetes have varied origins: T1D is an autoimmune disease, while T2D is commonly associated with, but not limited to, certain lifestyle patterns and GDM can result of a combination of genetic predisposition and pregnancy factors. Despite some pathogenic differences among these forms of diabetes, there are some common markers associated with their development. For instance, gut barrier impairment and inflammation associated with an unbalanced gut microbiota and their metabolites may be common factors in diabetes development and progression. Here, we summarize the microbial signatures that have been linked to diabetes, how they are connected to diet and, ultimately, the impact on metabolite profiles resulting from host-gut microbiota-diet interactions. Additionally, we summarize recent advances relating to promising preventive and therapeutic interventions focusing on the targeted modulation of the gut microbiota to alleviate T1D, T2D and GDM.

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.

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.

Probiotics and Their Role in the Management of Type 2 Diabetes Mellitus (Short-Term Versus Long-Term Effect): A Systematic Review and Meta-Analysis

Diabetes is a major economic burden and an illness with a rising incidence worldwide. Type 2 diabetes mellitus (T2DM), the most prevalent kind of diabetes, is characterized by insulin resistance and insufficient insulin production. Recent research has implicated gut microbiota dysbiosis as a contributing factor to T2DM pathogenesis. The present study employed a methodology based on randomized controlled trials (RCTs) to assess the therapeutic efficacy of probiotics in the treatment of T2DM. A thorough search was done in PubMed and Medline for articles written in English and published between 2017 and 2023. Studies were chosen based on predetermined inclusion criteria, and the search technique adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principles. This study also employed a robust assessment instrument, widely recognized in the medical and health sciences, to evaluate the potential presence of bias within the selected research studies. Out of 96 identified articles, 22 RCTs met the eligibility criteria. Both short-term (8 weeks or less) and long-term (12 weeks or more) probiotic administrations were made. The results of the meta-analysis demonstrated a significant improvement in the homeostatic model assessment of insulin resistance (HOMA-IR) following the probiotic intervention (P=0.02) and considerably decreased glycated hemoglobin HbA1c levels (P=0.004) and fasting blood glucose (FBG) levels (P<0.0001) in T2DM patients compared to placebo. This research offers proof that probiotics are clinically effective in the treatment of T2DM. Probiotic supplementation demonstrated favorable effects on glycemic control markers. However, the findings from RCTs were heterogeneous, and some studies showed inconsistent results. To clarify the processes underlying the probiotics' therapeutic benefits and to determine the best probiotic strains, doses, and therapy durations, more research is required. Nevertheless, probiotics offer a promising therapeutic approach for T2DM management and warrant consideration as a potential adjunct therapy in clinical practice.

Evidence for the Beneficial Effects of Brazilian Native Fruits and Their By-Products on Human Intestinal Microbiota and Repercussions on Non-Communicable Chronic Diseases-A Review

Non-communicable chronic diseases (NCDs) are the most widespread cause of mortality worldwide. Intestinal microbiota balance can be altered by changes in the abundance and/or diversity of intestinal microbiota, indicating a role of intestinal microbiota in NCD development. This review discusses the findings of in vitro studies, pre-clinical studies and clinical trials on the effects of Brazilian native fruits, their by-products, as well as their bioactive compounds on human intestinal microbiota and NCD. The major bioactive compounds in Brazilian native fruits and their by-products, and the impacts of their administration on outcomes linked to intestinal microbiota modulation are discussed. Mechanisms of intestinal microbiota affecting NCD could be linked to the modulation of absorption and energy balance, immune and endocrine systems, and inflammatory response. Brazilian native fruits, such as acerola, açaí, baru, buriti, guava, jabuticaba, juçara, and passion fruit, have several bioactive compounds, soluble and insoluble fibers, and a variety of phenolic compounds, which are capable of changing these key mechanisms. Brazilian native fruits and their by-products can help to promote positive intestinal and systemic health benefits by driving alterations in the composition of the human intestinal microbiota, and increasing the production of distinct short-chain fatty acids and phenolic metabolites, thereby enhancing intestinal integrity and homeostasis. Evidence from available literature shows that the modulatory impacts of Brazilian native fruits and their by-products on the composition and metabolic activity of the intestinal microbiota could improve several clinical repercussions associated with NCD, reinforcing the influence of intestinal microbiota in extra-intestinal outcomes.

Effects of Bifidobacterium BL21 and Lacticaseibacillus LRa05 on gut microbiota in type 2 diabetes mellitus mice

Gut dysbiosis causes damage to the intestinal barrier and is associated with type 2 diabetes mellitus (T2DM). We tested the potential protective effects of probiotic BL21 and LRa05 on gut microbiota in type 2 diabetes mellitus mice and determined whether these effects were related to the modulation of gut microbiota.Thirty specific pathogen-free C57BL/6J mice were randomly allocated to three groups-the (CTL) control group, HFD/STZ model (T2DM) group, and HFD/STZ-probiotic intervention (PRO) group-and intragastrically administered strains BL21 and LRa05 for 11 weeks. The administration of strains BL21 and LRa05 significantly regulated blood glucose levels, accompanied by ameliorated oxidative stress in mice. The BL21/LRa05-treated mice were protected from liver, cecal, and colon damage. Microbiota analysis showed that the cecal and fecal microbiota of the mice presented significantly different spatial distributions from one another. Principal coordinate analysis results indicated that both T2DM and the BL21/LRa05 intervention had significant effects on the cecal contents and fecal microbiota structure. In terms of the fecal microbiota, an abundance of Akkermansia and Anaeroplasma was noted in the PRO group. In terms of the cecal content microbiota, enrichment of Akkermansia, Desulfovibrio, Bifidobacterium, Lactobacillus, and Limosilactobacillus was noted in the PRO group. The probiotics BL21 and LRa05 prevent or ameliorate T2DM by regulating the intestinal flora and reducing inflammation and oxidative stress. Our results suggest that BL21 and LRa05 colonize in the cecum. Thus, BL21/LRa05 combined with probiotics having a strong ability to colonize in the colon may achieve better therapeutic effects in T2DM. Our study illustrated the feasibility and benefits of the combined use of probiotics and implied the importance of intervening at multiple intestinal sites in T2DM mice.

Effects of combined treatment of probiotics and metformin in management of Type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

Lifestyle changes and dietary intervention, including the use of probiotics, can modulate dysbiosis of gut microbiome and contribute to the management of type 2 diabetes mellitus (T2DM). This systematic review and meta-analysis aim to assess the efficacy of metformin plus probiotics versus metformin alone on outcomes in patients with T2DM.

METHODS

We searched MEDLINE and EMBASE from inception to February 2023 to identify all randomized controlled trials (RCTs), which compared the use of metformin plus probiotics versus metformin alone in adult patients with T2DM. Data were summarized as mean differences (MD) with 95% confidence interval (CI) and pooled under the random effects model. Findings Fourteen RCTs (17 comparisons, 1009 patients) were included in this systematic review. Pooled results show a significant decrease in fasting glucose (FG) (MD=-0.64, 95% CI=-1.06, -0.22) and HbA1c (MD=-0.29, 95% CI=-0.47, -0.10) levels in patients with T2DM treated with metformin plus probiotics versus metformin alone. The addition of probiotics to metformin resulted in lower odds of gastrointestinal adverse events (Odds ratio=0.18, 95% CI=0.09, 0.3.8; I²=0%).

CONCLUSIONS

The addition of probiotics to metformin therapy is associated with improvement in T2DM outcomes. However, high-quality and adequately reported RCTs are needed in the future to confirm our findings.

Maternal microbiota and gestational diabetes: impact on infant health

Gestational diabetes mellitus (GDM) is a common complication of pregnancy that has been associated with an increased risk of obesity and diabetes in the offspring. Pregnancy is accompanied by tightly regulated changes in the endocrine, metabolic, immune, and microbial systems, and deviations from these changes can alter the mother's metabolism resulting in adverse pregnancy outcomes and a negative impact on the health of her infant. Maternal microbiomes are significant drivers of mother and child health outcomes, and many microbial metabolites are likely to influence the host health. This review discusses the current understanding of how the microbiota and microbial metabolites may contribute to the development of GDM and how GDM-associated changes in the maternal microbiome can affect infant's health. We also describe microbiota-based interventions that aim to improve metabolic health and outline future directions for precision medicine research in this emerging field.

Evaluation of Rouxiella badensis Subsp Acadiensis (Canan SV-53) as a Potential Probiotic Bacterium

The advent of omic platforms revealed the significant benefits of probiotics in the prevention of many infectious diseases. This led to a growing interest in novel strains of probiotics endowed with health characteristics related to microbiome and immune modulation. Therefore, autochthonous bacteria in plant ecosystems might offer a good source for novel next-generation probiotics. The main objective of this study was to analyze the effect of Rouxiella badensis acadiensis Canan (R. acadiensis) a bacterium isolated from the blueberry biota, on the mammalian intestinal ecosystem and its potential as a probiotic microorganism. R. acadiensis, reinforced the intestinal epithelial barrier avoiding bacterial translocation from the gut to deep tissues, even after feeding BALB/c mice for a prolonged period of time. Moreover, diet supplementation with R. acadiensis led to increases in the number of Paneth cells, well as an increase in the antimicrobial peptide α defensin. The anti-bacterial effect of R. acadiensis against Staphylococcus aureus and Salmonella enterica serovar Typhimurium was also reported. Importantly, R. acadiensis-fed animals showed better survival in an in vivo Salmonella enterica serovar Typhimurium challenge compared with those that received a conventional diet. These results demonstrated that R. acadiensis possesses characteristics of a probiotic strain by contributing to the reinforcement and maintenance of intestinal homeostasis.

Fecal microbiota transplantation ameliorates type 2 diabetes via metabolic remodeling of the gut microbiota in db/db mice

INTRODUCTION

Gut microbiome (GM) deregulation has been implicated in major conditions such as obesity and type 2 diabetes (T2DM). Our previous prospective study indicated that fecal microbiota transplantation (FMT) successfully improved patients with T2DM. We hypothesized that FMT may be a potential therapeutic method for T2DM, but its precise mechanisms in T2DM remains to be elucidated.

RESEARCH DESIGN AND METHODS

Eight db/m mice were FMT donors and control mice, and 16 genetically diabetic db/db mice were equally divided into two groups (db/db+phosphate-buffered saline (PBS) group, db/db+FMT group). The db/db+FMT group was administered fresh fecal suspension (0.2 mL/mice) daily for 4 weeks. Analysis of the GM and serum metabolome was carried out by 16S ribosomal RNA sequencing and liquid chromatogram-mass spectrometry, respectively. Effects of FMT on the gut barrier and pancreas were assessed using protein assays, messenger RNA, immunohistology and clinical indicators testing.

RESULTS

Our results showed that FMT treatment of db/db mice relieves a series of clinical indicators, including fasting plasma glucose, serum insulin and oral glucose tolerance test among others. Compared with non-diabetic control mice, db/db+PBS mice exhibited decreased abundance of Ruminococaceae, Porphyromonadaceae and increased abundance of Rikenellaceae and Lactobacillaceae. FMT treatment reversed this effect on the microbiome. Eleven metabolites were changed between the db/db+PBS and db/db+FMT groups. Correlation analysis showed that the structural changes of the GM were correlated with host metabolite levels. We further showed that FMT treatment of db/db mice improved intestinal barrier function, reduced inflammation and caused an alteration in the number of circulating immune cells.

CONCLUSIONS

FMT-mediated changes in the GM, serum metabolites, intestinal epithelial barrier, inflammation and circulating immune cells play an important role in the efficacy of FMT on T2DM disease progression.

The Beneficial Effects of a Multispecies Probiotic Supplement on Glycaemic Control and Metabolic Profile in Adults with Type 1 Diabetes: A Randomised, Double-Blinded, Placebo-Controlled Pilot-Study

Objective

In this pilot-study, the effects of a multispecies probiotic supplement on glycaemic control and metabolic parameters in adults with type 1 diabetes (T1DM) were explored.

Material and Methods

A total of 50 T1DM patients were enrolled and randomly placed into a group receiving capsules containing multi-probiotic strains (Bifidobacterium longum, Lactobacterium bulagricumi, Streptococcus thermophilus) and insulin (probiotics group, n = 27) or a group receiving a placebo and insulin (placebo group, n = 23). All patients underwent continuous glucose monitoring at baseline and 12 weeks after intervention. The primary outcomes were determined by comparing factors such as changes in fasting blood glucose (FBG) and haemoglobin A1c (HbA1c) between the groups.

Results

Probiotic supplementation significantly reduced FBG (-1.0 ± 4.7 vs 1.8 ± 4.7 mmol/L, p = 0.048), 30 min postprandial glucose (-0.5 ± 4.6 vs 1.9 ± 3.3 mmol/L, p = 0.0495), and low-density lipoprotein cholesterol (-0.07 ± 0.45 vs 0.32 ± 0.78 mmol/L, p = 0.0413), compared with the placebo. Although not statistically significant, probiotic supplementation also lowered HbA1c levels by 0.49% (-5.33 mmol/mol, p = 0.310). Besides, no significant difference was observed in the continuous glucose monitoring (CGM) parameters between the two groups. Further subgroup analysis revealed a significant reduction in mean sensor glucose (MSG; -0.75 (-2.11, 0.48) mmol/L vs 1.51 (-0.37, 2.74) mmol/L, p = 0.010) and time above range (TAR; -5.47 (-20.1, 3.04)% vs 18.9 (-1.11, 35.6)%, p = 0.006), as well as an greater improvement in the time in range (TIR; 9.32 (-4.84, 16.6)% vs -19.9 (-31.4, 0.69)%, p = 0.005) in male patients than female patients in the probiotics group.

Conclusion

Multispecies probiotics exerted beneficial effects on fasting and postprandial glucose and lipid profiles in adult T1DM patients, especially for male patients and those with higher baseline FBG levels.

Effects of Probiotic and Selenium Co-supplementation on Lipid Profile and Glycemia Indices: A Systematic Review and Meta-analysis of Randomized Clinical Trials

PURPOSE OF REVIEW

The current systematic review and meta-analysis was done to evaluate the effects of selenium and probiotic co-supplementation on lipid profile and glycemia indices of the adult population using randomized controlled clinical trials (RCTs).

RECENT FINDINGS

Five studies involving 282 participants with a sample size ranging from 38 to 79 were eligible to be enrolled in the current study. Co-supplementation with probiotic and selenium reduced fasting plasma glucose (WMD =  -4.02 mg/dL; 95% CI: -5.87 to -2.18; P < 0.001), insulin (WMD =  -2.50 mIU/mL; 95% CI: -3.11 to -1.90; P < 0.001), homeostatic model assessment for insulin resistance (WMD =  -0.59; 95% CI: -0.74 to -0.43; P < 0.001), quantitative insulin sensitivity check index (WMD = 0.01; 95% CI: 0.01 to 0.02; P < 0.001), total cholesterol (WMD =  -12.75 mg/dL; 95% CI: -19.44 to -6.07; P < 0.001), low-density lipoprotein cholesterol (WMD =  -7.09 mg/dL; 95% CI: -13.45 to -0.73; P = 0.029), and triglyceride (WMD =  -14.38 mg/dL; 95% CI: -23.13 to -5.62; P = 0.001). The findings of the current systematic review and meta-analysis suggested that co-supplementation with probiotics and selenium may benefit adults in terms of glycemia indices and lipid profile. However, due to the small number of included studies, further trials are needed to confirm our findings.

Probiotics and Prebiotics as Dietary Supplements for the Adjunctive Treatment of Type 2 Diabetes

In modern lifestyles, high-fat diets and prolonged inactivity lead to more people developing type 2 diabetes (T2D). Based on the modern pathogenesis of T2D, food, and its components have become one of the top concerns for patients. Recent studies have found that dysbiosis and gut-related inflammation are more common in T2D patients. Probiotics and prebiotics play complementary roles in the gut as dietary supplements. Together, they may help improve dysbiosis and intestinal inflammation in people with T2D, increase the production of blood glucose-lowering hormones such as incretin, and help reduce insulin resistance and lower blood glucose. Therefore, changing the dietary structure and increasing the intake of probiotics and prebiotics is expected to become a new strategy for the adjuvant treatment of T2D.

Preventive effect of Ya'an Tibetan tea on obesity in rats fed with a hypercaloric high-fat diet revealed by gut microbiology and metabolomics studies

Ya'an Tibetan Tea (YATT) is a classic dark tea variety fermented with a unique geographical environment and traditional craftsmanship. Previous research indicates that it is beneficial for obesity and related metabolic disorders, but no systematic research currently reveals its precise mechanisms. This work investigated the preventive effect of YATT on obesity and the corresponding potential mechanisms by performing 16S rRNA gene sequencing and metabolomics studies. Our results demonstrated that YATT could significantly improve the body weight and fat deposition in hypercaloric high-fat diet (HFD)-induced obese rats, enhance antioxidant enzymes activity and reduce inflammation, and reverse the liver damage caused by an HFD. Moreover, 16S rRNA analysis showed that YATT could improve the intestinal microbial disorders caused by the HFD by significantly reversing the increase in Firmicutes/Bacteroidetes（F/B）ratio and the relative abundance of flora associated with the HFD, such as unclassified_Lachnospiraceae and Romboutsia flora. In addition, metabolomic analysis of cecum contents identified 121 differential metabolites, of which 19 were common to all experimental rats fed with and without a high-fat diet. Strikingly, 17 of the most prevalent 19 differential metabolites, including Theobromine, L-Valine, and Diisobutyl phthalate, were considerably reversed by YATT. Enrichment analysis of the metabolic pathways of these differential metabolites indicated that Caffeine metabolism, Phenylalanine metabolism, and Lysine degradation are the potential metabolic pathways responsible for the obesity prevention effect of YATT. Collectively, this work revealed that YATT has good potential for obesity prevention and the improvement of intestinal microbial communities, potentially due to the YATT-induced alterations in the metabolic pathways and functional metabolite levels of caffeine and amino acids. These results inform the material basis of YATT for obesity prevention and its mechanisms and provide essential insights for developing YATT as a healthy beverage for obesity prevention.

Combinations of Tibetan tea and medicine food homology herbs: A new strategy for obesity prevention

Obesity has become a significant global public health problem. Functional drinks have been an essential direction for obesity prevention research. The present study investigated the preventive effect and safety of winter melon and lotus leaf Tibetan tea (WLTT, a compound tea drink based on Ya'an Tibetan Tea and medicine food homology herbs) on obesity. The rats' hypercaloric high-fat diet (HFD) obesity model was established to evaluate obesity prevention and explored the mechanism through intestinal flora regulation. The results showed that in obese rats with the intervention of WLTT (400, 800, and 1600 mg/kg BW), the body weight, fat accumulation, adipocyte cell size, serum lipid levels, and antioxidant enzyme activity (SOD, GSH-Px, and MDA) were progressively improved. 16S rRNA high-throughput sequencing showed that WLTT could improve intestinal flora disorders due to HFD, which significantly reversed the relative abundance of Firmicutes and the F/B ratio associated with an HFD, and significantly upregulated the relative abundance of Verrucomicrobia. At the genus level, the downregulation of the relative abundance of Akkermansia and unclassified_Lachnospiraceae groups, and the upregulation of the relative abundance of Romboutsia, Ruminococcus, Corynebacteriume, and Saccharibacteria_genera_incertae_sedis groups brought about by the HFD were significantly reversed. The results of the above experiments were compared favorably with those of a parallel experiment with Bi -Sheng -Yuan slimming tea (BSY, a functional drink based on green tea and medicine food homology herbs). Overall, the findings have provided that WLTT can prevent obesity owing to an HFD by regulating intestinal flora and has a good safety profile, and combinations of Tibetan tea and medicine food homology herbs could be a new option for obesity prevention.

Type 2 Diabetes and the Microbiome

Diabetes represents one of the most significant, and rapidly escalating, global healthcare crises we face today. Diabetes already affects one-tenth of the world's adults-more than 537 million people, numbers that have tripled since 2000 and are estimated to reach 643 million by 2030. Type 2 diabetes (T2D), the most prevalent form, is a complex disease with numerous contributing factors, including genetics, epigenetics, diet, lifestyle, medication use, and socioeconomic factors. In addition, the gut microbiome has emerged as a significant potential contributing factor in T2D development and progression. Gut microbes and their metabolites strongly influence host metabolism and immune function, and are now known to contribute to vitamin biosynthesis, gut hormone production, satiety, maintenance of gut barrier integrity, and protection against pathogens, as well as digestion and nutrient absorption. In turn, gut microbes are influenced by diet and lifestyle factors such as alcohol and medication use, including antibiotic use and the consumption of probiotics and prebiotics. Here we review current evidence regarding changes in microbial populations in T2D and the mechanisms by which gut microbes influence glucose metabolism and insulin resistance, including inflammation, gut permeability, and bile acid production. We also explore the interrelationships between gut microbes and different T2D medications and other interventions, including prebiotics, probiotics, and bariatric surgery. Lastly, we explore the particular role of the small bowel in digestion and metabolism and the importance of studying small bowel microbes directly in our search to find metabolically relevant biomarkers and therapeutic targets for T2D.

The Metabolic Role and Therapeutic Potential of the Microbiome

We are host to an assembly of microorganisms that vary in structure and function along the length of the gut and from the lumen to the mucosa. This ecosystem is collectively known as the gut microbiota and significant efforts have been spent during the past 2 decades to catalog and functionally describe the normal gut microbiota and how it varies during a wide spectrum of disease states. The gut microbiota is altered in several cardiometabolic diseases and recent work has established microbial signatures that may advance disease. However, most research has focused on identifying associations between the gut microbiota and human diseases states and to investigate causality and potential mechanisms using cells and animals. Since the gut microbiota functions on the intersection between diet and host metabolism, and can contribute to inflammation, several microbially produced metabolites and molecules may modulate cardiometabolic diseases. Here we discuss how the gut bacterial composition is altered in, and can contribute to, cardiometabolic disease, as well as how the gut bacteria can be targeted to treat and prevent metabolic diseases.

Potential role of Limosilactobacillus fermentum as a probiotic with anti-diabetic properties: A review

Oxidative stress, inflammation, and gut microbiota impairments have been implicated in the development and maintenance of diabetes mellitus. Strategies capable of recovering the community of commensal gut microbiota and controlling diabetes mellitus have increased in recent years. Some lactobacilli strains have an antioxidant and anti-inflammatory system capable of protecting against oxidative stress, inflammation, and diabetes mellitus. Experimental studies and some clinical trials have demonstrated that Limosilactobacillus fermentum strains can beneficially modulate the host antioxidant and anti-inflammatory system, resulting in the amelioration of glucose homeostasis in diabetic conditions. This review presents and discusses the currently available studies on the identification of Limosilactobacillus fermentum strains with anti-diabetic properties, their sources, range of dosage, and the intervention time in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of Limosilactobacillus fermentum strains capable of inducing anti-diabetic effects and promoting health benefits.

Role of probiotics/synbiotic supplementation in glycemic control: A critical umbrella review of meta-analyses of randomized controlled trials

The evidence regarding the beneficial effects of probiotics/synbiotic supplementation have been revealed by several meta-analyses, however some of these studies have fielded inconsistent results and a conclusion has yet to be reached. Therefore, the aim of present umbrella meta-analyses was to assess relevant evidence and elucidate the efficacy of probiotics/synbiotic supplementation in glycemic control. A comprehensive search in four databases (Cochrane library, PubMed, Web of science and Scopus) was performed to collect relevant studies up to August 2022, the pooled effects were measured with the use of random/fix-effect model depends on the heterogeneity. A total of 47 eligible meta-analyses involving 47,720 participants were identified to evaluate the pooled effects. The overall results showed that probiotics/synbiotic supplementation delivered significant decreases in fast plasma glucose (ES = -0.408, 95% CI: -0.518, -0.298; P < 0.001; I2 = 82.996, P < 0.001), fast plasma insulin (ES = -1.165, 95% CI: -1.454, -0.876; P < 0.001; I2 = 89.629, P < 0.001), homeostasis model assessment of insulin resistance (ES = -0.539, 95% CI: -0.624, -0.454; P < 0.001; I2 = 56.716, P < 0.001), and glycosylated hemoglobin (ES = -0.186, 95% CI: -0.270, -0.102; P < 0.001; I2 = 59.647, P = 0.001). Subgroup analysis showed that patients with impaired glucose homeostasis might benefit the most from probiotics/synbiotic supplementation. In conclusion, current umbrella meta-analysis strongly supporting the beneficial health effects of probiotics/synbiotic supplementation in glycemic control.

Sponsorship Bias in Clinical Trials in the Dental Application of Probiotics: A Meta-Epidemiological Study

Many experimental and clinical trials have investigated the dental application of probiotics, although the evidence concerning the effects of probiotic supplements is conflicting. We aimed to examine whether sponsorship in trials about dental applications of probiotics is associated with biased estimates of treatment effects. Overall, 13 meta-analyses involving 48 randomized controlled trials (23 with high risk of sponsorship bias, 25 with low risk) with continuous outcomes were included. Effect sizes were calculated from differences in means of first reported continuous outcomes, divided by the pooled standard deviation. For each meta-analysis, the difference in standardized mean differences between high-risk and low-risk trials was estimated by random effects meta-regression. Differences in standardized mean differences (DSMDs) were then calculated via meta-analyses in a random effects meta-analysis model. A combined DSMD of greater than zero indicated that high-risk trials showed more significant treatment effects than low-risk trials. The results show that trials with a high risk of sponsorship bias showed more significant intervention effects than did low-risk trials (combined DSMD, 0.06; 95% confidence interval, 0.3 to 0.9; p < 0.001), with low heterogeneity among meta-analyses (I2 = 0%; between-meta-analyses variance τ2 = 0.00). Based on our study, high-risk clinical trials with continuous outcomes reported more favorable intervention effects than did low-risk trials in general.

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.

Efficacy and Safety of Nutrient Supplements for Glycaemic Control and Insulin Resistance in Type 2 Diabetes: An Umbrella Review and Hierarchical Evidence Synthesis

Background: Nutrient supplements are widely used for type 2 diabetes (T2D), yet evidence-based guidance for clinicians is lacking. Methods: We searched the four electronic databases from November 2015−December 2021. The most recent, most comprehensive, high-ranked systematic reviews, meta-analyses, and/or umbrella reviews of randomised controlled trials in adults with T2D were included. Data were extracted on study characteristics, aggregate outcome measures per group (glycaemic control, measures of insulin sensitivity and secretion), adverse events, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessments. Quality was assessed using A Measurement Tool to Assess Systematic Reviews Version 2.0 (AMSTAR 2). Results: Twelve meta-analyses and one umbrella review were included. There was very low certainty evidence that chromium, Vitamin C, and omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) were superior to placebo for the primary outcome of glycated hemoglobin (HbA1c) (Mean Difference/MD −0.54, −0.54 and ES −0.27, respectively). Probiotics were superior to placebo for HbA1c (Weighted Mean Difference/WMD −0.43%). There was very low certainty evidence that Vitamin D was superior to placebo for lowering HbA1c in trials of <6 months (MD −0.17%). Magnesium, zinc, Vitamin C, probiotics, and polyphenols were superior to placebo for FBG. Vitamin D was superior to placebo for insulin resistance. Data on safety was limited. Conclusions: Future research should identify who may benefit from nutrient supplementation, safety, and optimal regimens and formulations.

Gut microbiota-derived metabolites as key actors in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is one of the most risk factors threatening human health. Although genetic and environmental factors contribute to the development of T2DM, gut microbiota has also been found to be involved. Gut microbiota-derived metabolites are a key factor in host-microbe crosstalk, and have been revealed to play a central role in the physiology and physiopathology of T2DM. In this review, we provide a timely and comprehensive summary of the microbial metabolites that are protective or causative for T2DM, including some amino acids-derived metabolites, short-chain fatty acids, trimethylamine N-oxide, and bile acids. The mechanisms by which metabolites affect T2DM have been elaborated. Knowing more about these processes will increase our understanding of the causal relationship between gut microbiota and T2DM. Moreover, some frontier therapies that target gut microbes and their metabolites to improve T2DM, including dietary intervention, fecal microbiota transplantation, probiotics, prebiotics or synbiotics intervention, and drugging microbial metabolism, have been critically discussed. This review may provide novel insights for the development of targeted and personalized treatments for T2DM based on gut microbial metabolites. More high-quality clinical trials are needed to accelerate the clinical translation of gut-targeted therapies for T2DM.

Antidiabetic Effects of Pediococcus acidilactici pA1c on HFD-Induced Mice

Prediabetes (PreD), which is associated with impaired glucose tolerance and fasting blood glucose, is a potential risk factor for type 2 diabetes mellitus (T2D). Growing evidence suggests the role of the gastrointestinal microbiota in both PreD and T2D, which opens the possibility for a novel nutritional approach, based on probiotics, for improving glucose regulation and delaying disease progression of PreD to T2D. In this light, the present study aimed to assess the antidiabetic properties of Pediococcus acidilactici (pA1c) in a murine model of high-fat diet (HFD)-induced T2D. For that purpose, C57BL/6 mice were given HFD enriched with either probiotic (1 × 10¹⁰ CFU/day) or placebo for 12 weeks. We determined body weight, fasting blood glucose, glucose tolerance, HOMA-IR and HOMA-β index, C-peptide, GLP-1, leptin, and lipid profile. We also measured hepatic gene expression (G6P, PEPCK, GCK, IL-1β, and IL-6) and examined pancreatic and intestinal histology (% of GLP-1⁺ cells, % of goblet cells and villus length). We found that pA1c supplementation significantly attenuated body weight gain, mitigated glucose dysregulation by reducing fasting blood glucose levels, glucose tolerance test, leptin levels, and insulin resistance, increased C-peptide and GLP-1 levels, enhanced pancreatic function, and improved intestinal histology. These findings indicate that pA1c improved HFD-induced T2D derived insulin resistance and intestinal histology, as well as protected from body weight increase. Together, our study proposes that pA1c may be a promising new dietary management strategy to improve metabolic disorders in PreD and T2D.

The effects of dietary supplements and natural products targeting glucose levels: an overview

Identifying effective dietary supplements and medicinal herbs has attracted the attention of clinicians and researchers to complement the standard treatment in controlling diabetes mellitus. In the present overview, we aimed to collect studies with the highest level of evidence to shed light on detecting the most effective dietary supplements and medicinal herbs for controlling glycemic status. For the current overview, four electronic databases, including PubMed, Scopus, Web of Science, and Cochrane Library, were systematically searched from inception to 31 December 2020 and then updated until 1 October 2021 to obtain eligible meta-analyses on either dietary supplements or medicinal herbs and their effects on glycemic status. Fasting blood sugar (FBS) and Hemoglobin A1C (HbA1C) were considered as primary outcomes. Finally, ninety-one meta-analyses on dietary supplements (n = 55) and herbs (n = 36) were included. Evidence showed positive effects of chromium, zinc, propolis, aloe vera, milk thistle, fenugreek, cinnamon, ginger, and nettle on FBS and/or HbA1C. However, mostly the heterogeneity (I2) was high. Other supplements and herbs also showed no reduction in glucose levels or their effects were small. Although some dietary supplements and medicinal herbs showed a significant reduction in FBS and/or HbA1C, mostly their effects from the clinical point of view were not remarkable. In addition, due to high heterogeneity, publication bias, and a limited number of included studies in most cases further clinical trials are needed for making decision on anti-diabetic supplement efficacy.

Increased circulating butyrate and ursodeoxycholate during probiotic intervention in humans with type 2 diabetes

Background

An increasing body of evidence implicates the resident gut microbiota as playing a critical role in type 2 diabetes (T2D) pathogenesis. We previously reported significant improvement in postprandial glucose control in human participants with T2D following 12-week administration of a 5-strain novel probiotic formulation (‘WBF-011’) in a double-blind, randomized, placebo controlled setting (NCT03893422). While the clinical endpoints were encouraging, additional exploratory measurements were needed in order to link the motivating mechanistic hypothesis - increased short-chain fatty acids - with markers of disease.

Results

Here we report targeted and untargeted metabolomic measurements on fasting plasma (n = 104) collected at baseline and end of intervention. Butyrate and ursodeoxycholate increased among participants randomized to WBF-011, along with compelling trends between butyrate and glycated haemoglobin (HbA1c). In vitro monoculture experiments demonstrated that the formulation’s C. butyricum strain efficiently synthesizes ursodeoxycholate from the primary bile acid chenodeoxycholate during butyrogenic growth. Untargeted metabolomics also revealed coordinated decreases in intermediates of fatty acid oxidation and bilirubin, potential secondary signatures for metabolic improvement. Finally, improvement in HbA1c was limited almost entirely to participants not using sulfonylurea drugs. We show that these drugs can inhibit growth of formulation strains in vitro.

Conclusion

To our knowledge, this is the first description of an increase in circulating butyrate or ursodeoxycholate following a probiotic intervention in humans with T2D, adding support for the possibility of a targeted microbiome-based approach to assist in the management of T2D. The efficient synthesis of UDCA by C. butyricum is also likely of interest to investigators of its use as a probiotic in other disease settings. The potential for inhibitory interaction between sulfonylurea drugs and gut microbiota should be considered carefully in the design of future studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02415-8.

Gut microbiota: A new target for T2DM prevention and treatment

Type 2 diabetes mellitus (T2DM), one of the fastest growing metabolic diseases, has been characterized by metabolic disorders including hyperglycemia, hyperlipidemia and insulin resistance (IR). In recent years, T2DM has become the fastest growing metabolic disease in the world. Studies have indicated that patients with T2DM are often associated with intestinal flora disorders and dysfunction involving multiple organs. Metabolites of the intestinal flora, such as bile acids (BAs), short-chain fatty acids (SCFAs) and amino acids (AAs)may influence to some extent the decreased insulin sensitivity associated with T2DM dysfunction and regulate metabolic as well as immune homeostasis. In this paper, we review the changes in the gut flora in T2DM and the mechanisms by which the gut microbiota modulates metabolites affecting T2DM, which may provide a basis for the early identification of T2DM-susceptible individuals and guide targeted interventions. Finally, we also highlight gut microecological therapeutic strategies focused on shaping the gut flora to inform the improvement of T2DM progression.

Prevention and treatment strategies for type 2 diabetes based on regulating intestinal flora

Diabetes along with related comorbidities associated with high disability rates severely threatens human health. The etiology of diabetes is complex. Genetics, environmental factors, eating habits, drug usage, aging, and lack of movement play important roles in the development of diabetes. Intestinal flora is reportedly closely related to the occurrence and development of type 2 diabetes. Herein, we review changes in abundance and proportion of intestinal flora in patients with type 2 diabetes and regulation of intestinal flora through diet, drugs, and surgery to prevent and treat type 2 diabetes. A more appropriate clinical diagnosis and treatment plan could be made considering changes in intestinal flora in the future.

Preventive Effect and Molecular Mechanism of Lactobacillus rhamnosus JL1 on Food-Borne Obesity in Mice

Probiotics can prevent obesity and related metabolic complications. In our study, the protective effect and molecular mechanism of Lactobacillus rhamnosus JL1 (separated from the feces of healthy infants) on high-fat diet mice were investigated. After 10 weeks of dietary intervention with L. rhamnosus JL1 intervention, the body weight of the JL1 group (23.78 g) was significantly lower than that of the HFD group (26.59 g, p < 0.05) and the liver index was reduced. Serum biochemical analysis showed that the TC, TG and LDL-C contents of JL1 group mice were significantly decreased (p < 0.05). Histological images of the mice livers showed that the degree of lipid action and damage of hepatic cells were improved. L. rhamnosus JL1 activated the AMPK pathway, and reduced the gene expression of PPAR-γ, LXR-α and SREBP-1C. In addition, the protein expression of PPAR-γ and LXR-α were reduced. After dietary intervention with L. rhamnosus JL1, the concentration of acetic acid, propionic acid, and butyric acid were increased significantly, especially the concentration of butyric acid, which was 63.16% higher than that of the HFD group (p < 0.05). In conclusion, this study provided a theoretical reference for the development and application of probiotics derived from healthy infant feces in health products and functional foods.