The effects of probiotic administration on patients with prediabetes: a meta-analysis and systematic review

Effects of synbiotic supplementation on the components of metabolic syndrome in patients with schizophrenia: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Antipsychotic drugs may have adverse effects on the components of metabolic syndrome. Previous studies have shown that changes in the intestinal microbiome are associated with metabolic disturbances in patients with schizophrenia. The objective of this study was to determine the effects of synbiotics on the components of metabolic syndrome as primary outcomes in patients with schizophrenia. Secondary outcomes were HbA1c, insulin resistance, LDL-c, and anthropometric measurements.

METHODS

In this double-blind, placebo-controlled trial, seventy patients with schizophrenia receiving antipsychotic drugs who had at least two criteria of metabolic syndrome were randomly divided into two groups to receive either two capsules of a synbiotic supplement or a placebo daily for 8 weeks. Anthropometric indices and biochemical parameters were measured at baseline and after the intervention.

RESULTS

Fifty-five patients completed the study. The synbiotic supplement significantly decreased waist circumference and HbA1C compared to placebo (-2.66 ± 4.20 vs. 3.03 ± 4.50 and - 0.26 ± 0.54 vs. 0.20 ± 0.75, respectively). Although BMI did not change significantly in the synbiotic + antipsychotic group, it increased in the placebo + antipsychotic group (-0.37 ± 1.00 vs. 0.61 ± 1.09 P < 0.5). LDL-c and triglyceride (TG) levels decreased significantly in the synbiotic + antipsychotic group, but the change was not significantly different from that of the placebo + antipsychotic group. FBS, HDL-c, systolic and diastolic blood pressure, insulin resistance, and total cholesterol were not significantly different between the two groups after intervention.

CONCLUSION

Synbiotic supplement may decrease waist circumference, HbA1c, LDL and TG and prevent BMI increase in patients receiving antipsychotic drugs.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT Number: IRCT20090901002394N45), Date: 26-12-2019.

What We Know About the Actual Role of Traditional Probiotics in Health and Disease

The complex relationship between probiotics and human health goes beyond their traditional function in gut health, generating considerable interest for their broad potential in disease treatment. This review explores the various functions of probiotics, highlighting their impact on the immune system, their benefits for gut and oral health, their effects on metabolic and neurological disorders, and their emerging potential in cancer therapy. We give significant importance to studying the effects of probiotics on the gut-brain axis, revealing new and non-invasive therapeutic approaches for complex neurological disorders. In addition, we expand the discussion to encompass the impact of probiotics on the gut-liver and gut-lung axes, recognizing their systemic effects and potential in treating respiratory and hepatic conditions. The use of probiotic "cocktails" to improve cancer immunotherapy outcomes indicates a revolutionary approach to oncological treatments. The review explores the specific benefits associated with various strains and the genetic mechanisms that underlie them. This study sets the stage for precision medicine, where probiotic treatments can be tailored to meet the unique needs of each patient. Recent developments in delivery technologies, including microencapsulation and nanotechnology, hold great potential for enhancing the effectiveness and accuracy of probiotic applications in therapeutic settings. This study provides a strong basis for future scientific research and clinical use, promoting the incorporation of probiotics into treatment plans for a wide range of diseases. This expands our understanding of the potential benefits of probiotics in modern medicine.

Reduction of hyperglycemia in STZ-induced diabetic mice by prophylactic treatment with heat-killed Mycobacterium aurum: possible effects on glucose utilization, mitochondrial uncoupling, and oxidative stress in liver and skeletal muscle

Background

In addition to conventional treatment and modifications in physical activity and diet, alternative strategies have been investigated to manage, prevent, or delay diabetes in humans. In this regard, one strategy has relied on the immunomodulatory properties of mycobacteria, whereby Bacillus Calmette-Guerin, an attenuated live strain of Mycobacterium bovis, has been shown to improve glycemic control in patients with diabetes and to alleviate hyperglycemia in selected murine models of diabetes. A novel heat-killed (HK) whole-cell preparation of Mycobacterium aurum (M. aurum) is currently under development as a potential food supplement; nevertheless, its potential bioactivity remains largely unknown. Thus, the present study investigated the potential prophylactic anti-diabetic effects of HK M. aurum in streptozotocin (STZ)-induced diabetic mice.

Methods

Mice were divided into three groups: the STZ-induced diabetic group was injected with a single intraperitoneal high dose of STZ, the HK M. aurum-treated diabetic group was prophylactically treated with three doses of HK M. aurum 6 weeks before STZ injection, and the control non-diabetic group was given three intradermal injections of borate-buffered saline and an intraperitoneal injection of citrate buffer. Liver lactate dehydrogenase (LDH), uncoupling protein 2 (UCP2), and glucose transporter 2 (GLUT2) and skeletal muscle LDH, UCP3, and GLUT4 protein expression levels in different mouse groups were determined by Western blot.

Results

Our results indicated that HK M. aurum did not cause any significant changes in glycemic levels of normal non-diabetic mice. Prophylactic administration of three doses of HK M. aurum to diabetic mice resulted in a significant reduction in their blood glucose levels when compared to those in control diabetic mice. Prophylactic treatment of diabetic mice with HK M. aurum significantly restored their disturbed protein expression levels of liver UCP2 and LDH as well as of skeletal muscle UCP3. On the other hand, prophylactic treatment of diabetic mice with HK M. aurum had no significant effect on their liver GLUT2 and skeletal muscle GLUT4 and LDH protein expression levels.

Conclusions

Our findings provide the first evidence that HK M. aurum possesses a hyperglycemia-lowering capacity and might support its future use as a food supplement for the amelioration of diabetes.

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.

The effects of prebiotic, probiotic or synbiotic supplementation on overweight/obesity indicators: an umbrella review of the trials' meta-analyses

Background

There is controversial data on the effects of prebiotic, probiotic, or synbiotic supplementations on overweight/obesity indicators. Thus, we aimed to clarify this role of biotics through an umbrella review of the trials' meta-analyses.

Methods

All meta-analyses of the clinical trials conducted on the impact of biotics on overweight/obesity indicators in general populations, pregnant women, and infants published until June 2023 in PubMed, Web of Sciences, Scopus, Embase, and Cochrane Library web databases included. The meta-analysis of observational and systematic review studies without meta-analysis were excluded. We reported the results by implementing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flowchart. The Assessment of Multiple Systematic Reviews-2 (AMSTAR2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological quality and quality of evidence.

Results

Overall, 97 meta-analysis studies were included. Most studies were conducted on the effect of probiotics in both genders. Consumption of prebiotic: 8-66 g/day, probiotic: 104 -1.35×1015 colony-forming unit (CFU)/day, and synbiotic: 106-1.5×1011 CFU/day and 0.5-300 g/day for 2 to 104 weeks showed a favorable effect on the overweight/obesity indicators. Moreover, an inverse association was observed between biotics consumption and overweight/obesity risk in adults in most of the studies. Biotics did not show any beneficial effect on weight and body mass index (BMI) in pregnant women by 6.6×105-1010 CFU/day of probiotics during 1-25 weeks and 1×109-112.5×109 CFU/capsule of synbiotics during 4-8 weeks. The effect of biotics on weight and BMI in infants is predominantly non-significant. Prebiotics and probiotics used in infancy were from 0.15 to 0.8 g/dL and 2×106-6×109 CFU/day for 2-24 weeks, respectively.

Conclusion

It seems biotics consumption can result in favorable impacts on some anthropometric indices of overweight/obesity (body weight, BMI, waist circumference) in the general population, without any significant effects on birth weight or weight gain during pregnancy and infancy. So, it is recommended to intake the biotics as complementary medications for reducing anthropometric indices of overweight/obese adults. However, more well-designed trials are needed to elucidate the anti-obesity effects of specific strains of probiotics.

The Role of Probiotics in Managing Glucose Homeostasis in Adults with Prediabetes: A Systematic Review and Meta-Analysis

Methods

The Preferred Reporting Items for Systematic Reviews and Analysis checklist was used. A comprehensive literature search of the PubMed, Embase, and Cochrane Library databases was conducted through August 2022 to assess the impact of probiotics on blood glucose, lipid, and inflammatory markers in adults with prediabetes. Data were pooled using a random effects model and were expressed as standardized mean differences (SMDs) and 95% confidence interval (CI). Heterogeneity was evaluated and quantified as I2.

Results

Seven publications with a total of 550 patients were included in the meta-analysis. Probiotics were found to significantly reduce the levels of glycosylated hemoglobin (HbA1c) (SMD -0.44; 95% CI -0.84, -0.05; p = 0.03; I2 = 76.13%, p < 0.001) and homeostatic model assessment of insulin resistance (HOMA-IR) (SMD -0.27; 95% CI -0.45, -0.09; p < 0.001; I2 = 0.50%, p = 0.36) and improve the levels of high-density lipoprotein cholesterol (HDL) (SMD -8.94; 95% CI -14.91, -2.97; p = 0.003; I2 = 80.24%, p < 0.001), when compared to the placebo group. However, no significant difference was observed in fasting blood glucose, insulin, total cholesterol, triglycerides, low-density lipoprotein cholesterol, interleukin-6, tumor necrosis factor-α, and body mass index. Subgroup analyses showed that probiotics significantly reduced HbA1c in adults with prediabetes in Oceania, intervention duration of ≥3 months, and sample size <30.

Conclusions

Collectively, our meta-analysis revealed that probiotics had a significant impact on reducing the levels of HbA1c and HOMA-IR and improving the level of HDL in adults with prediabetes, which indicated a potential role in regulating blood glucose homeostasis. However, given the limited number of studies included in this analysis and the potential for bias, further large-scale, higher-quality randomized controlled trials are needed to confirm these findings. This trial is registered with CRD42022358379.

A Narrative Review on Strategies for the Reversion of Prediabetes to Normoglycemia: Food Pyramid, Physical Activity, and Self-Monitoring Innovative Glucose Devices

In 2019, "Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report" was published. This consensus report, however, did not provide an easy way to illustrate to subjects with prediabetes (SwPs) how to follow a correct dietary approach. The purpose of this review is to evaluate current evidence on optimum dietary treatment of SwPs and to provide a food pyramid for this population. The pyramid built shows that everyday consumption should consist of: whole-grain bread or potatoes eaten with their skins (for fiber and magnesium) and low glycemic index carbohydrates (GI < 55%) (three portions); fruit and vegetables (5 portions), in particular, green leafy vegetables (for fiber, magnesium, and polyphenols); EVO oil (almost 8 g); nuts (30 g, in particular, pistachios and almonds); three portions of dairy products (milk/yogurt: 300-400 g/day); mineral water (almost 1, 5 L/day for calcium intake); one glass of wine (125 mL); and three cups of coffee. Weekly portions should include fish (four portions), white meat (two portions), protein plant-based food (four portions), eggs (egg portions), and red/processed meats (once/week). At the top of the pyramid, there are two pennants: a green one means that SwPs need some personalized supplementation (if daily requirements cannot be satisfied through diet, vitamin D, omega-3, and vitamin B supplements), and a red one means there are some foods and factors that are banned (simple sugar, refined carbohydrates, and a sedentary lifestyle). Three to four times a week of aerobic and resistance exercises must be performed for 30-40 min. Finally, self-monitoring innovative salivary glucose devices could contribute to the reversion of prediabetes to normoglycemia.

Effects of probiotic administration on overweight or obese children: a meta-analysis and systematic review

BACKGROUND

This paper aimed to examine the effects of probiotics on eight factors in overweight or obese children by meta-analysis, namely, body mass index (BMI), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), adiponectin, leptin and tumor necrosis factor-α (TNF-α) and summarize the mechanisms of action of probiotics based on the existing researches.

METHODS

Six databases (PubMed, Web of Science, Embase, Cochrane Library, SinoMed and CNKI) were searched until March 2023. Review Manager 5.4 was used for meta-analysis. The data were analysed using weighted mean differences (WMDs) or standardized mean differences (SMDs) under a fixed effect model or random effect model to observe the effects of probiotic administration on the included indicators.

RESULTS

Four publications with a total of 206 overweight or obesity children were included. According to the meta-analysis, probiotics were able to significantly decrease the levels of HDL-C (MD, 0.06; 95% CI 0.03, 0.09; P = 0.0001), LDL-C (MD, - 0.06; 95% CI - 0.12, - 0.00; P = 0.04), adiponectin (MD, 1.39; 95% CI 1.19, 1.59; P < 0.00001), leptin (MD, - 2.72; 95% CI - 2.9, - 2.54; P < 0.00001) and TNF-α (MD, - 4.91; 95% CI - 7.15, - 2.67; P < 0.0001) compared to those in the placebo group. Still, for BMI, the palcebo group seemed to be better than the probiotic group (MD, 0.85; 95% CI 0.04, 1.66; P = 0.04). TC (MD, - 0.05; 95% CI - 0.12, 0.02; P = 0.14) and TG (MD, - 0.16; 95% CI - 0.36, 0.05; P = 0.14) were not different between two groups.

CONCLUSIONS

This review drew that probiotics might act as a role in regulating HDL-C, LDL-C, adiponectin, leptin and TNF-α in overweight or obesity children. Additionally, our systematic review yielded that probiotics might regulate lipid metabolism and improve obese associated symptoms by some paths. This meta-analysis has been registered at PROSPERO with ID: CRD42023408359.

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.

The Influence of Gut Microbial Species on Diabetes Mellitus

Diabetes mellitus (DM) is a metabolic disorder with an alarming incidence rate and a considerable burden on the patient's life and health care providers. An increase in blood glucose level and insulin resistance characterizes it. Internal and external factors such as urbanization, obesity, and genetic mutations could increase the risk of DM. Microbes in the gut influence overall health through immunity and nutrition. Recently, more studies have been conducted to evaluate and estimate the role of the gut microbiome in diabetes development, progression, and management. This review summarizes the current knowledge addressing three main bacterial species: Bifidobacterium adolescentis, Bifidobacterium bifidum, and Lactobacillus rhamnosus and their influence on diabetes and its underlying molecular mechanisms. Most studies illustrate that using those bacterial species positively reduces blood glucose levels and activates inflammatory markers. Additionally, we reported the relationship between those bacterial species and metformin, one of the commonly used antidiabetic drugs. Overall, more research is needed to understand the influence of the gut microbiome on the development of diabetes. Furthermore, more efforts are required to standardize the model used, concentration ranges, and interpretation tools to advance the field further.