Multi-species synbiotic supplementation increased fecal short chain fatty acids and anti-inflammatory cytokine interleukin-10 in adult men with dyslipidemia; A randomized, double-blind, clinical trial.

BACKGROUND: Mounting evidence revealed that an imbalance of Gut Microbiota (GM) leads to metabolic disorders. Synbiotics through regulation of GM composition can be an effective intervention in the management of metabolic diseases. This study aimed to investigate the effects of multi-species synbiotic supplementation on serum interleukin10 (IL-10) and fecal Short Chain Fatty Acids (SCFAs) in patients with dyslipidemia. METHODS: In this double-blind, randomized, placebo-controlled clinical trial, fifty-six adult men with dyslipidemia were randomly allocated to intervention and control groups and received either synbiotic or placebo powder twice a day for 12 weeks. Each synbiotic sachet contained 6 species of probiotic microorganisms with a total dose of 3 × 1010 Colony Forming Unit (CFU) and 5 gr inulin and Fructooligosaccharide (FOS) as prebiotics. Blood and stool samples were collected at the baseline and end of the study. Dietary intake, physical activity, anthropometric measurements, serum IL-10, and fecal SCFAs were assessed before and after the intervention. RESULT: There were no significant differences between the baseline characteristics of patients in the two groups. Serum IL-10 was increased in the synbiotic group (p < 0.0001). Moreover, synbiotic supplementation increased fecal concentration of acetate (p < 0.0001), butyrate (p = 0.043), propionate (p < 0.0001), and valerate (p < 0.026). A significant positive correlation was observed between the changes in fecal butyrate level and serum IL-10 concentration in the control group (r = 0.48, p = 0.01). CONCLUSIONS: A Twelve-week synbiotic supplementation increased fecal SCFAs and improved inflammation in adult men with dyslipidemia.

The effects of vitamin C supplementation on glycemic control in patients with type 2 diabetes: A systematic review and meta-analysis.

BACKGROUND AND AIM: It has been suggested that taking vitamin C supplements may improve glycemic control in patients with type 2 diabetes mellitus (T2DM). However, there has not been a thorough evaluation of the actual impact or certainty of the findings. This systematic review and meta-analysis was conducted to determine the effect of vitamin C supplementation on glycemic profile in T2DM patients. METHODS: A systematic search was performed across online databases including Scopus, Web of Science, and PubMed/Medline to identify relevant randomized controlled trials (RCTs) published until July 2022. A random-effects model was applied for the meta-analysis. RESULTS: The present meta-analysis included a total of 22 RCTs with 1447 patients diagnosed with T2DM.A pooled analysis revealed a significant decrease in levels of serum hemoglobin A1c (HbA1c), fasting insulin, and fasting blood glucose (FBG) in vitamin C-treated T2DM patients compared with their untreated counterparts. The dose-response evaluation displayed a substantial linear association between the intervention duration and changes in serum HbA1c levels. However, the analysis did not demonstrate any significant effect of vitamin C on serum values of homeostasis model assessment of insulin resistance(HOMA-IR) in diabetic patients. Subgroup analyses indicated that high-dose vitamin C administration (≥1000 mg/d) considerably decreased serum HOMA-IR levels. CONCLUSION: These findings suggest that long-term (≥12 weeks) and high-dose vitamin C supplementation (≥1000 mg/d) may ameliorate glycemic profile in T2DM patients. However, additional high-quality RCTs are necessary to validate these results.

The effect of nigella sativa supplementation on cardiometabolic outcomes in patients with non-alcoholic fatty liver: A randomized double-blind, placebo-controlled trial.

BACKGROUND AND PURPOSE: Non-alcoholic fatty liver disease (NAFLD) is one of the metabolic disturbances associated with liver cell inflammation. Nigella sativa (N.sativa) is a widely used medicinal plant known for its anti-inflammatory, antimicrobial, antioxidant, and hepato-protective properties. This study aimed to assess the effect of supplementation of N. sativa oil on plasma levels of adiponectin, leptin, and blood pressure (BP) in patients diagnosed with NAFLD. MATERIALS AND METHODS: This randomized, double-blind, placebo-controlled clinical trial was conducted on 44 NAFLD patients. Participants were randomly assigned to two groups (n = 22/group); the experimental group received 1000 mg of N. sativa oil per day, while the control group received a placebo for eight weeks. The primary outcome measures were serum levels of adiponectin, leptin, and systolic and diastolic blood pressure measured at the baseline and the end of the intervention. RESULTS: After eight weeks of supplementation with N. sativa oil, no statistically significant differences were found in serum levels of adiponectin (p = 0.40), leptin (p = 0.89), systolic BP (p = 0.13), and diastolic BP (p = 0.09) between the two groups. Furthermore, after supplementation with N. sativa, no significant changes were observed in leptin (p = 0.07), adiponectin (p = 0.13), systolic BP (p = 0.82), and diastolic BP (p = 0.38) within the two groups. CONCLUSION: These results indicate that administration of N. sativa oil 1000 mg/day for 8 weeks has no favorable effect on cardiometabolic measures in NAFLD patients. Further studies with higher dosage over a longer period are needed to investigate whether this effect is dose- and time-dependent.

Effect of flaxseed supplementation on lipid profile: An updated systematic review and dose-response meta-analysis of sixty-two randomized controlled trials.

Raised plasma lipids are one the most important risk factors for cardiovascular disease. Flaxseed contains considerable amounts of α-linolenic acid, phenolic compounds, and lignans, which each have the capacity to reduce circulating lipid concentrations. This study aimed to systematically review current evidence to identify the potential effects of flaxseed supplementation on blood lipid profiles using a meta-analysis of randomized controlled trials (RCTs). PubMed, Scopus, Web of Science, and Google Scholar databases were searched for publications between January 1900 and May 2019. Weighted mean differences (WMDs) were analyzed using a random-effects model. The Cochrane Collaboration tool was also used to assess the risk of bias of the studies included. Sixty-two RCTs with a total of 3772 participants met the eligibility criteria. Our analysis showed that flaxseed supplementation significantly reduced total cholesterol (TC) (WMD = -5.389 mg/dL; 95% CI: -9.483, -1.295, p = 0.010), triglyceride (TG) (WMD = -9.422 mg/dL; 95% CI: -15.514, -3.330, p = 0.002), and low-density lipoprotein cholesterol (LDL-C) (WMD = -4.206 mg/dl; 95% CI: -7.260, -1.151, p = 0.007) concentrations. However, it had no effects on high-density lipoprotein cholesterol (WMD = 0.047 mg/dl; 95% CI: -0.777, 0.872, p = 0.910). This meta-analysis suggested that flaxseed supplementation improves serum TC, TG, and LDL-C, which could delay the progression of heart disease. Further studies with large-scale and better design are now needed to confirm these results.

The influence of vitamin D supplementation on IGF-1 levels in humans: A systematic review and meta-analysis.

BACKGROUND: Inconsistencies exist with regard to influence of vitamin D supplementation on IGF-1 levels. The inconsistencies could be attributed to several factors, such as dosage and duration of intervention, among others. To address these inconsistencies, this study was conducted to determine the impact of vitamin D supplementation on IGF-1 levels through a systematic review and meta-analysis of randomized controlled trials (RCTs). METHODS: A comprehensive systematic search was carried out in PubMed/MEDLINE, Web of Science, SCOPUS and Embase for RCTs that investigated the impact of vitamin D intake on circulating IGF-1 levels from inception until June 2019. Weighted mean difference (WMD) with the 95 % CI were applied for estimating combined effect size. Subgroup analysis was performed to specify the source of heterogeneity among studies. RESULTS: Pooled results from eight studies demonstrated an overall non-significant increase in IGF-1 following vitamin D supplementation (WMD: 4 ng/ml, 95 % CI: -4 to 11). However, a significant degree of heterogeneity among studies was observed (I2 = 66 %). The subgroup analyses showed that vitamin D dosage of ≤1000 IU/day (WMD: 10 ng/ml) significantly increased IGF-1 compared to the vitamin D dosage of <1000 IU/day (WMD: -1 ng/ml). Moreover, intervention duration ≤12 weeks (WMD: 11 ng/ml) significantly increased IGF-1 compared to intervention duration <12 weeks (WMD: -3 ng/ml). In the epidemiological cohort study, participants under 60 years of age with a higher dietary vitamin D intake had significantly higher IGF-1 levels when compared to those with lower dietary vitamin D intake in second categories. CONCLUSION: The main results indicate a non-significant increase in IGF-1 following vitamin D supplementation. Additionally, vitamin D dosages of <1000 IU/day and intervention durations of <12 weeks significantly raised IGF-1 levels.

The effect of green-coffee extract supplementation on obesity: A systematic review and dose-response meta-analysis of randomized controlled trials.

BACKGROUND: Given that the most recent systematic review investigating Green-Coffee Extract (GCE) as a weight loss facilitator was nearly a decade ago and that the authors reported there no consensus on the effect of GCE/CGA (Chlorogenic acids) on body composition indices, a comprehensive systematic review and dose-response meta-analysis of all available randomized controlled trial (RCTs) was undertaken to examine the effect of GCE and CGA intervention on body weight (BW), body mass index (BMI) and waist circumference (WC) in adults. METHODS: We conducted a systematic search of all available randomized controlled trials (RCTs) performed up to June 2019 in the following electronic databases: PubMed, Scopus and Google Scholar. RCTs that investigated the effect GCE/CGA Supplementation on BW, BMI and WC in adults were included for final analysis. The pooled weight mean difference (WMD) of included studies was estimated using a random-effects model. RESULTS: A total of 13 articles with 16 RCTs were included in the meta-analysis. Results revealed significant reduction in BMI (WMD: -0.403 kg/m2, 95% CI: -0.800, -0.005, p = 0.047) and no significant change in BW (WMD: -0.585 kg, 95% CI: -1.498, 0.329, p = 0.210) and WC (WMD: -0.847 cm, 95% CI: -1.764, 0.071, p = 0.070). In the subgroup analysis, studies that were conducted on baseline BMI ≥25 kg/m2 revealed a significant greater reduction in body weight and BMI than those performed on baseline BMI <25 kg/m2. Moreover, short supplementation periods of less than 4 weeks had no effect. CONCLUSION: The results of current meta-analysis study support the use of GCE supplementation for the improvement of obesity indices, with sub-group analysis highlighting greater improvements in individuals with a starting BMI ≥25 kg/m2.