Can modulation of gut microbiota affect anthropometric indices in patients with non-alcoholic fatty liver disease? An umbrella meta-analysis of randomized controlled trials.

Background and aim: Modulating the gut microbiota population by administration of probiotics, prebiotics, and synbiotics has shown to have a variety of health benefits in different populations, particularly those with metabolic disorders. Although the promising effects of these compounds have been observed in the management of patients with non-alcoholic fatty liver disease (NAFLD), the exact effects and the mechanisms of action are yet to be understood. In the present study, we aimed to evaluate how gut microbiota modulation affects anthropometric indices of NAFLD patients to achieve a comprehensive summary of current evidence-based knowledge. Methods: Two researchers independently searched international databases, including PubMed, Scopus, and Web of Science, from inception to June 2023. Meta-analysis studies that evaluated the effects of probiotics, prebiotics, and synbiotics on patients with NAFLD were entered into our umbrella review. The data regarding anthropometric indices, including body mass index, weight, waist circumference (WC), and waist-to-hip ratio (WHR), were extracted by the investigators. The authors used random effect model for conducting the meta-analysis. Subgroup analysis and sensitivity analysis were also performed. Results: A total number of 13 studies were finally included in our study. Based on the final results, BMI was significantly decreased in NAFLD patients by modulation of gut microbiota [effect size (ES): -0.18, 05% CI: -0.25, -0.11, P<0.001]; however, no significant alteration was observed in weight and WC (ES: -1.72, 05% CI: -3.48, 0.03, P=0.055, and ES: -0.24, 05% CI: -0.75, 0.26, P=0.353, respectively). The results of subgroup analysis showed probiotics had the most substantial effect on decreasing BMI (ES: -0.77, 95% CI: -1.16, -0.38, P<0.001) followed by prebiotics (ES: -0.51, 95% CI: -0.76, -0.27, P<0.001) and synbiotics (ES: -0.12, 95% CI: -0.20, -0.04, P=0.001). Conclusion: In conclusion, the present umbrella meta-analysis showed that although modulation of gut microbiota by administration of probiotics, prebiotics, and synbiotics had promising effects on BMI, no significant change was observed in the WC and weight of the patients. No sufficient data were available for other anthropometric indices including waist-to-hip ratio and waist-to-height ratio and future meta-analyses should be done in this regard.

The effects of gut microbiome manipulation on glycemic indices in patients with non-alcoholic fatty liver disease: a comprehensive umbrella review.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a significant risk factor for non-alcoholic fatty liver disease (NAFLD). Increased fasting blood sugar (FBS), fasting insulin (FI), and insulin resistance (HOMA-IR) are observed in patients with NAFLD. Gut microbial modulation using prebiotics, probiotics, and synbiotics has shown promise in NAFLD treatment. This meta-umbrella study aimed to investigate the effects of gut microbial modulation on glycemic indices in patients with NAFLD and discuss potential mechanisms of action. METHODS: A systematic search was conducted in PubMed, Web of Science, Scopus, and Cochrane Library until March 2023 for meta-analyses evaluating the effects of probiotics, prebiotics, and synbiotics on patients with NAFLD. Random-effect models, sensitivity analysis, and subgroup analysis were employed. RESULTS: Gut microbial therapy significantly decreased HOMA-IR (ES: -0.41; 95%CI: -0.52, -0.31; P < 0.001) and FI (ES: -0.59; 95%CI: -0.77, -0.41; P < 0.001). However, no significant effect was observed on FBS (ES: -0.17; 95%CI: -0.36, 0.02; P = 0.082). Subgroup analysis revealed prebiotics had the most potent effect on HOMA-IR, followed by probiotics and synbiotics. For FI, synbiotics had the most substantial effect, followed by prebiotics and probiotics. CONCLUSION: Probiotics, prebiotics, and synbiotics administration significantly reduced FI and HOMA-IR, but no significant effect was observed on FBS.

The association between various viral infections and multiple sclerosis: An umbrella review on systematic review and meta-analysis.

Multiple Sclerosis (MS) is one of the immune-mediated demyelinating disorders. Multiple components, including the environment and genetics, are possible factors in the pathogenesis of MS. Also, it can be said that infections are a key component of the host's response to MS development. Finally, we evaluated the relationship between different pathogens and MS disease in this umbrella research. We systematically collected and analysed multiple meta-analyses focused on one particular topic. We utilised the Scopus, PubMed, and Web of Science databases starting with inception until 30 May 2023. The methodological quality of the analysed meta-analysis has been determined based on Assessing the Methodological Quality of Systematic Reviews 2 and Grade, and graph construction and statistical analysis were conducted using Comprehensive Meta-Analysis. The Confidence Interval of effect size was 95% in meta-analyses, and p < 0.05 indicated a statistically meaningful relationship. The included studies evaluated the association between MS and 12 viruses containing SARS-CoV-2, Epstein-Barr virus (EBV), Hepatitis B virus, varicella-zoster virus (VZV), human herpesvirus 6 (HHV-6), HHV-7, HHV-8, HSV-1, HSV-2, Cytomegalovirus, Human Papillomavirus, and influenza. SARS-CoV-2, with a 3.74 odds ratio, has a significantly more potent negative effect on MS among viral infections. After that, EBV, HHV-6, HSV-2, and VZV, respectively, with 3.33, 2.81, 1.76, and 1.72 odds ratios, had a significantly negative relationship with MS (p < 0.05). Although the theoretical evidence mostly indicates that EBV has the greatest effect on MS, recent epidemiological studies have challenged this conclusion and put forward possibilities that SARS-CoV-2 is the culprit. Hence, it was necessary to investigate the effects of SARS-CoV-2 and EBV on MS.

Family history of cancer as a potential risk factor for colorectal cancer in EMRO countries: a systematic review and meta-analysis.

The current meta-analysis aims to investigate the existing articles that evaluated the implications of a positive family history of cancer on the risk of colorectal cancer (CRC) within the EMRO countries. We employed PubMed, Scopus, and Web of Science as search databases for this study. To assess the quality of the selected articles, we utilized the Newcastle-Ottawa (NCO) checklist. In comparing the impact of a family history of cancer between the case and control groups, we computed the odds ratio (OR) along with its corresponding 95% confidence interval (CI). Finally, 27 articles were selected for meta-analysis. The result of the meta-analysis showed a significant association between the presence of a family history of CRC or any cancers and CRC (OR 2.21; 95% CI 1.54-3.17; P < 0.001, OR 1.76; 95% CI 1.27-2.42; P = 0.001, respectively). Our findings underscore the critical importance of timely screening and early identification for individuals with a family history of cancer. By fostering close coordination among healthcare facilities and actively promoting the adoption of screening methods for early detection, we have the potential to significantly reduce both mortality rates and financial burdens of CRC on the general public, ultimately leading to enhanced patient outcomes.

Association between smoking and colorectal cancer in Eastern Mediterranean Regional Office (EMRO): A systematic review and meta-analysis.

Background: Smoking poses a significant risk for colorectal cancer (CRC), considered the third leading reason for cancer-related deaths worldwide. However, there has been limited research on the relationship between smoking and CRC in the Eastern Mediterranean Regional Office (EMRO). Therefore, a meta-analysis was conducted to combine available data and gain a comprehensive understanding of the relationship between smoking and CRC in EMRO. Methods: Two independent researchers searched PubMed, Scopus, and Web of Science until December 2022. The included studies were checked for risk of bias administering the Newcastle-Ottawa scale. Heterogeneity was evaluated using I2 statistics and the Cochrane test. Publication bias was determined through funnel plot analysis and Egger's regression test. Additionally, a meta-regression analysis explored the impact of a country's Human Development Index (HDI) on the relationship between smoking and CRC. Results: The final analysis included 26 studies, revealing a significant association between smoking and CRC (OR = 1.40; 95% CI: 1.11 - 1.78; P = 0.004). Moreover, smoking had a more pronounced adverse effect on CRC in countries with higher HDIs compared to those with lower HDIs (OR = 1.30; 95% CI: 0.99 - 1.71; P = 0.054). Conclusions: Our findings underscore the importance of implementing smoking cessation programs and policies in EMRO countries, as they demonstrate a positive relationship between smoking and the risk of CRC. Furthermore, the results suggest that a country's level of human development may influence the association between smoking and CRC. Further research is needed to investigate this potential connection and develop targeted public health interventions.