The effectiveness of probiotics as an adjunct therapy in patients under mechanical ventilation: an umbrella systematic review and meta-analysis.

The literature regarding the role of probiotics in critically ill patients who have undergone mechanical ventilation (MV) is unclear; therefore, this umbrella systematic review and meta-analysis was carried out to clarify the effects of probiotics on the clinical outcomes of mechanically ventilated patients. The Scopus, PubMed/Medline, ISI Web of Science, and Google Scholar online databases were searched up to February 2023. All meta-analyses evaluating the impact of probiotics in patients under MV were considered eligible. The assessment of multiple systematic reviews (AMSTAR) questionnaire was used to evaluate the quality of the studies. Data were pooled using the random-effects approach. Thirty meta-analyses and nine clinical outcomes were re-analyzed. Probiotics significantly decreased ventilator-associated pneumonia (VAP) incidence, nosocomial infections, intensive care unit (ICU) length of stay, hospital length of stay, ICU mortality, hospital mortality, MV duration, duration of antibiotic use, and diarrhea. The obtained results of the current umbrella meta-analysis indicate that probiotic administration could be considered an adjunct therapy for critically ill patients; however, no specific probiotic treatment regimen can be recommended due to the diverse probiotics used in the included meta-analyses. The following microorganisms were used at various doses and combinations throughout the studies: Lacticaseibacillus casei, Lactiplantibacillus plantarum, L. acidophilus, L. delbrueckii, L. bulgaricus, Bifidobacterium longum, B. breve, B. salivarius, Pediococcus pentosaceus, Lactococcus raffinolactis, B. infantis, B. bifidum, Streptococcus thermophilus, Ligilactobacillus salivarius, L. lactis, B. lactis, Saccharomyces boulardii, L. rhamnosus GG, L. johnsonii, L. casei, S. faecalis, Clostridium butyricum, Bacillus mesentericus, L. sporogenes, S. boulardii, L. paracasei, B. subtilis, and Enterococcus faecium.

The efficacy of curcumin in relieving osteoarthritis: A meta-analysis of meta-analyses.

Osteoarthritis (OA) is one of the most prevalent degenerative joint diseases. Several meta-analyses have shown that curcumin could improve the function of the knee and alleviate pain in OA, while some meta-analyses demonstrate controversial results. Hence, we assessed curcumin's effects on knee OA in an umbrella meta-analysis. PubMed, Scopus, Embase, and Web of Science databases were employed to find English-language meta-analyses of randomized controlled trials investigating the effect of curcumin supplementation on OA outcomes up to September 2023. The visual analog scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, function, and stiffness scales were analyzed. Effect sizes and 95% confidence intervals were utilized to obtain the overall effect size. A random-effects model was applied to perform the meta-analysis. Heterogeneity was determined by I2 statistics and the Cochrane Q-test. The pooled effect of the 11 included meta-analyses showed that curcumin could significantly decrease the VAS score (weighted mean difference [WMD] and standardized mean difference [SMD]), WOMAC-total (SMD and WMD), WOMAC-Function (SMD and WMD), WOMAC-Pain (SMD), and WOMAC-Stiffness scores (SMD) (p ≤ 0.001, ≤0.001, ≤0.001, 0.007, ≤0.001, 0.002, ≤0.001, ≤0.001, respectively). The results strongly support curcuminoid supplementation in relieving pain, improving joint mobility and stiffness, and shortening medication usage of OA patients.

The role of vitamin D in outcomes of critical care in COVID-19 patients: evidence from an umbrella meta-analysis of interventional and observational studies.

OBJECTIVES: Several meta-analyses have suggested the beneficial effect of vitamin D on patients infected with severe acute respiratory syndrome coronavirus-2. This umbrella meta-analysis aims to evaluate influence of vitamin D supplementation on clinical outcomes and the mortality rate of COVID-19 patients. DESIGN: Present study was designed as an umbrella meta-analysis. The following international databases were systematically searched till March 2023: Web of Science, PubMed, Scopus, and Embase. SETTINGS: Random-effects model was employed to perform meta-analysis. Using AMSTAR critical evaluation tools, the methodological quality of the included meta-analyses was evaluated. PARTICIPANTS: Adult patients suffering from COVID-19 were studied. RESULTS: Overall, 13 meta-analyses summarising data from 4 randomised controlled trial and 9 observational studies were identified in this umbrella review. Our findings revealed that vitamin D supplementation and status significantly reduced mortality of COVID-19 [Interventional studies: (ES = 0·42; 95 % CI: 0·10, 0·75, P < 0·001; I2 = 20·4 %, P = 0·285) and observational studies (ES = 1·99; 95 % CI: 1·37, 2·62, P < 0·001; I2 = 00·0 %, P = 0·944). Also, vitamin D deficiency increased the risk of infection and disease severity among patients. CONCLUSION: Overall, vitamin D status is a critical factor influencing the mortality rate, disease severity, admission to intensive care unit and being detached from mechanical ventilation. It is vital to monitor the vitamin D status in all patients with critical conditions including COVID patients.

Corrigendum: Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis.

[This corrects the article DOI: 10.3389/fnut.2023.1117387.].

The Effect of Vitamin D Supplementation on Lipid Profiles: an Umbrella Review of Meta-Analyses.

According to published meta-analyses, vitamin D exerts different beneficial effects in preventing and controlling risk factors associated with noncommunicable chronic diseases; however, the results are still conflicting. The purpose of this umbrella meta-analysis was to investigate the effect of vitamin D supplementation on low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol (TC), and triglyceride (TG) as components of the lipid profile. PubMed, Scopus, Web of Science, and Cochrane Database of Systematic Reviews were systematically searched for meta-analyses of randomized controlled trials. The umbrella meta-analysis followed the PRISMA guidelines. The random-effects model was employed to estimate the overall effect size (ES). Overall, 25 meta-analyses were included. In the standardized mean difference analysis, vitamin D significantly decreased TG (ES: -0.15; 95% CI: -0.23, -0.08; P ≤ 0.001) and TC levels (ES: -0.17; 95% CI: -0.23, -0.11; P ≤ 0.001) and increased HDL levels (ES: 0.08; 95% CI: 0.01, 0.15; P = 0.025). In the weighted mean difference analysis, vitamin D significantly decreased only TG levels (ES: -4.63 mg/dL; 95% CI: -7.70, -1.57; P = 0.003). The present study supports that vitamin D supplementation could be considered a beneficial adjuvant therapy in managing lipid profile levels, especially in individuals with vitamin D deficiency. This systematic review was registered in PROSPERO as CRD42022306334.

Remarkable impacts of probiotics supplementation in enhancing of the antioxidant status: results of an umbrella meta-analysis.

Introduction: Numerous meta-analyses have demonstrated the beneficial effects of probiotics on oxidative stress biomarkers, although some studies have contradictory results. Therefore, the current research was conducted to obtain a precise and definite understanding on the impact of probiotics on oxidative stress biomarkers in adults. Methods: We conducted a comprehensive systematic search of results on Scopus, PubMed, Embase, Web of Science, and Google Scholar dating up to March 2022. Fifteen meta-analyses were included in this umbrella meta-analysis. The random-effects model was employed to obtain the overall effect size. Subgroup analyses were carried out based on supplementation dosage and duration, mean age, and study population. Results: Our results indicated that probiotics supplementation meaningfully decreased serum malondialdehyde (MDA) (ESWMD = -0.56, 95% CI: -0.72, -0.39; p < 0.001, and ESSMD = -0.50, 95% CI: -0.66, -0.34; p < 0.001). Moreover, the findings showed that probiotics resulted in a significant increase in total antioxidant capacity (TAC) (ESWMD = 29.18, 95% CI: 16.31, 42.04; p < 0.001, and ESSMD = 0.25, 95% CI: 0.02, 0.47; p = 0.032), total glutathione (GSH) (ESWMD: 30.65; 95% CI: 16.94, 44.35, p < 0.001), and nitric oxide (NO) (ESWMD: 1.48; 95% CI: 0.31, 2.65, p = 0.013; I2 = 51.7%, p = 0.043). Discussion: Probiotics could be considered a strong agent in the reinforcement of antioxidant status and preventing the incidence of chronic diseases.

The Impact of Vitamin D Supplementation on Improving Blood Pressure: Evidence Obtained From an Umbrella Meta-analysis.

PURPOSE: The results of meta-analyses regarding the effect of vitamin D on blood pressure are conflicting. The present umbrella meta-analysis was conducted to provide definite and conclusive results. METHODS: Systematically, Scopus, EMBASE, PubMed, and Web of Science databases and Google Scholar were searched for relevant literature published up to July 2022. All meta-analyses of clinical trials addressing the effect of vitamin D on blood pressure were included. Random effects analysis was performed to obtain the overall effect size based on the standardized mean differences (SMDs) and weighted mean differences (WMDs) separately. The quality of included meta-analyses was assessed by using the Measurement Tool for Assessing Multiple Systematic Reviews 2 questionnaire. FINDINGS: Overall, 21 meta-analyses were enrolled in the umbrella review. The results indicated that systolic blood pressure was significantly reduced after the intervention based on WMD effect size analysis (ESWMD = -0.69 mm Hg; 95% CI, -1.35 to -0.04 [P < 0.038]; I2 = 46.7%, P = 0.021); however, no considerable impact was observed based on analysis of SMD effect sizes (ESSMD = -0.05 mm Hg; 95% CI, -0.24 to 0.14; P = 0.615). Also, vitamin D supplementation indicated a significant improvement in diastolic blood pressure based on WMD effect sizes (ESWMD = -0.66 mm Hg; 95% CI, -1.05 to -0.27 [P < 0.001]; I2 = 56.4%, P = 0.004) but not SMD analysis (ESSMD = -0.04 mm Hg; 95% CI, -0.13 to 0.04 [P = 0.328]; I2 = 53.4%, P = 0.057). IMPLICATIONS: Based on obtained evidence, vitamin D could be considered an efficient adjuvant for improving blood pressure.

The effectiveness of treatment with probiotics in Helicobacter pylori eradication: results from an umbrella meta-analysis on meta-analyses of randomized controlled trials.

Background and aims: The purpose of this umbrella meta-analysis was to quantitatively summarize meta-analyses of randomized controlled trial (RCT) studies regarding the effects of probiotic supplementation on Helicobacter pylori (H. pylori) eradication. Methods: A thorough search of the electronic databases including PubMed, Web of Science, Embase, Scopus, and Google Scholar was carried out from the inception up to May 2022. For the evaluation of overall effect sizes, the pooled relative risk (RR) or odds ratio (OR) and their corresponding 95% confidence intervals (CI) were calculated. The random-effects model was used for the meta-analysis. Results: Overall, 18 eligible studies (47 278 participants in total) were included in the study. The findings revealed that probiotics have a beneficial impact on H. pylori eradication (pooled ESRR: 1.13; 95% CI: 1.11, 1.14, p < 0.01, and ESOR = 1.86, 95% CI: 1.70, 2.03, p < 0.01). Greater effects on H. pylori eradication were observed when higher doses (>10 × 1010 CFU) and mixed strains were supplemented. Conclusion: The present umbrella meta-analysis suggests that supplementation with probiotics may be considered as an efficient approach to ameliorate H. pylori complications, particularly probiotics with higher CFUs and mixed strains.

Dietary pattern in autism increases the need for probiotic supplementation: A comprehensive narrative and systematic review on oxidative stress hypothesis.

Autism spectrum disorders (ASDs) are associated with specific dietary habits, including limited food selection and gastrointestinal problems, resulting in an altered gut microbiota. Autistic patients have an elevated abundance of certain gut bacteria associated with increased oxidative stress in the gastrointestinal tract. Probiotic supplementation has been shown to decrease oxidative stress in a simulated gut model, but the antioxidant effects of probiotics on the oxidative stress of the gut in autistic patients have not been directly studied. However, it is speculated that probiotic supplementation may help decrease oxidative stress in the gastrointestinal tract of autistic patients due to their specific dietary habits altering the microbiota. PubMed, Scopus and Web of Science databases and Google Scholar were searched up to May 2023. This systematic-narrative review aims to present the latest evidence regarding the changes in eating habits of autistic children which may further increase the gut microbiota induced oxidative stress. Additionally, this review will assess the available literature on the effects of probiotic supplementation on oxidative stress parameters.

The effect of cinnamon supplementation on glycemic control in patients with type 2 diabetes or with polycystic ovary syndrome: an umbrella meta-analysis on interventional meta-analyses.

BACKGROUND: Several meta-analyses reported glycemic-lowering effects of cinnamon, while others reported conflicting findings. In the present study, we aimed to perform an umbrella meta-analysis of previous interventional meta-analyses on the effects of cinnamon on glycemic control in patients with type 2 diabetes (T2D) or with polycystic ovary syndrome (PCOS). METHODS: Relevant studies were searched in PubMed, Scopus, EMBASE, Web of Science, and Google Scholar up to June 2022. Meta-analyses of randomized clinical trials (RCTs) investigating the effects of cinnamon on glycemic indices including fasting plasma glucose (FPG), homeostatic model assessment for insulin resistance (HOMA-IR), insulin, and hemoglobin A1C (HbA1c) were included. Random-effects models were used to perform the umbrella meta-analysis and pool the weighted mean difference (WMD) or standardized mean difference (SMD) and their 95% confidence intervals (CI). RESULTS: Overall, 11 meta-analyses of RCTs were included. Cinnamon supplementation was effective in reducing serum FPG (WMD: -10.93 mg/dL; 95%CI: -16.22, -5.65; SMD: -0.86; 95%CI: -1.19, -0.52), insulin (WMD: -2.01 IU/mL; 95%CI: -3.96, -0.07; SMD: -0.61; 95%CI: -0.93, -0.30), HOMA-IR levels (WMD: -0.61; 95%CI: -0.91, -0.31; SMD: -0.78; 95%CI: -1.26, -0.30), and HbA1c (WMD: -0.10%; 95%CI: -0.17, -0.03). CONCLUSION: Cinnamon can be used as an anti-diabetic agent and an add-on treatment to control glycemic indices among patients with T2D or PCOS.

The effect of propolis supplementation in improving antioxidant status: A systematic review and meta-analysis of controlled clinical trials.

The present study aimed to assess the effect of propolis supplementation on oxidative status, a key contributor to the etiology of many chronic diseases. A systematic search of multiple databases, including Web of Science, SCOPUS, Embase, PubMed, and Google Scholar, was conducted from inception to October 2022 to identify articles examining the effect of propolis on glutathione (GSH), glutathione peroxidase (GPX), total antioxidant capacity (TAC), superoxide dismutase (SOD), and malondialdehyde (MDA) levels. The quality of the included studies was evaluated using the Cochrane Collaboration tool. A total of nine studies were included in the final analysis, and a random-effects model was used to pool the estimated effects. Results showed that propolis supplementation significantly increased the levels of GSH (SMD = 3.16; 95% CI: 1.15, 5.18; I2 = 97.2%), GPX (SMD = 0.56; 95% CI: 0.07, 1.05; p = 0.025; I2 = 62.3%), and TAC (SMD = 3.26; 95% CI: 0.89, 5.62; I2 = 97.8%, p < 0.001). However, the effect of propolis on SOD was not significant (SMD = 0.05; 95% CI: -0.25, 0.34; I2 = 0.0%). Although the MDA concentration was not significantly decreased overall (SMD = -0.85, 95% CI: -1.70, 0.09; I2 = 93.3%), a significant decrease in MDA levels was observed at doses ≥1000 mg/day (SMD = -1.90; 95% CI: -2.97, -0.82; I2 = 86.4) and supplementation durations of less than 11 weeks (SMD = -1.56; 95% CI: -2.60, -0.51; I2 = 90.4). These results suggest that propolis is a safe supplement with a beneficial effect on GSH, GPX, and TAC levels and may be an effective adjunctive therapy for diseases where oxidative stress is a key factor in the etiology. However, further high-quality studies are necessary to make more precise and comprehensive recommendations given the limited number of studies, clinical diversity, and other limitations.

The influence of arginine supplementation on IGF-1: A systematic review and meta-analysis.

BACKGROUND: Insulin-like growth factor-1 (IGF-1) secretion is thought to be induced by a semi-essential amino acid called arginine (Arg). Existing research on the effect of Arg on IGF-1 levels has provided conflicting results. This systematic review and meta-analysis investigated the efficacy of acute and chronic Arg supplementation on IGF-1 levels. METHODS: PubMed, Web of Science, and Scopus were systematically searched until November 2022. The meta-analysis was performed using random- and fixed-effects models. Sensitivity and subgroup analyses were also carried out. Publication bias was assessed using Begg's test. RESULTS: Nine studies were included in this meta-analysis. Chronic Arg supplementation did not significantly change IGF-1 levels (SMD = 0.13 ng/ml; %95 CI: -0.21, 0.46; p = 0.457). Furthermore, the IGF-1 level was not significantly affected by acute Arg supplementation (SMD = 0.10 ng/mL; CI: -0.42, 0.62; p = 0.713). The meta-analysis results did not change following subgroup analyses based on the duration, dosage, age, placebo, and study population. CONCLUSION: In conclusion, there was no significant effect of Arg supplementation on IGF-1 concentration. The meta-analyses revealed no acute or chronic Arg supplementation impact on IGF-1 levels.

N-acetylecysteine, a powerful agent in the reinforcement of anti-oxidant profile: A systematic review and dose-response meta-analysis of controlled clinical trials.

BACKGROUND AND AIM: Several studies have been conducted to evaluate the effect of N-acetylecysteine (NAC) supplementation on antioxidant status, while no dose-response meta-analysis summarized the efficacy of NAC supplementation. METHODS: The systematic search of literatures was conducted on Scopus, PubMed, Embase, Web of Science electronic databases. Controlled clinical trials investigating the effects of NAC on antioxidant biomarkers were included in the current meta-analysis. Random-effect model was used to perform meta-analysis. Heterogeneity was examined using I2 index. Subgroup analysis was carried out to find the possible sources of heterogeneity. Dose-response analysis was performed to find the non-linear relationships between effect size and independent variables. RESULTS: Overall, 26 eligible studies were included in the review. NAC supplementation significantly increased TAC (SMD = 0.77 µmol/L; 95% CI: 0.38, 1.16; p < 0.001), GSH (SMD = 0.80 nmol/ml; 95% CI:0.25, 1.34; p = 0.004) and CAT (SMD = -0.57 IU/L; 95% CI:-1.13, -0.02; p = 0.042) levels. However, no significant improving effect was observed in terms of GR (SMD = 0.25 IU/g; 95% CI:-0.14, 0.63; p = 0.210), SOD (SMD = 0.14 U/ml; 95% CI:-0.20, 0.49; p = 0.414) and GPx (SMD = 0.19 IU/g; 95% CI:-0.48, 0.86; p = 0.576) levels. Furthermore, dose-response analysis show that NAC supplementation in participants with mean age up to 30 years had more robust effect on increasing GSH levels. CONCLUSION: We found a significant effect of NAC supplementation on TAC, GSH, CAT in adults. Overall, NAC could be considered as a potent agent in enhancing antioxidant capacity.

Effect of omega-3 supplementation on lipid profile in children and adolescents: a systematic review and meta-analysis of randomized clinical trials.

PURPOSE: Dyslipidemia is considered as a known risk factor for cardiovascular disease. Yet various trials with wide ranges of doses and durations have reported contradictory results. We undertook this meta-analysis of randomized controlled trials (RCTs) to determine whether omega-3 supplementation can affect lipid profile in children and adolescents. METHODS: Cochrane Library, Embase, PubMed, and Scopus databases were searched up to March 2021. Meta-analysis was performed using random-effect method. Effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Heterogeneity was assessed using the I2 index. In order to identification of potential sources of heterogeneity, predefined subgroup and meta-regression analysis was conducted. RESULTS: A total of 14 RCTs with 15 data sets were included. Based on the combination of effect sizes, there was a significant reduction in TG levels (WMD: -15.71 mg/dl, 95% CI: -25.76 to -5.65, P=0.002), with remarkable heterogeneity (I2=88.3%, P<0.001). However, subgroup analysis revealed that omega-3 supplementation significantly decreased TG only in studies conducted on participants ≤13 years old (WMD=-25.09, 95% CI: -43.29 to -6.90, P=0.007), (I2=84.6%, P<0.001) and those with hypertriglyceridemia (WMD=-28.26, 95% CI: -39.12 to -17.41, P<0.001), (I2=0.0%, P=0.934). Omega-3 supplementation had no significant effect on total cholesterol, HDL, and LDL levels. Also, results of nonlinear analysis showed significant effect of treatment duration on HDL status (Pnon-linearity=0.047). CONCLUSION: Omega-3 supplementation may significantly reduce TG levels in younger children and those with hypertriglyceridemia. Also, based on the HDL-related results, clinical trials with longer duration of intervention are recommended in this population.

Effects of probiotics supplementation on blood pressure: An umbrella meta-analysis of randomized controlled trials.

AIMS: Several meta-analyses have revealed that probiotics could lower blood pressure (BP), but the findings were inconsistent. In this regard, an umbrella meta-analysis was carried out to provide a more accurate estimate of the overall impacts of probiotics supplementation on BP. DATA SYNTHESIS: We searched the following international databases till November 2021: PubMed, Scopus, EMBASE, Web of Science, and Google Scholar. A random-effects model was applied to evaluate the effects of probiotics on BP. Sensitivity analysis was performed by using the leave-one-out method. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to evaluate the certainty of evidence. Pooled effect size of 14 meta-analyses with 15,494 participants indicated significant decreases in both systolic (Weighted mean difference (WMD) = -1.96 mmHg; 95% confidence interval (CI): -2.78, -1.14, p < 0.001, and standardized mean difference (SMD) = -2.62; 95% CI: -4.96, -0.28, p < 0.001) and diastolic BP (WMD = -1.28 mmHg; 95% CI: -1.76, -0.79, p < 0.001, and SMD = -0.60 mmHg; 95% CI: -1.08, -0.12, p = 0.014) following probiotics supplementation. Greater effects on SBP were revealed in trials with a mean age of >50 years and the duration of intervention ≤10 weeks. DBP was also more reduced in studies with a dosage of ≥1010 colony forming unit (CFU), and SBP was decreased in patients with hypertension or diabetes analyzing WMD. CONCLUSION: The present umbrella meta-analysis suggests probiotics supplementation to improve BP and claims that probiotics could be used as a complementary therapy for controlling high BP. PROSPERO ID: CRD42022306560.

Probiotics act as a potent intervention in improving lipid profile: An umbrella systematic review and meta-analysis.

Several meta-analysis studies have revealed improving effects of probiotics on lipid profile, while some studies have reported controversial findings. The purpose of present study was to evaluate the efficacy of probiotics on blood lipids. Relevant studies were searched in the international databases, including PubMed, Scopus, EMBASE, Web of Science, and Cochrane Central Library up to August 2021. The pooled results were calculated with the use of a random-effects model to assess the effects of probiotics on blood lipids. Overall, 38 meta-analyses were inclueded in the study. The results indicated that the probiotics supplementation was effective on reduction of total cholesterol (TC) (ES= -0.46 mg/dL; 95% CI: -0.61, -0.30, p < 0.001; I2= 83.8%, p < 0.001), triglycerides (TG) (ES= -0.13 mg/dl; 95% CI: -0.23, -0.04, p = 0.006; I2= 74.7%, p < 0.001), and low-density lipoprotein cholesterol (LDL-C)levels (ES= -0.29 mg/dL; 95% CI: -0.40, -0.19, p < 0.001; I2= 77.8%, p < 0.001). There was no significant effect of probiotics on high-density lipoprotein cholesterol (HDL-C) levels (ES= 0.02 mg/dl; 95% CI: -0.04, 0.08, p = 0.519; I2= 72.5%, p= <0.001). The results of present umbrella meta-analysis strongly support supplementation with probiotics as an influential intervention for improving lipid profile.

Probiotics as an effective therapeutic approach in alleviating depression symptoms: an umbrella meta-analysis.

Growing evidence has suggested that the consumption of probiotics can decrease depressive symptoms. However, even the results of meta-analyses are conflicting. In this regard, we performed an umbrella meta-analysis and proposed the decisive impacts of probiotics on depressive symptoms. The following international databases were searched up to July 2021: PubMed/Medline, Web of Science, Scopus, EMBASE, and Google Scholar. Meta-analyses investigating the impact of supplementation of probiotics on depression symptoms in adults were included. According to the studies, random-effects model was used to perform the analysis. Subgroup analysis was performed by dosage of probiotics, duration of supplementation and total sample size. Publication bias was assessed using Egger's, Begg's and visual inspection of funnel plot. Ten meta-analyses (n = 8886 participants) were included in study. The pooled data indicated that probiotic supplementation significantly reduced depression symptoms (ES= -1.41; 95% CI: -2.53, -0.30, p = 0.016; I2 = 99.4, p = <0.001). Subgroup analysis of studies with intervention duration >8 weeks and dosage >10 × 109 CFU demonstrated a more robust effect of probiotics on decreasing depression symptoms. There was also significant between-study heterogeneity in which dosage was identified as source of it. The results of present umbrella meta-analysis suggest administration of probiotics for relieving depression symptoms for >8 weeks with dosage of >10 × 109 CFU.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2051164.

Can omega-3 fatty acids and vitamin E co-supplementation affect obesity indices?

Background: Studies have shown that vitamin E as an antioxidant protects omega-3 fatty acids (FAs) from oxidation. Several studies have evaluated the effect of omega-3 FAs and vitamin E co-supplementation on obesity indices; however, the results are inconsistent. The present systematic review and meta-analysis was conducted to address the role of omega-3 FAs plus vitamin E on obesity indices. Methods: Cochrane Library, PubMed, Scopus, Embase, and Web of Science databases were searched up to February 2022. Among all of the qualified studies, 10 articles were selected. The effect size was presented as weighted mean difference (WMD) and 95% confidence interval (CI). Fixed-effects model was employed to perform meta-analysis. Subgroup analysis and publication bias assessment were carried out. Results: Ten eligible randomized controlled trials comprising 558 participants were included. The average dose of omega-3 FAs and vitamin E co-supplementation in studies was 1000-4000 mg/day and 400 IU, respectively. Intervention duration varied from 6 to 16 weeks. There was no significant effect of omega-3 and vitamin E co-supplementation on body weight (BW) (WMD=0.14 kg; 95% CI: -0.13 to 0.42; p=0.297), and body mass index (BMI) (WMD=0.08, 95% CI: -0.01 to 0.16, p=0.073). However, subgroup analysis showed that it might increase BMI in women over 50 years and if the intervention lasted more than 8 weeks. Conclusion: There was no significant impact of combined omega-3 FAs and vitamin E supplementation on BW and BMI; however, it should be noted that the intervention has an increasing impact when supplementation duration was >8 weeks and in individuals with type 2 diabetes mellitus, >50 years old, and BMI>25 kg/m2.

Vitamin D protects against depression: Evidence from an umbrella meta-analysis on interventional and observational meta-analyses.

Meta-analyses of interventional and observational studies investigating the efficacy and the relationship between vitamin D and depression provided inconsistent results. The current umbrella meta-analysis was conducted to assess the available evidence and provide a conclusive outcome in this regard. The following international databases were systematically searched till March 2022: PubMed, Scopus, Embase, Web of Science, and Google Scholar. Random-effects model was carried out to calculate the pooled point estimates and their respective 95 % confidence intervals (CI). Ten meta-analyses of randomised controlled trials (RCTs) revealed significant reduction in depression symptoms comparing participants on vitmain D supplements to those on placebo (Pooled standardised mean difference: - 0.40; 95 % CI: - 0.60, - 0.21, p < 0.01: I2 = 89.1 %, p < 0.01). Four meta-analyses of cohort studies (with one having two subgroups) revealed that participants with lower levels of serum vitamin D were at increased odds of depression than those with higher levels of serum vitamin D (Pooled odds ratio: 1.60; 95 % CI: 1.08, 2.36, p < 0.01; I2 = 91.3 %, p < 0.01). The present umbrella meta-analysis confirms the potential benefits of vitamin D supplementation and higher serum vitamin D levels in reducing the development and symptoms of depression.