Effect of Beta-Alanine Supplementation on Maximal Intensity Exercise in Trained Young Male Individuals: A Systematic Review and Meta-Analysis.

Beta-alanine is a nonessential amino acid that is commonly used to improve exercise performance. It could influence the buffering of hydrogen ions produced during intense exercise and delay fatigue, providing a substrate for increased synthesis of intramuscular carnosine. This systematic review evaluates the effects of beta-alanine supplementation on maximal intensity exercise in trained, young, male individuals. Six databases were searched on August 10, 2023, to identify randomized, double-blinded, placebo-controlled trials investigating the effect of chronic beta-alanine supplementation in trained male individuals with an age range of 18-40 years. Studies evaluating exercise performance through maximal or supramaximal intensity efforts falling within the 0.5-10 min duration were included. A total of 18 individual studies were analyzed, employing 18 exercise test protocols and 15 outcome measures in 331 participants. A significant (p = .01) result was observed with an overall effect size of 0.39 (95% confidence interval [CI] [0.09, 0.69]), in favor of beta-alanine supplementation versus placebo. Results indicate significant effects at 4 weeks of supplementation, effect size 0.34 (95% CI [0.02, 0.67], p = .04); 4-10 min of maximal effort, effect size 0.55 (95% CI [0.07, 1.04], p = .03); and a high beta-alanine dosage of 5.6-6.4 g per day, effect size 0.35 (95% CI [0.09, 0.62], p = .009). The results provide insights into which exercise modality will benefit the most, and which dosage protocols and durations stand to provide the greatest ergogenic effects. This may be used to inform further research, and professional or recreational training design, and optimization of supplementation strategies.

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 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 Sciences 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 a significant effect on 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.

Effects of Vaccinium berries (blueberries, cranberries and bilberries) on oxidative stress, inflammation, exercise performance, and recovery - a systematic review.

Exercise-induced muscle damage is common in athletes and recreational exercisers and can lead to muscle soreness, weakness, and impaired muscle function. The precise mechanisms are unclear but oxidative stress and inflammation are thought to play a role. (Poly)phenols are substances abundant in Vaccinium berries that have been suggested to possess antioxidant and anti-inflammatory effects that could help improve exercise performance and/or recovery from exercise. The objective of this systematic review was to evaluate the benefits of Vaccinium berry supplementation on exercise performance and recovery, as well as on exercise-induced oxidative and inflammatory biomarkers in healthy individuals. A comprehensive search was conducted in PubMed, ProQuest Medline, Web of Science, Cochrane Library, and Scopus. Studies were included if the participants were healthy individuals who were supplemented with any Vaccinium berry or Vaccinium berry-based products in comparison to a control group. Of the 13 articles included in this review, no significant differences in the exercise performance were found and only one study reported benefits for markers of recovery. Interleukins and c-reactive protein were the most frequently reported biomarkers, but there was limited evidence that Vaccinium berry supplementation impacted them post-exercise. Most studies were of high quality and showed a low risk of bias. Vaccinium berry supplementation is not effective in modulating markers of exercise-induced inflammation and oxidative distress in healthy individuals; nevertheless, more studies are required to evaluate their effects on exercise performance and recovery in this population.