The effects of guar gum supplementation on lipid profile in adults: A GRADE-assessed systematic review, meta-regression, and dose-response meta-analysis of randomized placebo-controlled trials

Abstract

Recent meta-analytic work indicated that guar gum supplementation might improve lipid profile markers in different populations. However, critical methodological limitations such as the use of some unreliable data and the lack of inclusion of several relevant studies, and the scarcity in assessments of regression and dose-specific effects make it difficult to draw meaningful conclusions from the meta-analysis. Therefore, current evidence regarding the effects of guar gum supplementation on lipid profile remains unclear. The present systematic review, meta-regression, and dose-response meta-analysis aimed to examine the effects of guar gum supplementation on lipid profile (total cholesterol TC, low-density lipoprotein LDL, triglyceride TG, and high-density lipoprotein HDL) in adults. Relevant studies were obtained by searching the PubMed, SCOPUS, Embase, and Web of Science databases (from inception to September 2021). Weighted mean differences (WMD) and 95% confidence intervals (95% CI) were estimated via a random-effects model. Heterogeneity, sensitivity analysis, and publication bias were reported using standard methods. Pooled analysis of 19 randomized controlled trials (RCTs) revealed that guar gum supplementation led to significant reductions in TC (WMD: -19.34 mg/dL, 95% CI: -26.18, -12.49, p<0.001) and LDL (WMD: -16.19 mg/dL, 95% CI: -25.54, -6.83, p=0.001). However, there was no effect on TG and HDL among adults in comparison with control group. Our outcomes suggest that guar gum supplementation lowers TC and LDL in adults. Future large RCTs on various populations are needed to show further beneficial effects of guar gum supplementation on lipid profile and establish guidelines for clinical practice.