Galactomannans are the most effective soluble dietary fibers in type 2 diabetes: a systematic review and network meta-analysis

Anna E Juhász; Dorina Greff; Brigitta Teutsch; Noémi Gede; Péter Hegyi; Eszter M Horváth; Pál Á Deák; Péter Nyirády; Nándor Ács; Réka Juhász

doi:10.1016/j.ajcnut.2022.12.015

Galactomannans are the most effective soluble dietary fibers in type 2 diabetes: a systematic review and network meta-analysis

Am J Clin Nutr. 2023 Feb;117(2):266-277. doi: 10.1016/j.ajcnut.2022.12.015. Epub 2022 Dec 30.

Authors

Affiliations

¹ Center for Translational Medicine, Semmelweis University, Budapest, Hungary; Department of Dietetics and Nutrition Sciences, Semmelweis University, Budapest, Hungary.
² Center for Translational Medicine, Semmelweis University, Budapest, Hungary; Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary; Department of Physiology, Semmelweis University, Budapest, Hungary.
³ Center for Translational Medicine, Semmelweis University, Budapest, Hungary; Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary.
⁴ Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary.
⁵ Center for Translational Medicine, Semmelweis University, Budapest, Hungary; Institute for Translational Medicine, Medical School, University of Pécs, Pécs, Hungary; Institute of Pancreatic Diseases, Semmelweis University, Budapest, Hungary.
⁶ Department of Physiology, Semmelweis University, Budapest, Hungary.
⁷ Department of Interventional Radiology, Heart and Vascular Center, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
⁸ Department of Urology, Semmelweis University, Budapest, Hungary.
⁹ Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary.
¹⁰ Department of Dietetics and Nutrition Sciences, Semmelweis University, Budapest, Hungary. Electronic address: hermanne.juhasz.reka@semmelweis.hu.

PMID: 36811560
DOI: 10.1016/j.ajcnut.2022.12.015

Abstract

Background: Soluble dietary fibers are known to reduce the levels of blood glucose and lipids in patients with type 2 diabetes mellitus (type 2 diabetes). Although several different dietary fiber supplements are utilized, to our knowledge, no previous study has ranked their efficacy yet.

Objectives: We performed this systematic review and network meta-analysis to rank the effects of different types of soluble dietary fibers.

Methods: We performed our last systematic search on November 20, 2022. Eligible randomized controlled trials (RCTs) included adult patients with type 2 diabetes and compared the intake of soluble dietary fibers with that of another type of dietary fiber or no fiber. The outcomes were related to glycemic and lipid levels. The Bayesian method was used to perform a network meta-analysis and calculate the surface under the cumulative ranking (SUCRA) curve values to rank the interventions. The Grading of Recommendations Assessment, Development, and Evaluation system was applied to evaluate the overall quality of the evidence.

Results: We identified 46 RCTs, including data from 2685 patients who received 16 types of dietary fibers as intervention. Galactomannans had the highest effect on reducing the levels of HbA1c (SUCRA: 92.33%) and fasting blood glucose (SUCRA: 85.92%). With regard to fasting insulin level, HOMA-IR, β-glucans (SUCRA: 73.45%), and psyllium (SUCRA: 96.67%) were the most effective interventions. Galactomannans were ranked first in reducing the levels of triglycerides (SUCRA: 82.77%) and LDL cholesterol (SUCRA: 86.56%). With regard to cholesterol and HDL cholesterol levels, xylo-oligosaccharides (SUCRA: 84.59%) and gum arabic (SUCRA: 89.06%) were the most effective fibers. Most comparisons had a low or moderate certainty of evidence.

Conclusions: Galactomannans were the most effective dietary fiber for reducing the levels of HbA1c, fasting blood glucose, triglycerides, and LDL cholesterol in patients with type 2 diabetes. This study was registered at PROSPERO as ID CRD42021282984.

Keywords: dietary fiber; galactomannan; glycemic factors; inulin; lipid levels; ranking; resistant starch; xylo-oligosaccharides; β-glucan.

Publication types

Meta-Analysis
Systematic Review

MeSH terms

Adult
Blood Glucose*
Cholesterol, LDL
Diabetes Mellitus, Type 2*
Dietary Fiber
Glycated Hemoglobin
Humans
Network Meta-Analysis
Triglycerides

Substances

Cholesterol, LDL
Blood Glucose
galactomannan
Glycated Hemoglobin
Triglycerides
Dietary Fiber