Effects of soluble dietary fiber on glycolipid metabolism in gestational diabetes mellitus: study protocol for a clinical trial

Background: Accumulating evidence suggests that additional dietary fiber supplements may significantly improve glycolipid metabolism and pregnancy outcomes in individuals with gestational diabetes mellitus (GDM). However, the therapeutic effects of xylose oligosaccharides and inulin (XOS inulin) have not been investigated. Moreover, the underlying mechanism behind the therapeutic effects of this type of dietary fiber is not clear. Our study aims to assess the effects of daily XOS inulin supplementation on glycolipid metabolism and elucidated the therapeutic mechanism through intestinal microbiota analysis. Methods: This study is an 8-week, parallel-design, open-label, 3-arm, single-center randomized controlled trial. Eligible participants were pregnant women between 24 and 28 weeks of gestation, and they were diagnosed with GDM through an oral glucose tolerance test (OGTT). The participants in the three groups will receive nutrition education, nutrition education plus XOS inulin (XOS 2 grams and inulin 10 grams) 12 grams/d, or nutrition education plus XOS inulin 24 grams/d. Measurements will be taken at baseline, week four and week eight. The primary outcome is the change in glycosylated serum protein (GSP), and the key secondary outcomes include changes in fasting glucose, fasting insulin (FINS), 2 h postprandial plasma glucose(2 h-PPG), HbA1c, total cholesterol (TC), triglycerides (TG), LDL cholesterol (LDL-C), HDL cholesterol (HDL-C) and changes in the gut microbiota. Discussion: This study will provide evidence for the benefits of XOS inulin supplementation in GDM patients. This study also provides insight into the potential role of the gut microbiome as a target for enhancing the therapeutic efficacy of emerging treatments for GDM. Trail registration: This trial was registered in the Chinese Clinical Trial registry: ChiCTR2200060117. Registration date: 19, May, 2022.April 2023