The effects of butyrate supplementation on glycemic control, lipid profile, blood pressure, nitric oxide level and glutathione peroxidase activity in type 2 diabetic patients: A randomized triple -blind, placebo-controlled trial

Background: This study aimed to investigate the effects of oral NaBut on metabolic parameters, blood pressure, and oxidative stress indices including glutathione peroxidase (GPx) and nitric oxide (NO) status in type 2 diabetic patients. Methods: In the current interventional trial, 42 patients with type 2 diabetes mellitus (T2DM) were randomly allocated into either NaBut (n = 21) or placebo (n = 21) group for six weeks. Serum concentrations of metabolic parameters, GPx, NO as well as blood pressure were assessed before and after the intervention. Results: Within-group findings demonstrated that NaBut administration significantly reduced systolic and diastolic blood pressure (p = 0.016 and p = 0.002, respectively). Blood sugar 2-hr postprandial (BS2hpp) was also significantly decreased in the intervention and placebo groups (p = 0.016 and p = 0.019, respectively), but the between-group differences were not statistically significant. Differences in homeostatic model assessment of insulin resistance (HOMA-IR) were not significant between groups after adjustment for potential confounders (p = 0.061). NaBut supplementation was also found to significantly increase total cholesterol (p = 0.001), low-density lipoprotein cholesterol (p = 0.005), and insulin levels (p = 0.047) compared to the baseline, while decreased NO levels (p = 0.040). However, there were no significant between-group differences in these parameters. No significant differences were also found in other parameters. Conclusions: We observed significant within-group decreases in systolic and diastolic blood pressure as well as BS2hpp following oral butyrate treatment. While no or even adverse changes in other biochemical parameters were found. Further investigations with longer durations are warranted to more vividly elucidate the effects of NaBut supplementation on patients with T2DM. Registered under Iranian Registry of Clinical Trials website (http://www.irct.ir), Identifier no. IRC T20090609002017N33.