The consumption of a bread enriched with dietary fibre and l-carnitine improves glucose homoeostasis and insulin sensitivity in patients with metabolic syndrome

• Insulin resistance is the cornerstone of metabolic syndrome (MetS).
• Role of carnitine and fibre in a bakery product was evaluated in MetS patients.
• Enriched product improved glucose homoeostasis and insulin resistance in MetS.
• This intervention would be an effective first-step strategy for treating hyperglycaemia.

The aim of this study was to evaluate the efficacy of a bakery product enriched with dietary fibre and l-carnitine in countering glucose homoeostasis and insulin sensitivity in patients with and without MetS. This was a 12-week, double-blind, randomized placebo-controlled trial employing fifty-four subjects (28 with MetS and 26 without MetS). After one month (run-in period), subjects were divided into two intervention groups: one received dietary fibre (5.59 g of soluble fibre and 9.49 g of insoluble fibre) plus 2325 mg of l-carnitine enriched bread (n = 26) and the other received placebo bread (n = 28). Anthropometric measurements, biochemical parameters inflammatory markers and LDL subfractions were analysed before and after intervention. Patients with MetS who received the enriched product exhibited a significant decrease in insulin (12.4%), C-peptide (8.9%), HOMA-IR index (14.8%) and in percentage of small and dense LDL. In addition, a significant correlation was found between percentage of change in glucose and baseline glucose levels (r = −0.471; p = 0.017). No changes were detected in either lipid profile or inflammatory markers in patients with or without MetS at any point of the experimental period. In conclusion, dietary fibre plus l-carnitine supplementation improves hydrocarbonated metabolism parameters and insulin resistance, leading to a healthier atherogenic profile in patients with MetS.This trial was registered on clinicaltrial.gov under study number NCT02281253.