Acetogenic fibers reduce fasting glucose turnover but not peripheral insulin resistance in metabolic syndrome patients.
BACKGROUND & AIMS
The acute ingestion of an acetogenic indigestible carbohydrate (lactulose) increased acetate turnover associated with decreased lipolysis (glycerol turnover) in insulin-resistant patients. It is not known whether a decreased lipolysis by chronic ingestion of acetogenic indigestible carbohydrates or fibers improves glucose turnover and insulin sensitivity.


METHODS
Twenty-one men with metabolic syndrome ingested daily standardized drinks, with or without 28 g acetogenic fibers (acacia gum and pectin), for 5 weeks in a randomized double-blind crossover controlled study design. Euglycaemic-hyperinsulinaemic (EH) clamps coupled with kinetic studies were performed in the fasting state after treatments.


RESULTS
Flatulence was more frequent with fiber treatment. Body weight, lipids as well as acetate and glycerol turnovers were unchanged. Fasting endogenous glucose turnover was improved after fiber treatment (7.9 ± 1.3 μmol kg(-1) min(-1)) compared with control (8.6 ± 1.6 μmol kg(-1) min(-1), P < 0.05). But insulin sensitivity (glucose infusion rate) during the EH clamp was not different at the end of fiber and control treatments, 3.7 ± 1.8 and 3.8 ± 1.5 mg kg(-1) min(-1), respectively, nor fasting plasma glucose and insulin.


CONCLUSIONS
The chronic ingestion of acacia gum and pectin fibers did not decrease lipolysis but improved fasting endogenous glucose turnover with no effect on peripheral insulin resistance in metabolic syndrome patients.