Effect of a polyglucosamine on the body weight of male rats: Mechanisms of action

Polyglucosamine (PG) is a low-molecular-weight chitosan (125 kDa) mixed with vitamin C and tartaric acid in standardised proportions. The aim of this study was to determine its effect on the body weight of male rats and clarify the mechanism of action. Three groups of 12 young male rats were fed a standard diet, or a diet containing PG (1% or 2%), for nine weeks. Body weight, food and water intake, and total cholesterol and triglyceride levels were measured before and at the end of treatment; low-density (LDL) and high-density lipoproteins (HDL), the amount of faeces, and their lipid, glucose and acetate content were also measured at the end of treatment.Total body weight increased by 234 ± 44.2 g in the controls, 233 ± 32.4 g in the rats fed PG 1%, and 206 ± 32.8 in those fed PG 2%; the weight increase was significantly less only in the PG 2% group, with the greatest difference being reached after four weeks (p < 0.01). Food intake was similar in all three groups. Twenty-four hour faecal weight/body weight was significantly higher (p < 0.05) in the animals treated with PG 2% than in the controls; faecal lipid, acetate, glucose and water content were also significantly higher in the PG 2% group. There was no significant change in the plasma lipid profiles of any of the groups.Dietary PG 2% reduces body weight, increases faecal weight (and faecal lipid and water content), and makes available fats and glucose as fuel for colon bacteria, as indicated by the higher acetate content.