Consumption of galactosyl derivatives of polyols beneficially affects cecal fermentation and serum parameters in rats

We compared the effects of polyols (lactitol, xylitol) and new products of β-galactosyl derivatives of polyols (gal-xylitol, gal-sorbitol) on cecal fermentation and biochemical indicators of serum in rats adapted for 2 weeks to a semipurified diet. All investigated preparations were added to replace the sucrose component of the control diet (5% of dry matter). The presence of polyols and β-galactosyl derivatives of polyols in the diet caused cecal enlargement (especially lactitol and gal-sorbitol; 105% and 94% vs control, control, respectively), lowered cecal pH (especially gal-sorbitol, 15% vs control) and activity of β-glucuronidase (to a lesser extent in the case of xylitol), as well as enhanced protein (48%-103% vs control) and short-chain fatty acid production in the digesta (68%-107% vs control). Except for xylitol, all preparations (especially gal-sorbitol) lowered ammonia concentration in the cecum (27% vs control). Compared with xylitol, β-galactosyl xylitol was more effective in lowering cecal pH (6.62 and 6.44, respectively) and increasing protein concentration and protein pool in the cecum. Lactitol and gal-sorbitol were characterized by higher butyrate (5.99 and 6.03 μmol/g, respectively, vs 3.65 in control), whereas xylitol and gal-xylitol were characterized by higher propionate concentration (22.94 and 22.19 μmol/g, respectively, vs 10.36 in control) and content in the digesta. All preparations, especially lactitol and gal-sorbitol, lowered glucose concentration in the serum. The reduction in cholesterol content was observed only in the case of xylitol and gal-xylitol (12%-17% vs control). Galactosyl derivatives of polyol can promote beneficial cecal fermentation in rats and would be potential sources of functional food additives.