Effect of Lactobacillus rhamnosus KY-3 and cellobiose as synbiotics on lipid metabolism in rats.

Lactobacillus rhamnosus KY-3 is a fermentative bacterium that is used for the industrial production of L-lactic acid. We have examined the effect of L. rhamnosus KY-3 and cellobiose as synbiotics on lipid metabolism in rats. Rats were fed on a 20% casein diet (C) supplemented with either 1.7% L. rhamnosus KY-3 (KY-3), 10% cellobiose (CEB), or 1.7% L. rhamnosus KY-3 and 10% cellobiose (KY-3+CEB) for 13 d. The concentrations of serum total lipids, triacylglycerol, total cholesterol, and phospholipids were significantly reduced in rats fed a KY-3+CEB diet in comparison to those on the C, KY-3 and CEB diets. There was an increase in the weight of cecal contents and a significant increase in the amount of cecal short-chain fatty acids (SCFA). The dry weight of excretion increased additively upon the simultaneous administration of L. rhamnosus KY-3 and cellobiose (KY-3 + CEB). The amount of excreted fecal bile acids did not differ among the groups in this study. These findings support the hypothesis that the promotion of cecal fermentation can lower the level of serum lipids. These results suggest that simultaneous administration of L. rhamnosus KY-3 and cellobiose as synbiotics has a beneficial effect on lipid metabolism.