Combined Use of C. butyricum Sx-01 and L. salivarius C-1-3 Improves Intestinal Health and Reduces the Amount of Lipids in Serum via Modulation of Gut Microbiota in Mice

The study was conducted to investigate whether combined use of C. butyricum Sx-01 and L. salivarius C-1-3 could improve the intestinal health and reduce the lipid levels in sera of mice and whether these benefits were related to regulating the intestinal microflora. Eighty Kunming male mice were divided into four groups with five replicates per group and four mice per replicate. Mice in the control group were administrated with 0.2 mL normal saline; mice in three experimental groups were daily orally administrated with 4 × 10(8) cfu of L. salivarius, 4 × 10(8) cfu of C. butyricum, and a combination thereof (2 × 10(8) cfu of L. salivarius, and 2 × 10(8) cfu of C. butyricum), respectively. The experiment lasted for 14 days. The results showed that the average daily feed intake (ADFI) and feed/gain (F/G) ratio of growing mice underwent no significant changes (p > 0.05); however, the average daily gain (ADG) tended to increase over short periods of time. The activities of SOD and GSH-Px in serum in the combination group were significantly increased (p < 0.05); The triglyceride, and total cholesterol, contents in serum in the combined treatment group were significantly decreased (p < 0.05); The total volatile fatty acids and butyric acid in faecal matter of mice in the experimental groups were all significantly increased at 14 days (p < 0.05); The length of villi, and the mucosal thickness of colon and caecum (p < 0.05) were significantly improved; The relative abundance of some bacteria with antioxidant capacity or decomposing cholesterol capacity or butyrate producing capacity was increased, while the relative abundance of some pathogenic bacteria was decreased in the colon. Furthermore, our results showed that the beneficial effects of the combined use of the two strains was higher than that of single use. Overall, the results demonstrated that the combined use of C. butyricum Sx-01 and L. salivarius C-1-3 can significantly improve intestinal health and reduce the amount of lipids in sera of mice. The reason for these effects might be that besides their own probiotic effects, combined use of the two strains could regulate the intestinal microflora.