Effects of prebiotic carbohydrates on the growth promotion and cholesterol-lowering abilities of compound probiotics in vitro

Abstract The objective of this study was to evaluate the effects of carbohydrates on the growth and cholesterol-lowering abilities of compound probiotics. The tolerance in simulated gastrointestinal fluids and the antagonism of probiotics were evaluated. Except for Streptococcus thermophilus ldbm1, the probiotics showed good tolerance to simulated gastric juice, and the survival rates were 83.24%, 82.97% and 80.24% after 3 h, respectively. The tolerance of S. thermophilus gld2 to simulated intestinal fluid was significantly higher than that of the other strains, and the survival rate was 71.88% after 24 h. Antagonism was not observed between the strains, except for L. peracasei S0940 with S. thermophilus gld1 and S. thermophilus gld2. The results indicate that galactooligosaccharide had the highest effect on growth and cholesterol-lowering ability when S. thermophilus gld1 and S. thermophilus gld2 were compounded at a ratio of 1:2, the OD600 values reached 1.203 and the cholesterol removal rate reached 50%,followed by stachyose, the cholesterol removal rate was 47.19%. The addition of inulin had a poor impact on the compound probiotics, resulting in the low OD600 values (0.755) and cholesterol removal rate (22.71%). Therefore, the combination of different carbohydrates and compound probiotics provides a basis for the development of functional products.