LAUSR

Diarrhea in livestock species is controlled with antibiotics, but its inadequate use causes bacterial resistance. Lactic acid bacteria (LAB) in the intestinal microbiota have competitive exclusion against pathogens causing diarrhea, and inulin is a substrate for LAB. Therefore, the objective of this study was to determine the prebiotic effect of two inulin sources on in vitro growth of Lactobacillus salivarius (Ls) and Enterococcus faecium (Ef), with the use of Lactobacillus casei (Lc) as a positive control. In vitro incubations were performed at 37 °C, with glucose substitution by inulin of chicory (IAc) or agave (IAg) in MRS medium. The treatments (T) evaluated were T1: MRS-glucose+Lc; T2: MRS-IAc+Ls, T4: MRS-IAc+Ef, T5: MRS-IAg+Lc, T6: MRS-IAg+Ls and T7: MRS-IAg+Ef. The curve and the growth rate were determined by optical density (630 nm) at 0, 3, 6, 12, 24, 30, 36, 48, 54 and 60 h. A completely randomized design was used and the Tukey test for means comparison. MRS-IAg treatments showed higher ( P <0.05) growth rates (0.51 a , 0.50 a and 0.50 a h -1 , T5, T6 and T7, respectively) and were similar to the positive control (T2) when grown in MRS- IAc (0.48 a h -1 ). The positive control (T1) had a low growth rate (0.34 b h -1 ) when the medium included glucose (MRS-glucose). pH during growth was different between treatments ( P <0.05). Agave inulin favors the growth of probiotic bacteria such as Lactobacillus salivarius and Enterococcus faecium , and its prebiotic effect is better than chicory inulin.