The objective of the current work was to evaluate the use of oral probiotics comprised of viable and inactivated Lactobacillus spp. (referred to herein as "pool" of Lactobacillus spp.) on the performance, intestinal microbiota and blood parameters of piglets from birth to 35 days of age. Lactation piglets (n=108), with an average initial weight of 1.41kg, and nursery piglets (n=72), with an average initial weight of 5.47kg, were included in the study and distributed in a randomized complete block design. The treatments were as follows: Control: 1mL MRS broth + 1mL sterile saline; Active: 1 mL probiotics ("pool" of Lactobacillus spp. and Lactobacillus plantarum) activated in MRS broth + 1 ml saline; Inactive: 1 mL inactivated probiotics containing MRS broth + 1mL saline. Treatments were not observed to affect total and daily weight gain of piglets during lactation. Differences were observed between treatments for feed intake, daily feed intake as well as total and daily weight gain from 21 to 35 days of age. Counts of lactic acid bacteria and coliforms were not affected by treatment or age. With the exception of globulin, blood parameters are also not affected. In the nursery phase the probiotic treatment with inactivated cells means a viable alternative for use primarily by the performance obtained for weight gain; however probiotics supplementation did not influence the microbiological counts and blood parameters.