RESUMO
PURPOSE: The objective was to evaluate the antagonistic effect of Lactobacillus and Bifidobacterium recovered from five commercial probiotics on the growth of C. albicans. STUDY DESIGN: The Lactobacillus and Bifidobacterium strains of five commercial probiotics were recovered and grown: Probio Hp+®, ProBiseis®, Lactipan®, Liolactil®, and Lacteol Fort®; 50 mg of each was hydrated and grown in Lactobacilli MRS (De Man, Rogosa and Sharpe) broth and incubated at 37°C with stirring (120 RPM) for 24 hours. Serial dilutions of 10-1 to 10-7 were made and viability was verified and quantified. For the antagonism tests, a suspension/inoculum of Lactobacillus strains recovered from each commercial preparation (4-30 × 109) and C. albicans ATCC 90028 (1.5-8 × 108) was prepared in MRS broth and incubated for 48 hours at 36°C, then plated on Dextrose Sabouraud Agar with Chloramphenicol and Rogosa Agar and the colony-forming units (CFU) were quantified. Additionally, viability was evaluated using the LIVE/DEAD® Yeast and Bacterial Viability kit. RESULTS: The probiotic that produced the highest acidity of the medium was Lactipan®, followed by Probiseis® and Liolactil®, while Probio Hp+® showed the least change. Probiseis® was determined to have the highest growth of probiotic bacteria and the highest inhibition on C. albicans, followed by Lactipan®; Liolactil® and ProbioHp+® showed the least effect. In fluorescence tests, ProBiseis® showed the best effect, followed by Liolactil® and Lactipan®; Probio Hp+® had less of an effect. CONCLUSIONS: Two commercial products (ProBiseis and Lactipan) whose formulations have L. acidophilus, L. casei, L. rhamnosus, L. plantarum, B. infantis, and S. thermophilus have a greater inhibitory effect on C. albicans ATCC 90028.