Lilis Nuraida text Malaysian Society for Microbiology 2018 en Vol. 14(3), pp. 282-292 Lilis Nuraida Aims: To evaluate the effectivity of Lactobacillus plantarum BSL isolated from Indonesian sauerkraut against Listeria monocytogenes ATCC 7644 through in vitro and in vivo assay. Methodology and results: In vitro examination for antimicrobial activity against L. monocytogenes ATCC 7644 was performed using seven isolates of lactic acid bacteria (LAB). Lactobacillus plantarum BSL demonstrated the highest activity against L. monocytogenes and studied further in Sprague-Dawley (SD) rats. Treatment group of rats received 0.5 mL culture suspension (109 CFU/mL) of L. plantarum BSL and control group received 0.5 mL of 0.85% w/v NaCl daily during nine days of treatment. Both groups were infected at 3rd day with 0.5 mL of suspension of L. monocytogenes (109CFU/mL). At the 2 nd(before infection), 5 th, 7th, and 9 th day (after infection), the rats were sacrificed and the faeces, caecum, and caecum content were examined for the population of LAB and L. monocytogenes. Administration of L. plantarum BSL significantly increased the population of LAB by 1.2–1.4 log unit, while the number of L. monocytogenes was reduced by 1.8–1.9 log unit compared to control group eithr in the faeces, caecum, or caecum content. Administration of L. plantarum BSL could be able to reduce the liver and spleen damage of the experimental rats, but did not show any changes in immunoglobulin A (IgA) response in comparison with control group. Conclusion, significance and impact of study: Lactobacillus plantarum BSL was promising as probiotic candidate with health promotion to protect the gastrointestinal from infection by L. monocytogenes ATCC 7644. NONE 240212 20240212023944 INLIS000000000015174 Converted from MARCXML to MODS version 3.5 using MARC21slim2MODS3-5.xsl (Revision 1.106 2014/12/19)