Probiotics are live microbial food supplements that can be considered a functional food. They benefit the health of a host animal by maintaining their intestinal microbial balance. Most probiotic microorganisms are lactic acid bacteria (LAB) such as Lactobacillus spp., Bifidobacterium spp., and Enterococcus spp. LAB have been reported to possess certain anticancer properties. | Turkish Journal of Biology Turk J Biol (2015) 39: 23-30 © TÜBİTAK doi: Research Article Cytotoxic effects of various lactic acid bacteria on Caco-2 cells 1, 1 2 2 Sevda ER *, Ayşe Tansu KOPARAL , Merih KIVANÇ Department of Microbiology, School of Pharmacy, İstanbul Medipol University, İstanbul, Turkey 2 Department of Biology, Faculty of Sciences, Anadolu University, Eskişehir, Turkey Received: Accepted: Published Online: Printed: Abstract: Probiotics are live microbial food supplements that can be considered a functional food. They benefit the health of a host animal by maintaining their intestinal microbial balance. Most probiotic microorganisms are lactic acid bacteria (LAB) such as Lactobacillus spp., Bifidobacterium spp., and Enterococcus spp. LAB have been reported to possess certain anticancer properties. The vast majority of studies on their anticancer effects have dealt with colorectal cancers, although there have also been some studies on breast and bladder cancers. Colon cancer is the fourth most common cause of cancer-related mortality in the world. The aim of this study was to investigate the antiproliferative effects of the cell-free filtrate and the cell-free lyophilized filtrate of 3 LAB (Pediococcus pentosaceus, Lactobacillus plantarum, and Weissella confusa) on human colorectal adenocarcinoma cell line Caco-2. The filtrates were found to inhibit the growth of colon cancer cells in a dose-dependent manner as detected by the MTT (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, suggesting that these strains might have use as probiotics in functional food or for colon cancer treatment. There are no other studies related to the anticancer activities of W. confusa in the literature. Key words: Probiotics, lactic acid bacteria, cell-free filtrate, Caco-2, MTT assay 1. Introduction Probiotics are live microbial food .
