Effect of Lactobacillus casei subsp. casei R-68 Isolated from Dadih on the Procarcinogenic Enzyme Activity and Fecal Microflora Count of Rats Challenged with Pathogenic Bacteria

The human digestive tract is a complex ecosystem that may contain bacteria, yeast, and other microflora, which have harmful and beneficial effects on the host. Species of Lactobacillus and Bifidobacterium are most commonly used as probiotics. Lactobacillus casei subsp. casei R-68 (LCR-68) isolated from dadih, traditional fermented buffalo milk from West Sumatera has the potential to be used as probiotic. The purposes of the present study were to evaluate the ability of strain LCR68 to inhibit the growth of the pathogenic bacteria Listeria monocytogenes FNCC-0156 and Escherichia coli FNCC-19 and reduce the activity of fecal mutagen enzymes in Wistar rats. The in vivo test used 25 male Wistar rats with an average weight of 174 - 176 g. This study consisted of five groups of treatment with five rats of each group. The results show a significant increase in the growth in all groups, although a significantly lower weight gain was observed in rats challenged with Listeria monocytogenes and fed fermented milk LCR-68. The counts of aerobic and anaerobic microbes were the same in all groups. Significantly higher counts of lactic acid bacteria were determined after the application of fermented milk LCR68. Significantly lower counts of Escherichia coli were also observed after the application of fermented milk LCR68. The presence of LCR-68 in fermented milk reduced the activity of β-glucuronidase and β-glucosidase significantly in the feces of Wistar rats. Therefore, the strain R-68 as a probiotic is expected to be able to prevent the formation of procarcinogenic compounds into carcinogens that cause cancer in the digestive tract.