TDK conference 2018

While rising up piglets, it is important to keep their alimentary tract healthy, and using probiotic bacterial cultures in adequate amounts can contribute to prevent proneness to diseases. In order to avoid unnecessary experimenting on live animals, another alternative is to conduct the research in in vitro conditions, for example using cell cultures. In our study we have used two kinds of probiotic bacteria: Lactobacillus rhamnosus, and Enterococcus faecium. Several probiotic products contain them, because of their positive impact on the digestive system. Lactobacillus rhamnosus is primarly used for fermenting dairy products. Enterococcus faecium has a great tolerance of high salt concentrations, thanks to that it is often used for food conservation and it also produces bacteriocines which prevent the growth of pathogenic microorganisms.

The goal of our research is to define the role of these probiotic bacteria in intestinal epithelium inflammations caused by pathogenic microorganisms.

To conduct our study we used live cell cultures (IPEC-J2 cell line), orginating from the jejunum of newborn piglets. During the experiment we tested the viability of the cells by neutral-red uptake assay (NRU), and the resistance of the cell membranes by measuring transepithelial electric resistance (TER). To induce the inflammation of the tissue, we used bacterial lipopolysaccharide solution (LPS), in 10 ug/ml concentrations. We added the filtrate of the 24 hour old probiotic bacterial cultures to the intestinal epithelium cell lines in concentrations from 1% to 10%. The production of interleukin-6 by the intestinal cells was checked using ELISA tests.

The TER values have decreased one hour after the treatment, however after 24 hours we have measured higher TER values than before the treatment. This suggests that the resistance of the cells had not decreased while using the probiotic bacteria, thus their viability did not decrease either. The results showed that both Enterococcus faecium and Lactobacillus rhamnosus used in appropriate concentrations prevented the rising of interleukin-6 levels, when used along with LPS treatment.

Although several positive effects of probiotics are already known, in order to get a clear sight on their role in inflammatory processes it is necessary to conduct further measurements on other cell types, and also to examine more inflammatory mediators.