TDK conference 2018

Since the 1960’s, wide spread use of sub-therapeutic levels of feed antibiotics for monogastric animals has been practiced. This has led to serious issues with antibiotic resistance and subsequently in 2006 the use of antibiotics as growth promotors were banned in the European Union. In the case of food producing animals, for example pigs, intestinal disease results in significant economic loss. Therefore, it is an important research issue to find substitute natural ingredients that can maintain the health of the gut. The use of probiotics offers an alternative to enhance gastrointestinal health.

One of the most important ways in which probiotics exert their beneficial effect on their host, is by modifying metabolic processes. Probiotics have also been found to strengthen the intestinal barrier against noxious stimuli. However, some of the underlying mechanisms are still undiscovered.

In this work the in vitro effect of three probiotic bacterial strains (Enterococcus faecium, Lactobacillus rhamnosus, Lactobacillus plantarum) will be investigated. The cell line featured in this study is IPEC-J2, isolated from the jejunum of a neonatal unsuckled piglet. Our main research question is on the one hand to determine the appropriate treatment conditions (probiotic bacterial supernatant concentration and applied treatment time) and on the other hand to examine the effect of probiotic treatment on the structure and function of enterocytes.

IPEC-J2 cells were treated with spent culture supernatants (SCS) derived from the probiotic strains using different incubation times and concentrations. Afterwards, viability measurement was carried out using the Neutral Red method. Structural and functional studies on enterocytes were carried out with electron microscopy and immunohistochemistry. Size of enterocytes, vacuoles, number of microvilli and presence of tight junction proteins were studied as well.

We found that all three bacterial strains exerted a significant beneficial effect on the cell viability of IPEC-J2 cells, although alterations in the extent could be observed. Our investigations with electron microscopy and immunohistochemistry confirmed that the treatment with probiotics had an effect on the structure and function of IPEC-J2 cells.

The project is supported by the European Union and co-financed by the European Social Fund (EFOP 3.6.1-16- 2016-00024). It was also supported by University of Veterinary Medicine Doctoral School and by NKB Research Grant.