Work package 2 (WP2)

WP2: Antimicrobial and gut cellular mechanisms of COL

Background: Anti-microbial and immune-modulatory activity along the gut barrier may partly explain the important biological activity of COL due to its bioactive components. This needs to be documented for the optimized COL product(s) and compared with a COL product (from the same original COL source), subjected to conventional processing conditions (e.g. more damage by pasteurization, drying, filtration).

Methods: Two COL products obtained from WP1 together with two fractions from each product (fat and skimmed fractions) will be tested for direct antimicrobial activity and small intestinal cellular mechanisms.

In WP2.1,  COL fractions will be incubated with various pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli) at different doses, followed by quantification of viability of pathogens to determine antimicrobial activity. WP2.1 will be performed in collaboration with AUS partner.

In WP2.2, selected COL fractions are tested for their proliferative, anti-apoptotic and immuno-modulatory effects in vitro using a selected cell line obtained from porcine or human isolated intestinal epithelial cells. Similar to WP1, a raw COL and a freeze-dried COL from the same batch may be added as additional positive controls in WP2.1 and 2.2.

Both assay systems will identify the potential origin for bioactivity of COL, either from protein or fat fractions or a whole product matrix, needed for documentation of COL effects. The tests also function as screening tools to control and substantiate the optimal processing for COL products in WP1.

Expected results: We expect to document higher levels of antimicrobial activities against pathogens and greater immune-modulatory effects in intestinal cells in vitro of the current optimized COL product, relative to the product produced by conventional processing conditions. Results from WP2 are expected to correlate well with the levels of bioactive components in COL products, as analyzed in WP1.