It is generally accepted that the micro-flora resident in the intestinal tract has a major impact on gastrointestinal function and thereby on the health of the host. Probiotics are defined as "live microbial feed supplements, which beneficially effect the host animal by improving its intestinal microbial balance". Today, the majority of probiotic products are designed for human or cattle application. However, it is reasonable to assume that similar positive effects can be received by using probiotics in pets. To investigate potential health beneficial effects of probiotics in pets over 50 different strains of lactic acid bacteria were isolated from cats and dogs, identified and characterized for relevant technological and physiological properties. Based on this first evaluation six strains were selected and their potential to inhibit the growth of pet enteropathogens was investigated in co-cultivation experiments in an in vitro model simulating small intestinal conditions. It could be demonstrated that two out of the six isolates were able to inhibit and inactivate pathogenic bacteria such as enterotoxinogenic strains of E. coli, Salmonella typhimurium and Shigella dysenteriae.

One potential probiotic strain, showing promising results in vitro was used for an in vivo study with gnotobiotic mice. In this study the anti-pathogenic effects against Salmonella typhi and the immune-modulating effects of this particular strain were investigated. Further in vivo studies investigating the probiotic potential of this bacterial strain are on the way.