1a.Objectives (from AD-416)
1. To evaluate effects of Lactobacillus acidophilus NP51 on host immune response.
2. To evaluate effects of NP51 on the prevention of MAP infection.
3. To evaluate effects of NP51 on the treatment of MAP infection.
1b.Approach (from AD-416)
Mice will be fed NP51 before and after challenge with MAP to ascertain the effectiveness in prevention or treatment of the infection and colonization of target tissues such as spleen, ileum, and mesenteric lymph nodes. The host response to NP51 will be determined by evaluation of cytokine induction alone and in tandem with MAP infection.
This collaborative research project between ARS National Animal Disease Center (NADC) and the Department of Animal Science, Iowa State University, encompasses measures to ensure animal health through the control and management of the disease by improving knowledge of host immunity during infection. Feeding the probiotic, NP51, will allow us to determine if altering the gut ecology of the host will prevent colonization of Mycobacterium avium subspecies paratuberculosis (MAP) in the small intestine and associated tissues. As part of the study, we will attempt to determine if the mechanism of action of the probiotic is correlated with altered host immunity, both in the peripheral blood and at the site of infection. Gaining a further understanding into the host immune responses to MAP infection will add insight into the pathogenesis of this bacterium, providing us with information that will be helpful in potential treatments for infection in dairy cattle. At the present time, one mouse study has been completed to evaluate the effects of feeding different levels of the probiotic on host immune responses and pathology of tissues. Feeding the highest level of probiotic did not affect the health of the mice. Data analyses are underway to determine effects of the probiotic on cell populations and immune cell function. A second study was completed in which the probiotic was fed to mice prior to challenge with live MAP. Data analyses are currently underway for this experiment as well. These data will be useful in determining if probiotics can be used for the treatment and prevention of paratuberculosis in cattle. Progress will be monitored by associated parties via monthly phone calls and/or e-mails and meetings every 2-3 months.