Survey of Pathogen-Lowering and Immuno-Modulatory Effects Upon Treatment of Campylobacter coli-Infected Secondary Abiotic IL-10(−/−) Mice with the Probiotic Formulation Aviguard(®)

The prevalence of infections with the zoonotic enteritis pathogen Campylobacter coli is increasing. Probiotic formulations constitute promising antibiotic-independent approaches to reduce intestinal pathogen loads and modulate pathogen-induced immune responses in the infected human host, resulting in acute campylobacteriosis and post-infectious sequelae. Here, we address potential antipathogenic and immuno-modulatory effects of the commercial product Aviguard(®) during experimental campylobacteriosis. Secondary abiotic IL-10(−/−) mice were infected with a C. coli patient isolate on days 0 and 1, followed by oral Aviguard(®) treatment on days 2, 3 and 4. Until day 6 post-infection, Aviguard(®) treatment could lower the pathogen burdens within the proximal but not the distal intestinal tract. In contrast, the probiotic bacteria had sufficiently established in the intestines with lower fecal loads of obligate anaerobic species in C. coli-infected as compared to uninfected mice following Aviguard(®) treatment. Aviguard(®) application did not result in alleviated clinical signs, histopathological or apoptotic changes in the colon of infected IL-10(−/−) mice, whereas, however, Aviguard(®) treatment could dampen pathogen-induced innate and adaptive immune responses in the colon, accompanied by less distinct intestinal proinflammatory cytokine secretion. In conclusion, Aviguard(®) constitutes a promising probiotic compound to alleviate enteropathogen-induced proinflammatory immune responses during human campylobacteriosis.