Hargis, B. | Search bioRxiv

bioRxiv2019

Microbial metabolite deoxycholic acid shapes microbiota against Campylobacter jejuni chicken colonization

Despite reducing the prevalent foodborne pathogen Campylobacter jejuni in chickens decreases campylobacteriosis, few effective approaches are available. The aim of this study was to use microbial metabolic product bile acids to reduce C. jejuni chicken colonization. Broiler chicks were fed with deoxycholic acid (DCA), lithocholic acid (LCA), or ursodeoxycholic acid (UDCA). The birds were also transplanted with DCA modulated anaerobes (DCA-Anaero) or aerobes (DCA-Aero). The birds were infected with human clinical isolate C. jejuni 81-176 or chicken isolate C. jejuni AR101. Notably, C. jejuni 81-176 was readily colonized intestinal tract at d16 and reached an almost plateau at d21. Remarkably, DCA excluded C. jejuni cecal colonization at 100, 99.997, and 100% at 16, 21, and 28 days of age. Neither chicken ages of infection nor LCA or UDCA altered C. jejuni AR101 chicken colonization level, while DCA reduced 91% of the bacterium in chickens at d28. Notably, DCA diet reduced phylum Firmicutes but increased Bacteroidetes compared to infected control birds. Importantly, DCA-Anaero attenuated 93% of C. jejuni colonization at d28 compared to control infected birds. In conclusion, DCA shapes microbiota composition against C. jejuni colonization in chickens, suggesting a bidirectional interaction between microbiota and microbial metabolites.

microbiology↗

bioRxiv2018

Microbiota metabolic product deoxycholic acid controls chicken necrotic enteritis

Necrotic enteritis (NE) caused by Clostridium perfringens infection has reemerged as a prevalent poultry disease worldwide due to reduced usage of prophylactic antibiotics. The lack of alternative antimicrobial strategies to control this disease is mainly due to limited insight into NE pathogenesis, microbiome relationships, and host responses. Here we reported that the metabolic byproduct of microbial metabolism of bile acids to deoxycholic acid (DCA), at as low as 50 M, inhibited 82.8% of C. perfringens growth in Tryptic Soy Broth (P < 0.05). Sequential Eimeria maxima and C. perfringens challenge strongly induced NE, severe intestinal inflammation, and body weight (BW) loss in broiler chickens. These negative effects were diminished by 1.5 g/kg DCA diet. At the cellular level, DCA alleviated NE-associated ileal epithelial death and lamina propria immune cell apoptosis. Interestingly, DCA reduced C. perfringens invasion into villi without significantly altering the bacterial luminal colonization. Molecular analysis showed that DCA reduced inflammatory mediators of Inf{gamma}, Litaf (Tnf), Il1{beta}, and Mmp9 mRNA accumulation in ileal tissue. Mechanically, C. perfringens induced elevated expression of inflammatory cytokines of Inf{gamma}, Litaf, and Ptgs2 (COX-2 gene) in chicken splenocytes. Inhibiting the COX signaling by aspirin attenuated INF{gamma}- or TNFa-induced inflammatory response in the splenocytes. Consistently, chickens fed 0.12 g/kg aspirin diet resisted against NE-induced BW loss, ileal inflammation, and villus apoptosis. In conclusion, microbial metabolic product DCA prevents NE-induced BW loss and ileal inflammation through curbing inflammatory response. These novel findings could serve as a stepping-stone for developing next generation antimicrobial alternatives against NE.

microbiology↗