Impact of the gut microecology on Campylobacter presence revealed by comparisons of the gut microbiota from chickens raised on litter or in individual cages.

BACKGROUND: Poultry is the major reservoir of Campylobacter that contributes to human campylobacteriosis and threatens food safety. Litter contact has been linked to Campylobacter colonization, but the gut microecological impact underlying this link remains not fully clear. Here, we sought to investigate the impact of the gut microecology on the presence of Campylobacter by examining the microbiota in the duodenum, jejunum, ileum, ceca, and feces from chickens raised on commercial litter and in individual cages at 0-57 days of age. RESULTS: Through litter contact, the presence of Campylobacter was found to benefit from microecological competition among Lactobacillus, Helicobacter, and genera that are halotolerant and aerobic or facultatively anaerobic in the upper intestine, such as Corynebacterium and Brachybacterium. The presence was also promoted by the increased abundance in obligate anaerobic fermentation microbes, especially members of the orders Clostridiales and Bacteroidales. The longitudinal analysis supported the vertical or pseudo-vertical transmission but suggested that colonization might occur immensely at 7-28 days of age. We observed a host genetic effect on the gut microecology, which might lead to increased heterogeneity of the microecological impact on Campylobacter colonization. CONCLUSIONS: The findings advance the understanding of the gut microecological impact on Campylobacter presence in the chicken gut under conditions of litter contact and suggest that manipulations of the gut microecology, as well as the microbes identified in the Campylobacter association networks, might be important for the development of intervention strategies.

Enterotype identification and its influence on regulating the duodenum metabolism in chickens.

Enterotypes are used to describe clusters of specific gut microbial community structures, but few reports exist on the identification of enterotypes in poultry. In addition, there is incomplete understanding on the role of the foregut microbiota in the digestion and absorption of nutrients in poultry. Thus, this study aimed to identify the duodenal enterotypes by examining microbial communities from 206 broilers using 16S rRNA high-throughput sequencing and explore the effects of enterotypes on phenotypic performance and nutrient metabolism with metabolomics. The duodenal microbial communities of the broiler population were partitioned into 3 enterotypes (ET1, ET2, and ET3), and significant differences were observed in α-diversity among the enterotypes (P < 0.01). At the genus level, the ET1 group was over-represented by Bacteroides (9.8%) and Escherichia-Shigella (8.9%), the ET2 group was over-represented by Ochrobactrum (19.4%) and Rhodococcus (14.7%), and the ET3 group was over-represented by Bacillus (23.4%) and Akkermansia (16.2%). The relative abundance of the dominant taxa of each enterotype was significantly higher than that in the other 2 enterotypes (P < 0.01). The results showed that Ochrobactrum and Rhodococcus were positively correlated with cellobiose, alpha-D-glucose, D-mannose, and D-allose (r = 0.429, 0.435, 0.482, and 0.562, respectively; all P < 0.05). Rhodococcus was also positively correlated with tridecanoic acid and glycerol 1-myristate (r = 0.655 and 0.489, respectively; all P < 0.01). In terms of phenotype, the triglyceride level in the ET2 group was significantly higher than that in the ET1 group (P < 0.05), and the subcutaneous fat thickness and abdominal fat weight in the ET2 group were the highest (P > 0.05). Taken together, these results confirmed the presence of enterotypes in broilers and found that the dominant microbes in broilers of the ET2 group might play a major role in the degradation and utilization of plant polysaccharides, which may have an impact on the serum triglyceride level and fat deposition in broilers. These findings lay a foundation for further studies on the gut microbial interactions with the metabolism in broilers and the regulation of the gut microbiota to promote growth and well-being in broilers.