Takeshita Nachiko, Watanabe Takayasu, Ishida-Kuroki Kasumi, Sekizaki Tsutomu
Research Center for Food Safety, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113-8657, Japan.
Present Address: Department of Chemistry, Nihon University School of Dentistry, Kanda-Surugadai 1-8-13, Chiyoda-ku, Tokyo, 101-8310, Japan.
BMC Vet Res. 2021 Jan 6;17(1):10. doi: 10.1186/s12917-020-02688-7.
Chickens are major sources of human nutrition worldwide, but the chicken intestinal microbiota can be a source of bacterial infection. The microbiota has potential to regulate the colonization of pathogens by competitive exclusion, production of antimicrobial compounds, and stimulation of the mucosal immune system. But information on the microbiota in commercial broiler chickens is limited because of the difficulty of conducting studies at commercial farms. To obtain fundamental information that can be used to control pathogens in chickens, we determined the 6-week dynamics of microbiota in chicken cecal droppings from commercial broiler farms.
Cecal droppings from four chickens were collected once a week from 1 to 6 weeks of age at three commercial broiler farms. A total of 168 samples were collected from 7 flocks and subjected to 16S rRNA amplicon sequencing. Despite the farms have distinctly different climate conditions, the microbiota in the same growth stages were similar among farms. Moreover, as the chickens grew and the feed types were switched, the richness and diversity of the microbiota gradually increased and convergence of the composition of the microbiota was apparent. Notably, minor bacterial taxa (i.e. OTUs with relative abundance < 0.05%) within the microbiota were changed by the chicken age, switching of feed types, and presence of Campylobacter. In particular, the effects of switching of feed types on the microbiota were larger than the effects of age and Campylobacter.
Irrespective of the locations of the farms, the microbiota of chicken cecum, especially minor bacteria, was successively changed more affected by feed types than by ages. Switching of feed types inducing the alteration of the microbiota may be associated with the colonization of pathogens in the chicken gut. These results will also help with extrapolation of studies in experimental animals to those in the commercial farms.
鸡是全球人类营养的主要来源，但鸡肠道微生物群可能是细菌感染的源头。微生物群有潜力通过竞争排斥、产生抗菌化合物以及刺激黏膜免疫系统来调节病原体的定植。然而，由于在商业农场开展研究存在困难，关于商业肉鸡微生物群的信息有限。为了获得可用于控制鸡体内病原体的基础信息，我们测定了商业肉鸡场鸡盲肠粪便中微生物群在6周内的动态变化。
在三个商业肉鸡场，从1至6周龄的鸡中每周收集一次四只鸡的盲肠粪便。从7个鸡群中总共收集了168个样本，并进行16S rRNA扩增子测序。尽管各农场气候条件明显不同，但同一生长阶段各农场的微生物群相似。此外，随着鸡的生长和饲料类型的转换，微生物群的丰富度和多样性逐渐增加，微生物群组成的趋同明显。值得注意的是，微生物群中的次要细菌分类群（即相对丰度<0.05%的OTU）会因鸡的年龄、饲料类型的转换和弯曲杆菌的存在而发生变化。特别是，饲料类型转换对微生物群的影响大于年龄和弯曲杆菌的影响。
无论农场位置如何，鸡盲肠的微生物群，尤其是次要细菌，其相继变化受饲料类型的影响大于年龄。饲料类型的转换诱导微生物群的改变可能与鸡肠道中病原体的定植有关。这些结果也将有助于将实验动物的研究外推至商业农场的研究。
