title: Effects ofBacillus subtilisCSL2 on the composition and functional diversity of the faecal microbiota of broiler chickens challenged withSalmonellaGallinarum.
abstract: BACKGROUND
  The chicken gastrointestinal tract contains a diverse microbiota whose composition and structure play important roles in gut functionality. In this study, microbial shifts resulting from feed supplementation withBacillus subtilisCSL2 were evaluated in broilers challenged and unchallenged withSalmonellaGallinarum. To analyse bacterial community composition and functionality, 454 GS-FLX pyrosequencing of 16S rRNA gene amplicons was performed.
  
  
  RESULTS
  The Quantitative Insights into Microbial Ecology (QIIME) pipeline was used to analyse changes in the faecal microbiota over a 24-h period. A total of 718,204 sequences from broiler chickens were recorded and analysed. At the phylum level, Firmicutes, Bacteroidetes, and Proteobacteria were the predominant bacterial taxa. InSalmonella-infected chickens (SC), Bacteroidetes were more highly abundant compared to control (NC) andBacillus-treated (BT) chickens. At the genus level, in the NC and BT groups,Lactobacilluswas present at high abundance, and the abundance ofTuricibacter, unclassifiedEnterobacteriaceae, andBacteroidesincreased in SC broilers. Furthermore, taxon-independent analysis showed that the SC and BT groups were compositionally distinct at the end of the 24-h period. Further analysis of functional properties showed thatB. subtilisCSL2 administration increased gut-associated energy supply mechanisms (i.e. carbohydrate transport and metabolism) to maintain a stable microbiota and protect gut integrity.
  
  
  CONCLUSIONS
  This study demonstrated thatS.Gallinarum infection andB. subtilisCSL2 supplementation in the diet of broiler chickens influenced the diversity, composition, and functional diversity of the faecal microbiota. Moreover, the findings offer significant insights to understand potential mechanisms ofSalmonellainfection and the mode of action of probiotics in broiler chickens.
authors.affiliation: Department of Animal Resources Science, Dankook University, 119 Dandae-ro, Cheonan, 31116 Republic of Korea.
authors.forename: Ju Kyoung
authors.initials: JK
authors.lastname: Oh
authors.affiliation: Department of Animal Resources Science, Dankook University, 119 Dandae-ro, Cheonan, 31116 Republic of Korea.
authors.forename: Edward Alain B
authors.initials: EAB
authors.lastname: Pajarillo
authors.affiliation: Department of Animal Resources Science, Dankook University, 119 Dandae-ro, Cheonan, 31116 Republic of Korea.
authors.forename: Jong Pyo
authors.initials: JP
authors.lastname: Chae
authors.affiliation: Department of Animal Resources Science, Dankook University, 119 Dandae-ro, Cheonan, 31116 Republic of Korea.
authors.forename: In Ho
authors.initials: IH
authors.lastname: Kim
authors.affiliation: Abson BioChem, Inc, 10-1 Yangjimaeul-gil, Sangrok-gu, Ansan, 15524 Republic of Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Yang
authors.affiliation: Department of Animal Resources Science, Dankook University, 119 Dandae-ro, Cheonan, 31116 Republic of Korea.
authors.forename: Dae-Kyung
authors.initials: DK
authors.lastname: Kang
keywords: 16S rRNA gene; Bacillus subtilis; Broiler chicken; Microbiome; Salmonella Gallinarum