title: Molecular analysis of autochthonous microbiota along the digestive tract of juvenile grouper Epinephelus coioides following probiotic Bacillus pumilus administration.
abstract: OBJECTIVE
  To evaluate the diversity of dominant autochthonous microbiota along the digestive tract of juvenile Epinephelus coioides following the dietary administration of probiotic Bacillus pumilus for 60 days.
  
  
  RESULTS
  Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) with subsequently sequencing analysis was used to assess the gut microbiota. Generally similar DGGE patterns were observed in the foregut, midgut and hindgut of E. coioides, while the similarity dendrogram clearly revealed three different clusters depending on the three compartments of the GI tract. Dietary administration of B. pumilus stimulated its colonization in each compartment of the digestive tract. Samples collected from the probiotic group and the control group showed similar DGGE patterns, and no significant difference in the total number of bands and the Shannon index were detected between the probiotic group and the control group, suggested that B. pumilus exert no significant effect on the gut microbiota. However, various potentially beneficial bacteria, such as uncultured Bacillus sp. clone QJNY94-like, Nitratireductor sp. YCSC5-like, Methylobacterium hispanicum-like and Microbacterium sp. YACS1-like bacteria were stimulated by probiotic B. pumilus, while the potential harmful Staphylococcus saprophyticus-like bacterium was depressed.
  
  
  CONCLUSIONS
  Autochthonous gut microbiota of E. coioides was modulated to some degree, not significant, by probiotic B. pumilus, various potentially beneficial bacteria were selectively stimulated, while one potential harmful species was depressed.
  
  
  CONCLUSIONS
  This work represents the first report that dietary administration of probiotic B. pumilus modulated the gut microbiota of E. coioides. These findings broaden our understanding of probiotic effects at the gut level, which is helpful in understanding the mechanisms that underpin host benefits.
authors.affiliation: The Key Laboratory of Science and Technology for Aquaculture and Food Safety of Fujian Province University, Fisheries College, Jimei University, Xiamen, China The Key Laboratory for Feed Quality Testing and Safety Evaluation of Xiamen, Fisheries College, Jimei University, Xiamen, China.
authors.forename: Y-Z
authors.initials: YZ
authors.lastname: Sun
authors.forename: H-L
authors.initials: HL
authors.lastname: Yang
authors.forename: R-L
authors.initials: RL
authors.lastname: Ma
authors.forename: K
authors.initials: K
authors.lastname: Song
authors.forename: W-Y
authors.initials: WY
authors.lastname: Lin
mesh_terms: D000818:Animals; D001407:Bacillus; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D001492:Bass / Q000254:growth & development / Q000382:microbiology*; D058645:Denaturing Gradient Gel Electrophoresis; D041981:Gastrointestinal Tract / Q000382:microbiology*; D064307:Microbiota; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D019936:Probiotics / Q000008:administration & dosage*