AUTHOR=Adhikari Bishnu , Kwon Young M. 

TITLE=Characterization of the Culturable Subpopulations of Lactobacillus in the Chicken Intestinal Tract as a Resource for Probiotic Development

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.01389

DOI=10.3389/fmicb.2017.01389

ISSN=1664-302X

ABSTRACT=<p>To gain better understanding of the distributions of the culturable <italic>Lactobacillus</italic> species in the chicken intestinal tract, we collected ceca, and distal ileum from 10 3-weeks-old broiler chickens. <italic>Lactobacillus</italic> strains from cecal lumen contents (M-CL), and those associated with mucosa of ceca (M-CM) and ileum (M-IM) were recovered on de Man, Rogosa and Sharpe (MRS) agar plates, and used for microbiota analysis. The total cecal content (T-CL) was also used directly for microbiota analysis. We purposefully focused on MRS-recovered populations to gain understanding of the culturable subpopulations of <italic>Lactobacillus</italic>, since the culturability is an important phenotype in order to exploit the chicken gut microbiota as a resource for development of probiotics. The V1–V3 regions of 16S rRNA gene was amplified from genomic DNA samples, and the pooled amplicons were analyzed by MiSeq sequencing with paired-end read 300 cycle option. Among MRS groups, <italic>Firmicutes</italic> were significantly higher in M-IM and M-CL as compared to M-CM, whereas <italic>Proteobacteria</italic> were significantly higher in M-CM as compared to M-IM and M-CL at <italic>p</italic> &lt; 0.05. Among <italic>Lactobacillus</italic>, <italic>L. salivarius</italic> (36%) and <italic>L. johnsonii</italic> (21%) were higher in M-IM as compared to M-CL (<italic>L. salivarius</italic>, 28%; <italic>L. johnsonii</italic>, 15%), and M-CM (<italic>L. salivarius</italic>, 20%; <italic>L. johnsonii</italic>, 11%). <italic>L. crispatus</italic> was found significantly higher in M-CL as compared to M-IM (<italic>p</italic> &lt; 0.01) whereas <italic>L. gasseri</italic> was found significantly higher in M-IM as compared to M-CM (<italic>p</italic> &lt; 0.05). <italic>L. aviarius</italic>, and <italic>L. fornicalis</italic> were only observed in T-CL. In summary, <italic>Lactobacillus</italic> populations recovered on MRS vary with different regions and locations in chicken GIT, which might indicate their distinct functional roles in different gastrointestinal tract (GIT) niches, and some species of <italic>Lactobacillus</italic> are not culturable on MRS agar media. This study is the first attempt to define culturable <italic>Lactobacillus</italic> subpopulations in the chicken intestinal tract comprehensively using 16S rRNA gene profiling, and the findings of this study will be used as a platform to develop a new strategy for isolation of effective <italic>Lactobacillus</italic> probiotic candidates based on comparative analyses of chicken gut microbiota.</p>