Elucidating the Basis of Airway Protection By Gastrointestinal Lactobacillus Johnsonii
Tuesday, March 4, 2014
Exhibit Hall B (Convention Center)
Kaitlyn S. Lucey, PhD, Kei Fujimura, PhD, Marcus Rauch, PhD, Ali Faruqi, Douglas Fadrosh, Tine Demoor, PhD, Christine Cole Cole Johnson, PhD MPH FAAAAI, Homer A. Boushey Jr., MD FAAAAI, Edward M. Zoratti, M.D., FAAAAI, Dennis Ownby, M.D. FAAAAI, Nicholas W. Lukacs, PhD, Susan V. Lynch, PhD
Rationale: We recently demonstrated that the gram-positive, facultative anaerobe, L. johnsonii, is significantly enriched in the cecal microbiome of mice whose airways are protected against allergen and viral challenge, and that oral supplementation with this species alone can afford airway protection. Current studies are aimed at deciphering the basis for gastrointestinal L. johnsonii protection of the airways. Methods: L. johnsonii was isolated from airway protected mice, and its genome was sequenced using the Illumina MiSeq platform. The gut microbiome composition of mice supplemented with L. johnsonii was compared to unsupplemented animals, and used in conjunction with a metagenome predictive tool, PICRUSt, to compare the functional capacity of these communities. Results: L. johnsonii preferentially localizes in the terminal ileum and cecum. While its 16S rRNA is 99% homologous to L. johnsonii NCC 533, only 85% of the assembled contigs of its 2Mb genome are identical, suggesting that 15% of its genome is distinct from this species. Genes relevant to colonization, survival, and inter-species competition in the gut are present. Oral supplementation of mice with L. johnsonii is associated with significant enrichment of specific members of the Bacteroides, Proteobacteria, Firmicutes, Spirochaetes, Cyanobacteria, and Caldiserica (Welch's t-test p-value < 0.05, q-value < 0.16) and collectively this community imparts a myriad of immunomodulatory functions. Conclusion: L. johnsonii is a crucial species of the gut microbial community that reshapes community composition and function in a manner that affords airway protection in mice.