A Metagenomic Analysis of the Equine Gut Microbiome with and Without Probiotic Supplementation (P09-006-19).

Abstract

Objectives\nThe goal of this study is to compare the microbiome of domesticated horses with and without probiotic supplementation.\n\n\nMethods\nOur University s Institutional Animal Care and Use Committee has granted an exemption, as the horses were not housed on campus and there was no experimental manipulation to the horses feeding implemented. Fecal matter from six privately owned horses maintained on their standard grazing diet were collected. Three of the six horses received a probiotic supplement, SmartDigest, for several years prior to beginning the project. Supplementation ceased for one month, and samples were again obtained. The other three horses never received probiotics. Bacterial DNA was isolated from all fecal samples, the 16S rRNA gene amplified, tagged with index primers, and subsequently sequenced using the Illumina MiSeq.\n\n\nResults\nDominant groups from non-supplemented horses residing on the same property included the phyla bacteriodetes, firmicutes, proteobacteria, and verrucomicrobia. Interestingly, Sphingobacterium bambusae was identified in all three horses, even though this species has previously been isolated from the soil of bamboo plantations. Currently, samples from horses with probiotics are being analyzed. We are also employing qPCR analysis to validate the NextGen data, and to further investigate relative abundance of specific bacterial groups relevant to equine intestinal health.\n\n\nConclusions\nPreliminary NextGen sequence analysis of the relative abundance of bacterial phyla suggests that, as expected, the horses residing on the same property and thus receiving the same diet possess a similar intestinal microbiome composition. Similarities between horses persist down to the genus level, and are now being compared to samples from horses on a probiotic-supplemented diet.\n\n\nFunding Sources\nFinancial support was provided by Towson University s Fisher College of Science and Mathematics, and Jess and Mildred Fisher Endowed Chair funds to P. Tsuji.