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Animals : an open access journal from MDPI2021; 11(6); 1807; doi: 10.3390/ani11061807

Alterations in the Fecal Microbiome and Metabolome of Horses with Antimicrobial-Associated Diarrhea Compared to Antibiotic-Treated and Non-Treated Healthy Case Controls.

Abstract: Diarrhea is an adverse effect of antimicrobial therapy in horses. This matched, case-controlled study compared the fecal microbiome and metabolome of horses on antibiotics that developed diarrhea (AAD, = 17) to those that did not develop diarrhea (ABX, = 15) and to a control population not exposed to antibiotics (CON, = 31). Fecal samples were collected from horses that were matched for diet and antimicrobial agent (including dose, route, and duration of therapy). Illumina sequencing of 16S rRNA genes was performed, and QIIME 2.0 was used to generate alpha and beta diversity metrics. Untargeted metabolomics using GC-MS platforms was performed and analyzed using Metaboanalyst 5.0. Microbiome composition was significantly different in AAD compared to CON (ANOSIM, R = 0.568, = 0.001) but not to ABX (ANOSIM, R = 0.121, = 0.0012). AAD and ABX horses had significantly decreased richness and evenness compared to CON horses ( < 0.05). Horses on antimicrobials (AAD and ABX) had significant changes in 14 phyla compared to CON horses. Only Verrucomicrobia distinguished AAD from ABX and CON horses (q = 0.0005). Metabolite profiles of horses with AAD clustered separately from ABX and CON horses. Seven metabolites were found to be significantly different between groups ( < 0.05): L-tyrosine, kynurenic acid, xanthurenic acid, 5-hydroxyindole-3-acetic acid, docosahexaenoic acid ethyl ester, daidzein, and N-acetyltyramine. Metabolite profiles of horses on antimicrobials, especially those with AAD, are altered compared to CON horses.
Publication Date: 2021-06-17 PubMed ID: 34204371PubMed Central: PMC8235368DOI: 10.3390/ani11061807Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research examines the ways in which the use of antimicrobials in horses affect their digestive systems, comparing those that developed diarrhea to those that did not. The study finds instances of significant changes in the microbiome and metabolome compositions of horses on antimicrobials.

Research Methodology

  • The research employs a matched, case-controlled study, comparing fecal samples from three groups of horses: those on antibiotics that developed diarrhea (AAD), those on antibiotics that did not develop diarrhea (ABX), and those not exposed to antibiotics (CON).
  • The horses in each group were matched for diet and the type of antimicrobial agent used, including the dose, route, and duration of the therapy.
  • The samples were analyzed using Illumina sequencing of 16S rRNA genes, and QIIME 2.0 was used to generate alpha and beta diversity metrics.
  • Further analysis was performed using untargeted metabolomics using GC-MS platforms, and the data generated was analyzed using Metaboanalyst 5.0.

Research Findings

  • The composition of the microbiome was found to be significantly different in AAD horses compared to the CON group, but not compared to the ABX group.
  • Moreover, both AAD and ABX horses displayed significantly decreased richness and evenness in their microbiomes compared to the CON group.
  • In terms of the microbiome composition at the phyla level, significant changes in 14 phyla were noted in horses on antibiotics (AAD and ABX) compared to the CON group. Verrucomicrobia distinguished AAD horses from ABX and CON horses.
  • Metabolite profiles of horses with AAD clustered separately from ABX and CON horses, suggesting alterations in the metabolome due to the onset of diarrhea.
  • Seven metabolites were found to be significantly different between groups: L-tyrosine, kynurenic acid, xanthurenic acid, 5-hydroxyindole-3-acetic acid, docosahexaenoic acid ethyl ester, daidzein, and N-acetyltyramine.

Conclusion

  • The research concludes that the metabolite profiles of horses on antimicrobials, especially those with AAD, are altered compared to CON horses, indicating a significant effect of antimicrobial therapy on the horse’s intestinal microbiota and metabolites.

Cite This Article

APA
Arnold C, Pilla R, Chaffin K, Lidbury J, Steiner J, Suchodolski J. (2021). Alterations in the Fecal Microbiome and Metabolome of Horses with Antimicrobial-Associated Diarrhea Compared to Antibiotic-Treated and Non-Treated Healthy Case Controls. Animals (Basel), 11(6), 1807. https://doi.org/10.3390/ani11061807

Publication

ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 11
Issue: 6
PII: 1807

Researcher Affiliations

Arnold, Carolyn
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Pilla, Rachel
  • Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Chaffin, Keith
  • Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Lidbury, Jonathan
  • Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Steiner, Joerg
  • Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Suchodolski, Jan
  • Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.

Conflict of Interest Statement

The authors declare no conflict of interest.

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