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Journal of veterinary internal medicine2025; 39(1); e17288; doi: 10.1111/jvim.17288

Characterization and comparison of fecal microbiota in horses with pituitary pars intermedia dysfunction and age-matched controls.

Abstract: Altered gut microbiota has been associated with dopaminergic degenerative diseases in people, but studies on horses with pituitary pars intermedia dysfunction (PPID) are lacking. Objective: Investigate the effect of PPID on fecal microbiota in horses. Methods: Nine horses with PPID and 13 age-matched control horses. Methods: Prospective control study. Fecal samples were collected bimonthly. Microbial analysis used 16S rRNA sequencing to determine the relative abundance at genus and phylum levels, assess alpha and beta diversity and identify core microbiota. Results: Horses with PPID had decreased relative abundances of Christensenellaceae R-7 group (median; 95% confidence interval [CI]: PPID, 2.04; 1.82-2.35 vs control, 2.54; 2.37-2.76; P = .02) and NK4A214 group (PPID, 2.21; 2.02-2.56 vs control, 2.62; 2.44-2.85; P = .05), and significant lower abundances of Romboutsia (log2FoldChange = -3.54; P = .04) and Peptococcaceae uncultured (log2FoldChange = -0.89; P = .04) by differential abundance analysis. However, the abundance of Fibrobacter (log2FoldChange = 0.74; P = .04) was significantly higher in the PPID group. A significant effect of PPID on beta diversity was observed (P = .004), whereas alpha diversity varied with months (P = .001). Seven unique genera were identified in horses with PPID and 12 in control horses. Conclusions: The fecal microbial composition is altered in horses with PPID. These findings support the potential role of the microbiota-gut-brain axis in the pathogenesis of PPID.
© 2025 The Author(s). Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
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Publication Date: 2025-01-24 PubMed ID: 39853825PubMed Central: PMC11758151DOI: 10.1111/jvim.17288Google Scholar: Lookup
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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.

This study investigates the impacts of pituitary pars intermedia dysfunction (PPID), a type of hormone disorder, on the composition of gut bacteria in horses, using sequencing technologies to identify different bacterial populations.

Objective and Methodology

  • The primary aim of this study was to explore how PPID affects the fecal microbiota in horses. To do so, researchers examined fecal samples from nine horses diagnosed with PPID, comparing them with samples from 13 healthy control horses of the same age.
  • The study was designed as a prospective control study, where the fecal samples were collected at regular two-month intervals.
  • The research team used 16S rRNA sequencing, a common method for studying bacterial populations. This approach allowed them to determine the relative abundance of different bacteria at the genus and phylum levels, examine alpha and beta diversity, and identify key components of the microbiota.

Key Findings

  • The research findings indicated significant differences in the makeup of the fecal microbiota between horses with PPID and the control group.
  • Certain bacteria groups – such as the Christensenellaceae R-7 group and NK4A214 group – showed decreased abundance in horses with PPID, while the abundance of a genus called Fibrobacter was significantly higher in the PPID group.
  • Results also showed a significant effect of PPID on beta diversity (a measure of variation in community composition), and the alpha diversity (a measure of species diversity in a community) was observed to vary with months.
  • The team identified seven unique bacterial genera in horses with PPID and 12 unique genera in the control horses.

Conclusion

  • This research demonstrated that PPID alters the composition of the fecal microbiota in horses. Such findings reinforce the idea of a potential role for the microbiota-gut-brain axis in the development of PPID.
  • The precise relationships between hormonal disorders like PPID, gut microbiota, and neurological health remain to be further explored in future studies.

Cite This Article

APA
Wang W, Gibson J, Horsman S, Mikkelsen D, Bertin FR. (2025). Characterization and comparison of fecal microbiota in horses with pituitary pars intermedia dysfunction and age-matched controls. J Vet Intern Med, 39(1), e17288. https://doi.org/10.1111/jvim.17288

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 39
Issue: 1
Pages: e17288
PII: e17288

Researcher Affiliations

Wang, Wenqing
  • School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Gibson, Justine
  • School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Horsman, Sara
  • School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Mikkelsen, Deirdre
  • School of Agriculture and Food Sciences, The University of Queensland, St Lucia, Queensland, Australia.
Bertin, François-René
  • School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
  • College of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA.

MeSH Terms

  • Animals
  • Horses
  • Feces / microbiology
  • Horse Diseases / microbiology
  • Pituitary Gland, Intermediate / microbiology
  • Pituitary Diseases / veterinary
  • Pituitary Diseases / microbiology
  • Case-Control Studies
  • Male
  • Female
  • RNA, Ribosomal, 16S / genetics
  • Gastrointestinal Microbiome
  • Prospective Studies

Grant Funding

  • Australian Companion Animal Health Foundation

Conflict of Interest Statement

Authors declare no conflict of interest.

References

This article includes 47 references
  1. Ireland JL, McGowan CM. Epidemiology of pituitary pars intermedia dysfunction: a systematic literature review of clinical presentation, disease prevalence and risk factors.. Vet J 2018;235:22‐33.
    pubmed: 29704935
  2. McGowan TW, Pinchbeck GP, McGowan CM. Prevalence, risk factors and clinical signs predictive for equine pituitary pars intermedia dysfunction in aged horses.. Equine Vet J 2013;45:74‐79.
    pubmed: 22594955
  3. Fortin JS, Benskey MJ, Lookingland KJ. Restoring pars intermedia dopamine concentrations and tyrosine hydroxylase expression levels with pergolide: evidence from horses with pituitary pars intermedia dysfunction.. BMC Vet Res 2020;16:356.
    pmc: PMC7517620pubmed: 32977825
  4. Huang L, Palmieri C, Bertin FR. Correlation of pituitary histomorphometry with dopamine and dopamine D2 receptor expression in horses with pituitary pars intermedia dysfunction.. Res Vet Sci 2022;152:427‐433.
    pubmed: 36126509
  5. Anis E, Xie A, Brundin L, Brundin P. Digesting recent findings: gut alpha‐synuclein, microbiome changes in Parkinson's disease.. Trends Endocrinol Metab 2022;33:147‐157.
    pubmed: 34949514
  6. Poewe W, Seppi K, Tanner CM. Parkinson disease.. Nat Rev Dis Primers 2017;3:17013.
    pubmed: 28332488
  7. Schwiertz A, Spiegel J, Dillmann U. Fecal markers of intestinal inflammation and intestinal permeability are elevated in Parkinson's disease.. Parkinsonism Relat Disord 2018;50:104‐107.
    pubmed: 29454662
  8. Unger MM, Spiegel J, Dillmann KU. Short chain fatty acids and gut microbiota differ between patients with Parkinson's disease and age‐matched controls.. Parkinsonism Relat Disord 2016;32:66‐72.
    pubmed: 27591074
  9. Lubomski M, Tan AH, Lim SY, Holmes AJ, Davis RL, Sue CM. Parkinson's disease and the gastrointestinal microbiome.. J Neurol 2020;267:2507‐2523.
    pubmed: 31041582
  10. Pellegrini C, Fornai M, Colucci R. Alteration of colonic excitatory tachykininergic motility and enteric inflammation following dopaminergic nigrostriatal neurodegeneration.. J Neuroinflammation 2016;13:146.
    pmc: PMC4907252pubmed: 27295950
  11. Natale G, Kastsiushenka O, Fulceri F, Ruggieri S, Paparelli A, Fornai F. MPTP‐induced parkinsonism extends to a subclass of TH‐positive neurons in the gut.. Brain Res 2010;1355:195‐206.
    pubmed: 20691673
  12. Houser MC, Tansey MG. The gut‐brain axis: is intestinal inflammation a silent driver of Parkinson's disease pathogenesis?. NPJ Parkinsons Dis 2017;3:3.
    pmc: PMC5445611pubmed: 28649603
  13. McFarlane D, Dybdal N, Donaldson MT, Miller L, Cribb AE. Nitration and increased alpha‐synuclein expression associated with dopaminergic neurodegeneration in equine pituitary pars intermedia dysfunction.. J Neuroendocrinol 2005;17:73‐80.
    pubmed: 15796757
  14. Fortin JS, Hetak AA, Duggan KE, Burglass CM, Penticoff HB, Schott HC II. Equine pituitary pars intermedia dysfunction: a spontaneous model of synucleinopathy.. Sci Rep 2021;11:16036.
    pmc: PMC8346493pubmed: 34362943
  15. McFarlane D, Hale GM, Johnson EM, Maxwell LK. Fecal egg counts after anthelmintic administration to aged horses and horses with pituitary pars intermedia dysfunction.. J Am Vet Med Assoc 2010;236:330‐334.
    pubmed: 20113248
  16. Horn R, Stewart AJ, Jackson KV, Dryburgh EL, Medina‐Torres CE, Bertin FR. Clinical implications of using adrenocorticotropic hormone diagnostic cutoffs or reference intervals to diagnose pituitary pars intermedia dysfunction in mature horses.. J Vet Intern Med 2021;35:560‐570.
    pmc: PMC7848300pubmed: 33368633
  17. Vorster DM, Wang W, Kemp KL, Bamford NJ, Bertin FR. Clinical implications of imprecise sampling time for 10‐ and 30‐min thyrotropin‐releasing hormone stimulation tests in horses.. Equine Vet J 2024;56:291‐298.
    pubmed: 37649416
  18. Hu K, Stewart AJ, Yuen KY, Hinrichsen S, Dryburgh EL, Bertin FR. The effect of freeze‐thaw cycles on determination of immunoreactive plasma adrenocorticotrophic hormone concentrations in horses.. J Vet Intern Med 2020;34:1350‐1356.
    pmc: PMC7255672pubmed: 32255541
  19. Engelbrektson A, Kunin V, Wrighton KC. Experimental factors affecting PCR‐based estimates of microbial species richness and evenness.. ISME J 2010;4:642‐647.
    pubmed: 20090784
  20. Bolyen E, Rideout JR, Dillon MR. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2.. Nat Biotechnol 2019;37:852‐857.
    pmc: PMC7015180pubmed: 31341288
  21. Quast C, Pruesse E, Yilmaz P. The SILVA ribosomal RNA gene database project: improved data processing and web‐based tools.. Nucleic Acids Res 2013;41:D590‐D596.
    pmc: PMC3531112pubmed: 23193283
  22. Weinert‐Nelson JR, Biddle AS, Sampath H, Williams CA. Fecal microbiota, forage nutrients, and metabolic responses of horses grazing warm‐ and cool‐season grass pastures.. Animals (Basel) 2023;13:790.
    pmc: PMC10000167pubmed: 36899650
  23. Boucher L, Leduc L, Leclere M. Current understanding of equine gut dysbiosis and microbiota manipulation techniques: comparison with current knowledge in other species.. Animals (Basel) 2024;14:758.
    pmc: PMC10931082pubmed: 38473143
  24. Dalile B, Van Oudenhove L, Vervliet B. The role of short‐chain fatty acids in microbiota‐gut‐brain communication.. Nat Rev Gastroenterol Hepatol 2019;16:461‐478.
    pubmed: 31123355
  25. Daly K, Proudman CJ, Duncan SH, Flint HJ, Dyer J, Shirazi‐Beechey SP. Alterations in microbiota and fermentation products in equine large intestine in response to dietary variation and intestinal disease.. Br J Nutr 2012;107:989‐995.
    pubmed: 21816118
  26. Ayoub C, Arroyo LG, MacNicol JL. Fecal microbiota of horses with colitis and its association with laminitis and survival during hospitalization.. J Vet Intern Med 2022;36:2213‐2223.
    pmc: PMC9708523pubmed: 36271677
  27. Plassais J, Gbikpi‐Benissan G, Figarol M. Gut microbiome alpha‐diversity is not a marker of Parkinson's disease and multiple sclerosis.. Brain Commun 2021;3:fcab113.
    pmc: PMC8195527pubmed: 34704023
  28. Lozupone CA, Stombaugh JI, Gordon JI, Jansson JK, Knight R. Diversity, stability and resilience of the human gut microbiota.. Nature 2012;489:220‐230.
    pmc: PMC3577372pubmed: 22972295
  29. Tuniyazi M, He J, Guo J. Changes of microbial and metabolome of the equine hindgut during oligofructose‐induced laminitis.. BMC Vet Res 2021;17:11.
    pmc: PMC7789226pubmed: 33407409
  30. Varesi A, Campagnoli LIM, Fahmideh F. The interplay between gut microbiota and Parkinson's disease: implications on diagnosis and treatment.. Int J Mol Sci 2022;23:12289.
    pmc: PMC9603886pubmed: 36293176
  31. Lindenberg F, Krych L, Fielden J. Expression of immune regulatory genes correlate with the abundance of specific Clostridiales and Verrucomicrobia species in the equine ileum and cecum.. Sci Rep 2019;9:12674.
    pmc: PMC6722064pubmed: 31481726
  32. Romano S, Savva GM, Bedarf JR, Charles IG, Hildebrand F, Narbad A. Meta‐analysis of the Parkinson's disease gut microbiome suggests alterations linked to intestinal inflammation.. NPJ Parkinsons Dis 2021;7:27.
    pmc: PMC7946946pubmed: 33692356
  33. Desai MS, Seekatz AM, Koropatkin NM. A dietary fiber‐deprived gut microbiota degrades the colonic mucus barrier and enhances pathogen susceptibility.. Cell 2016;167:1339‐1353.e21.
    pmc: PMC5131798pubmed: 27863247
  34. Hutfless S, Wenning GK. Inflammatory bowel disease increases the risk of Parkinson's disease: a Danish nationwide cohort study 1977‐2014.. Gut 2019;68:3.
    pubmed: 29785965
  35. Weimers P, Halfvarson J, Sachs MC. Inflammatory bowel disease and Parkinson's disease: a nationwide Swedish cohort study.. Inflamm Bowel Dis 2019;25:111‐123.
    pubmed: 29788069
  36. Park S, Kim J, Chun J. Patients with inflammatory bowel disease are at an increased risk of Parkinson's disease: a South Korean nationwide population‐based study.. J Clin Med 2019;8:1191.
    pmc: PMC6723604pubmed: 31398905
  37. Lin JC, Lin CS, Hsu CW, Lin CL, Kao CH. Association between Parkinson's disease and inflammatory bowel disease: a nationwide Taiwanese retrospective cohort study.. Inflamm Bowel Dis 2016;22:1049‐1055.
    pubmed: 26919462
  38. Zaitseva S, Dagurova O, Radnagurueva A. Fecal microbiota and diet composition of Buryatian horses grazing warm‐ and cold‐season grass pastures.. Microorganisms 2023;11:1947.
    pmc: PMC10459317pubmed: 37630507
  39. Salem SE, Maddox TW, Berg A. Variation in faecal microbiota in a group of horses managed at pasture over a 12‐month period.. Sci Rep 2018;8:8510.
    pmc: PMC5981443pubmed: 29855517
  40. Koliada A, Moseiko V, Romanenko M. Seasonal variation in gut microbiota composition: cross‐sectional evidence from Ukrainian population.. BMC Microbiol 2020;20:100.
    pmc: PMC7175530pubmed: 32316935
  41. You Z, Deng J, Liu J. Seasonal variations in the composition and diversity of gut microbiota in white‐lipped deer (Cervus albirostris).. PeerJ 2022;10:e13753.
    pmc: PMC9302429pubmed: 35873913
  42. Springer A, Fichtel C, Al‐Ghalith GA. Patterns of seasonality and group membership characterize the gut microbiota in a longitudinal study of wild Verreaux's sifakas (Propithecus verreauxi).. Ecol Evol 2017;7:5732‐5745.
    pmc: PMC5551086pubmed: 28808547
  43. Morrison PK, Newbold CJ, Jones E. The equine gastrointestinal microbiome: impacts of age and obesity.. Front Microbiol 2018;9:3017.
    pmc: PMC6293011pubmed: 30581426
  44. Grimm P, Philippeau C, Julliand V. Faecal parameters as biomarkers of the equine hindgut microbial ecosystem under dietary change.. Animal 2017;11:1136‐1145.
    pubmed: 28065211
  45. Costa MC, Stampfli HR, Arroyo LG. Changes in the equine fecal microbiota associated with the use of systemic antimicrobial drugs.. BMC Vet Res 2015;11:19.
    pmc: PMC4323147pubmed: 25644524
  46. Mach N, Ruet A, Clark A. Priming for welfare: gut microbiota is associated with equitation conditions and behavior in horse athletes.. Sci Rep 2020;10:8311.
    pmc: PMC7239938pubmed: 32433513
  47. Dougal K, de la Fuente G, Harris PA. Characterisation of the faecal bacterial community in adult and elderly horses fed a high fibre, high oil or high starch diet using 454 pyrosequencing.. PLoS One 2014;9:e87424.
    pmc: PMC3913607pubmed: 24504261

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