Microbiome and Dental Changes in Horses Fed a High Soluble Carbohydrate Diet.
Abstract: This study investigated the oral microbiome of horses maintained on a high soluble carbohydrate diet based on sugarcane, in comparison to those fed a pasture-based diet composed of spp., aiming to identify associations between dietary intake, the composition of oral microbial communities, and the occurrence of dental caries and diastemata. A total of 20 healthy horses, both male and female, with an average age of 9 ± 3 years and weight of 400 ± 100 kg, without a defined breed, were selected. They were divided into two groups: the High Soluble Carbohydrate Group (HSCCG), consisting of 10 horses fed sugarcane for at least 3 years, and the Low Soluble Carbohydrate Group (LSCCG), consisting of 10 horses fed pasture with spp. Dental examinations were performed using an adapted oral endoscope to assess caries and diastemata, and saliva samples were collected for microbiota analysis. Statistical analyses included a Student's -test and Mann-Whitney test, with significance set at < 0.05. Horses in the HSCCG had a higher presence of peripheral caries ( = 0.001), as well as differences in the degree ( = 0.010), class ( = 0.05), and presence of diastemata. Microbial diversity indices (Chao, inverse Simpson, and Shannon) showed no significant differences, but the relative abundance differed ( = 0.003). Linear Discriminant Analysis revealed distinct microbial profiles: Candidatus Saccharibacteria and Bacteroidetes were more abundant in the HSCCG, while Cyanobacteria_Chloroplast and Proteobacteria dominated in the LSCCG. Over 35 genera differed significantly between groups. The study concludes that diet plays a significant role in shaping oral microbiota and influencing the development of dental caries in horses.
Publication Date: 2025-08-29 PubMed ID: 40941342PubMed Central: PMC12427182DOI: 10.3390/ani15172547Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- 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.
Overview
- This study explored how a high soluble carbohydrate diet, primarily sugarcane, affects the oral microbiome and dental health of horses compared to a pasture-based diet.
- The research specifically examined the association between diet, oral microbial communities, and the prevalence of dental caries (tooth decay) and diastemata (gaps between teeth).
Study Design and Subject Details
- A total of 20 healthy horses were selected, with an average age of 9 ± 3 years and weight of 400 ± 100 kg, including both males and females without a specific breed.
- The horses were separated into two groups:
- High Soluble Carbohydrate Group (HSCCG): 10 horses fed a sugarcane-based diet for at least 3 years.
- Low Soluble Carbohydrate Group (LSCCG): 10 horses fed a pasture-based diet predominantly consisting of native pasture grasses.
Methods of Assessment
- Dental examinations were carried out using an adapted oral endoscope, allowing visualization and assessment of:
- Dental caries (specifically peripheral caries)
- Diastemata (the presence and characteristics of gaps between teeth)
- Saliva samples were collected from all horses to analyze the oral microbiota composition through microbial diversity indices and relative abundance measurements.
- Statistical analyses to compare groups included:
- Student’s t-test
- Mann-Whitney test
- Significance threshold was set at p < 0.05
Key Findings on Dental Health
- Horses in the HSCCG (high sugarcane diet) showed:
- A significantly higher presence of peripheral dental caries (p = 0.001)
- Differences in the degree of diastemata severity (p = 0.010)
- Variations in the class and presence of diastemata (p = 0.05)
- The LSCCG (pasture-fed horses) had fewer signs of dental decay and less pronounced diastemata, indicating better dental health associated with low soluble carbohydrate intake.
Oral Microbiota Analysis
- Microbial diversity, measured using indices such as Chao, inverse Simpson, and Shannon indices, showed no significant differences between groups, suggesting similar overall richness and diversity of microbial species.
- However, the relative abundance of microbial taxa significantly differed (p = 0.003), indicating variations in the specific composition of microbial communities due to diet.
- Linear Discriminant Analysis (LDA) insights:
- HSCCG horses had higher abundance of certain bacterial groups, notably:
- Candidatus Saccharibacteria
- Bacteroidetes
- LSCCG horses had a higher presence of:
- Cyanobacteria_Chloroplast
- Proteobacteria
- More than 35 bacterial genera showed significant differential abundance between the two groups.
- HSCCG horses had higher abundance of certain bacterial groups, notably:
Conclusions and Implications
- The type of diet, particularly a high soluble carbohydrate intake from sugarcane, has a marked influence on the composition of the oral microbiome in horses.
- These microbial changes are associated with an increased risk and presence of dental caries and changes in diastemata characteristics.
- Maintaining a pasture-based diet may help preserve a healthier oral microbial balance and reduce the incidence of dental diseases in horses.
- The findings highlight the importance of diet management in equine dental health and suggest potential microbiota targets for preventing or managing oral disease.
Cite This Article
APA
Lacerenza MD, Arantes JA, Reginato GM, Finardi GLF, Marchi PH, Vendramini THA, Corrêa RR, Pereira PAM, Valadão CAA, Dória RGS.
(2025).
Microbiome and Dental Changes in Horses Fed a High Soluble Carbohydrate Diet.
Animals (Basel), 15(17), 2547.
https://doi.org/10.3390/ani15172547 Publication
Researcher Affiliations
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Pet Nutrology Research Center (CEPEN Pet), Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Pet Nutrology Research Center (CEPEN Pet), Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Pet Nutrology Research Center (CEPEN Pet), Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Teaching and Research Support Center (CAEP), School of Veterinary Medicine and Animal Science, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
- Faculty of Agricultural and Veterinary Sciences, Sao Paulo State University, Jaboticabal 14884-900, SP, Brazil.
- Faculty of Agricultural and Veterinary Sciences, Sao Paulo State University, Jaboticabal 14884-900, SP, Brazil.
- Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
Grant Funding
- 2020/09633-0 / São Paulo Research Foundation (FAPESP)
- 309701/2022-8 / National Council for Scientific and Technological Development (CNPQ)
- 001 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES)
Conflict of Interest Statement
The authors declare no conflicts of interest.
References
This article includes 36 references
- Lundström T, Birkhed D. Equine peripheral cemental defects and dental caries: Four case reports.. Equine Vet. Educ. 2020;33:e161–e166.
- Dixon P.M, Du Toit N, Dacre I.T. Equine Dental Pathology.. In: Easley K.J., Dixon P.M., Schu-macher J., editors. Equine Dentistry. 3rd ed. Elsevier Saunders; Edinburgh, UK: 2010. pp. 129–147.
- Jackson K, Kelty E, Meylan M, Tennant M. A randomized controlled trial assessing the effects of feeding high water soluble carbohydrate (WSC) oaten hay versus low WSC oaten hay on equine peripheral dental caries.. J. Equine Vet. Sci. 2021;98:103356.
- Dixon P.M. Equine peripheral and infundibular dental caries: A review and proposals for their investigation.. Equine Vet. Educ. 2017;29:621–628.
- Furtado C.E, Brandi R.A, Ribeiro L.B. Utilização de coprodutos e demais alimentos alternativos para dietas de equinos no Brasil.. Rev. Bras. Zootec. 2011;40:232–241.
- Soames J.V, Southam J.C. Oral Pathology: A Comprehensive Review.. 4th ed. Oxford University Press; Oxford, UK: 2005.
- Barnett T.P. Clinical Insights: Equine Dentistry.. Equine Vet. J. 2019;8:277–279.
- Borkent D, Reardon R.J.M, McLachlan G, Glendinning L, Dixon P.M. Microbiome analysis of equine peripheral dental caries using next generation sequencing.. Equine Vet. J. 2020;52:67–75.
- Bucker B.A. Treatment of equine diastemata. Proceedings of the American Association of Equine Practitioners—AAEP Focus Meeting; Indianapolis, IN, USA. 1 August 2006.
- Hirsh D.C, Zee Y.C. Microbiologia Veterinária.. 5th ed. Guanabara Koogan; Rio de Janeiro, Brazil: 2003. p. 446.
- Braga C.A.S.B, Resende C.M.F, Pestana A.C.N.R, Carmo L.S, Costa J.E, Silva L.A.F, de Assis L.N, de Assis Lima L, Farias L.M, Carvalho M.A.R. Isolamento e identificação da microbiota periodontal de cães da raça Pastor Alemão.. Ciênc. Rural. 2005;35:385–390.
- Quinn P.J, Markey B.K, Carter M.E, Donnelly W.J, Leonard F.C. Microbiologia Veterinária e Doenças Infecciosas.. Artmed; Porto Alegre, Brazil: 2005. pp. 115–130.
- Tortora G.J, Case C.L, Funke B.R. Microbiologia.. 12th ed. Artmed; Porto Alegre, Brazil: 2016.
- Kennedy R, Lappin D.F, Dixon P.M, Buijs M.J, Zaura E, Crielaard W, O’Donnell L, Bennett D, Brandt B.W, Riggio M.P. The microbiome associated with equine periodontitis and oral health.. Vet. Res. 2016;47:49.
- Genro T.C.M, Orqis M.G. Informações Básicas Sobre Coleta de Amostras e Principais Análises Químico-Bromatológicas de Alimentos Destinados à Produção de Ruminantes.. Embrapa Pecuária Sul; Bagé, Brazil: 2008. pp. 10–12.
- Association of Official Agricultural Chemists . Official Methods of Analysis. Volume 12. Association of Official Agricultural Chemists; Washington, DC, USA: 2006. p. 13.
- Hendrix D.L. Rapid extraction and analysis of nonstructural carbohydrates in plant tissues. Crop Sci. 1993;33:1306–1311. doi: 10.2135/cropsci1993.0011183X003300060037x.
- Silva D.J., Queiroz A.C. Análise de Alimentos: Métodos Químicos e Biológicos. 3rd ed. UFV; Viçosa, Brazil: 2006. p. 235.
- Caporaso J.G., Lauber C.L., Walters W.A., Berg-Lyons D., Lozupone C.A., Turnbaugh P.J., Fierer N., Knight R. Global patterns of 16S rRNA diversity at a depth of millions of sequences per sample. Proc. Natl. Acad. Sci. USA. 2011;108((Suppl. S1)):4516–4522. doi: 10.1073/pnas.1000080107.
- Costa M.C., Weese J.C. Understanding the intestinal microbiome in health and disease. Vet. Clin. Equine Pract. 2015;34:1–12. doi: 10.1016/j.cveq.2017.11.005.
- Dacre I.T. Equine dental pathology. In: Baker G.J., Easley K.L., editors. Equine Dentistry. 2nd ed. Elsevier Saunders; Edinburgh, UK: 2005. pp. 91–110.
- Marsh P.D. Role of the oral microflora in health. Microb. Ecol. Health Dis. 2000;12:130–137.
- Baker G.J. Some aspects of equine dental decay. Equine Vet. J. 1974;6:127–130. doi: 10.1111/j.2042-3306.1974.tb03945.x.
- Kilic S., Dixon P.M., Kempson S.A. A light microscopic and ultrastructural examination of calcified dental tissues of horses: 4. Cement and the amelocemental junction. Equine Vet. J. 1997;29:213–219. doi: 10.1111/j.2042-3306.1997.tb01671.x.
- Windley Z., Weller R., Tremaine W.H., Perkins J.D. Two-and three-dimensional computed tomographic anatomy of the enamel, infundibulae and pulp of 126 equine cheek teeth. Part 2: Findings in teeth with macroscopic occlusal or computed tomographic lesions. Equine Vet. J. 2009;41:441–447. doi: 10.2746/042516409X391033.
- Fitzgibbon C.M., du Toit N., Dixon P.M. Anatomical studies of maxillary cheek teeth infundibula in clinically normal horses. Equine Vet. J. 2010;42:37–43. doi: 10.2746/042516409X474761.
- Borkent D., Reardon R.J.M., McLachlan G., Smith S., Dixon P.M. An epidemiological survey on the prevalence of equine peripheral dental caries in the United Kingdom and possible risk factors for its development. Equine Vet. J. 2017;49:480–485. doi: 10.1111/evj.12610.
- Horbal A., Smith S., Dixon P.M. A computed tomographic (CT) and pathological study of equine cheek teeth infundibulae extracted from asymptomatic horses. Part 1: Prevalence, type and location of infundibular lesions on CT imaging. Front Vet. Sci. 2019;6:124. doi: 10.3389/fvets.2019.00124.
- Bor B.J., Bedree J.K., Shi W., McLean J.S., He X. Saccharibacteria (TM7) in the human oral microbiome. J. Dent. Res. 2019;98:500–509. doi: 10.1177/0022034519831671.
- Barbosa N.A. Ph.D. Thesis. Universidade do Estado do Amazonas; Manaus, Brazil: 2019. Análise Metagenômica Da Microbiota Associada à Doença Periodontal.
- Yang F., Zeng X., Ning K., Liu K.L., Lo C.C., Wang W., Chen J., Wang D., Huang R., Chang X., et al. Saliva microbiomes distinguish caries-active from healthy human populations. ISME J. 2012;6:1–10. doi: 10.1038/ismej.2011.71.
- Kleinberg I. A mixed-bacteria ecological approach to understanding the role of oral bacteria in dental caries causation: An alternative to Streptococcus mutans and specific plaque hypothesis. Crit. Rev. Oral. Biol. Med. 2002;13:108–125. doi: 10.1177/154411130201300202.
- Gao W., Chan Y., You M., Lacap-Bugler C.D., Keung L.W., Rory M.W. In-depth snapshot of the equine subgingival microbiome. Microb. Pathog. 2016;94:76–89. doi: 10.1016/j.micpath.2015.11.002.
- Jackson K., Kelty E., Tennant M. Peripheral caries and disease of the periodontium in Western Australian horses: An epidemiological, anatomical and histopathological assessment. Equine Vet. J. 2019;51:617–624. doi: 10.1111/evj.13084.
- Jackson K., Kelty E., Tennant M. Equine peripheral dental caries: An epidemiological survey assessing prevalence and possible risk factors in Western Australian horses. Equine Vet. J. 2018;50:79–84. doi: 10.1111/evj.12718.
- Gere I., Dixon P.M. Post mortem survey of peripheral dental caries in 510 Swedish horses. Equine Vet. J. 2010;42:310–315. doi: 10.1111/j.2042-3306.2009.00024.x.
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
