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Animals : an open access journal from MDPI2025; 15(17); 2547; doi: 10.3390/ani15172547

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.
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Publication Date: 2025-08-29 PubMed ID: 40941342PubMed Central: PMC12427182DOI: 10.3390/ani15172547Google 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.

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.

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

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 15
Issue: 17
PII: 2547

Researcher Affiliations

Lacerenza, Milena Domingues
  • Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
Arantes, Júlia de Assis
  • Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
Reginato, Gustavo Morandini
  • Department of Veterinary Medicine, School of Animal Science and Food Engineering, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
Finardi, Gabriela Luiza Fagundes
  • 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.
Marchi, Pedro Henrique
  • 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.
Vendramini, Thiago Henrique Annibale
  • 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.
Corrêa, Rodrigo Romero
  • Teaching and Research Support Center (CAEP), School of Veterinary Medicine and Animal Science, University of Sao Paulo, Pirassununga 13635-900, SP, Brazil.
Pereira, Pamela Aparecida Maldaner
  • Faculty of Agricultural and Veterinary Sciences, Sao Paulo State University, Jaboticabal 14884-900, SP, Brazil.
Valadão, Carlos Augusto Araújo
  • Faculty of Agricultural and Veterinary Sciences, Sao Paulo State University, Jaboticabal 14884-900, SP, Brazil.
Dória, Renata Gebara Sampaio
  • 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.

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