FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Journal of animal science2018; 95(11); 5077-5090; doi: 10.2527/jas2017.1754

Influence of short-term dietary starch inclusion on the equine cecal microbiome.

Abstract: The objective of this study was to determine bacterial community profiles of the equine cecum in response to abrupt inclusion of varying levels of dietary starch. Seven cecally cannulated Quarter Horse geldings (497 to 580 kg) were used in a crossover design with two 28-d periods and a 28-d washout between each. Horses were randomly assigned to dietary treatments consisting of a commercial concentrate offered as fed at either 0.6 (low starch [LS]) or 1.2% BW (high starch [HS]) daily that was divided into 2 meals at 12-h intervals. Prior to the start of each period, horses were allowed ad libitum access to coastal bermudagrass () hay. Concentrate was fed on d 1 with no adaptation. Cecal fluid was collected on d 1 at h 0 and at 3, 6, 9, and 12 h relative to the initial concentrate meal on d 1. Additional samples were collected 6 h after feeding on d 2, 3, and 7 of each period. Cecal contents were used to determine pH and VFA concentrations and extract microbial DNA. The V4 through V6 region of 16S rRNA gene was amplified using PCR and sequenced on the Roche 454 FLX platform. Sequence analysis was performed with QIIME, and data were analyzed using the MIXED procedure of SAS. Cecal pH tended to decrease ( = 0.09) in horses fed HS in the first 12 h after the first concentrate meal and remained lower ( ≤ 0.05) the following 7 d. Total VFA were greater ( ≤ 0.05) in horses fed HS in the initial 12 h and 7 d after addition of concentrate. Species richness determined using the Chao1 index was unchanged ( > 0.20) over the initial 12 h and decreased ( = 0.01) over 7 d for both treatments. Community diversity determined using the Shannon index tended to decrease ( = 0.06) over the 7 d. Relative abundances of Paraprevotellaceae were greater ( ≤ 0.05) in HS in the first 12 h. Over 7 d, relative abundances of Paraprevotellaceae, Veillonellaceae, and Succinivibrionaceae were greater ( ≤ 0.05) in HS compared with LS. Abrupt and short-term exposure to dietary starch does alter cecal fermentation and microbial community structure in horses, but the impact on horse health is unknown.
Get Full Text
Publication Date: 2018-01-03 PubMed ID: 29293739PubMed Central: PMC6095290DOI: 10.2527/jas2017.1754Google 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.
LinkedInCopy
  • 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.

This study investigated how sudden changes to dietary starch levels alter the bacterial community in the cecum of horses. Using seven Quarter Horse geldings, the study found that an abrupt influx of dietary starch shifts microbial fermentation and modifies the cecal microbiome composition.

Methods and Experimental Design

The research involved seven Quarter Horse geldings all fitted with cecal cannulas. The horses alternated between two diet regimes in a crossover design. These involved a 28-day period of low starch (LS) and high starch (HS) diets with a 28-day washout phase in between each cycle.

  • The LS diet comprised of a commercial feed comprising 0.6% bodyweight of starch fed in two meals per day.
  • The HS diet consisted of the same commercial feed but at 1.2% bodyweight of starch in two meals each day.
  • Before each diet cycle, the horses had unrestricted access to coastal bermudagrass hay.

At specific intervals over seven days, researchers collected cecal fluid samples to analyze the changes in the bacterial communities.

Findings

The researchers used polymerase chain reaction (PCR) to amplify the 16S rRNA gene regions in microbial DNA from the fluid samples. They then sequenced the genes and analyzed the sequences with Quantitative Insights Into Microbial Ecology (QIIME) software. This analysis led to the following findings:

  • There was a tendency for the cecal pH to drop in the HS-fed horses within the first 12 hours of feeding. This lower pH remained constant for 7 days.
  • Researchers noted higher total VFA (volatile fatty acids) concentrations initially and over seven days in horses on the HS diet.
  • Species richness, indicated using the Chao1 index, remained unchanged within the first 12 hours but registered a decrease over the 7-day period for both diet groups.
  • The study observed a significant increase in the abundance of certain bacteria, such as Paraprevotellaceae, Veillonellaceae, and Succinivibrionaceae in horses on the HS diet.

Conclusion

The study concluded that the abrupt introduction of dietary starch can transform the microbial fermentation and the structure of the cecal bacterial community in horses. However, the potential effects that these changes may have on the health of the horse remain unclear.

Cite This Article

APA
Warzecha CM, Coverdale JA, Janecka JE, Leatherwood JL, Pinchak WE, Wickersham TA, McCann JC. (2018). Influence of short-term dietary starch inclusion on the equine cecal microbiome. J Anim Sci, 95(11), 5077-5090. https://doi.org/10.2527/jas2017.1754

Publication

Journal of animal science
ISSN: 1525-3163
NlmUniqueID: 8003002
Country: United States
Language: English
Volume: 95
Issue: 11
Pages: 5077-5090

Researcher Affiliations

Warzecha, C M
    Coverdale, J A
      Janecka, J E
        Leatherwood, J L
          Pinchak, W E
            Wickersham, T A
              McCann, J C

                MeSH Terms

                • Animal Feed / analysis
                • Animals
                • Bacteria / classification
                • Bacteria / genetics
                • Cecum / microbiology
                • Diet / veterinary
                • Dietary Carbohydrates / administration & dosage
                • Digestion
                • Fatty Acids, Volatile / metabolism
                • Fermentation
                • Horses / physiology
                • Hydrogen-Ion Concentration
                • Male
                • Microbiota
                • Starch / administration & dosage

                References

                This article includes 51 references
                1. Al Jassim RA, Scott PT, Trebbin AL, Trott D, Pollitt CC. The genetic diversity of lactic acid producing bacteria in the equine gastrointestinal tract.. FEMS Microbiol Lett 2005 Jul 1;248(1):75-81.
                  pubmed: 15953698doi: 10.1016/j.femsle.2005.05.023google scholar: lookup
                2. Argenzio RA, Southworth M, Stevens CE. Sites of organic acid production and absorption in the equine gastrointestinal tract.. Am J Physiol 1974 May;226(5):1043-50.
                  pubmed: 4824856doi: 10.1152/ajplegacy.1974.226.5.1043google scholar: lookup
                3. Bergey D, Buchanan RE, Gibbons NE. Bergey’s manual of determinative bacteriology. .
                4. Bervoets L, Van Hoorenbeeck K, Kortleven I, Van Noten C, Hens N, Vael C, Goossens H, Desager KN, Vankerckhoven V. Differences in gut microbiota composition between obese and lean children: a cross-sectional study.. Gut Pathog 2013 Apr 30;5(1):10.
                  pmc: PMC3658928pubmed: 23631345doi: 10.1186/1757-4749-5-10google scholar: lookup
                5. Beals EW. Bray-Curtis ordination: An effective strategy for analysis of multivariate ecological data. Adv. Ecol. Res. 14: 1–55.
                  doi: 10.1016/s0065-2504(08)60168-3google scholar: lookup
                6. Biddle AS, Black SJ, Blanchard JL. An in vitro model of the horse gut microbiome enables identification of lactate-utilizing bacteria that differentially respond to starch induction.. PLoS One 2013;8(10):e77599.
                  pmc: PMC3788102pubmed: 24098591doi: 10.1371/journal.pone.0077599google scholar: lookup
                7. Callaway TR, Dowd SE, Edrington TS, Anderson RC, Krueger N, Bauer N, Kononoff PJ, Nisbet DJ. Evaluation of bacterial diversity in the rumen and feces of cattle fed different levels of dried distillers grains plus solubles using bacterial tag-encoded FLX amplicon pyrosequencing.. J Anim Sci 2010 Dec;88(12):3977-83.
                  pubmed: 20729286doi: 10.2527/jas.2010-2900google scholar: lookup
                8. Caporaso JG, Bittinger K, Bushman FD, DeSantis TZ, Andersen GL, Knight R. PyNAST: a flexible tool for aligning sequences to a template alignment.. Bioinformatics 2010 Jan 15;26(2):266-7.
                  pmc: PMC2804299pubmed: 19914921doi: 10.1093/bioinformatics/btp636google scholar: lookup
                9. Caporaso JG, Kuczynski J, Stombaugh J, Bittinger K, Bushman FD, Costello EK, Fierer N, Peña AG, Goodrich JK, Gordon JI, Huttley GA, Kelley ST, Knights D, Koenig JE, Ley RE, Lozupone CA, McDonald D, Muegge BD, Pirrung M, Reeder J, Sevinsky JR, Turnbaugh PJ, Walters WA, Widmann J, Yatsunenko T, Zaneveld J, Knight R. QIIME allows analysis of high-throughput community sequencing data.. Nat Methods 2010 May;7(5):335-6.
                  pmc: PMC3156573pubmed: 20383131doi: 10.1038/nmeth.f.303google scholar: lookup
                10. Chen Y, Penner GB, Li M, Oba M, Guan LL. Changes in bacterial diversity associated with epithelial tissue in the beef cow rumen during the transition to a high-grain diet.. Appl Environ Microbiol 2011 Aug 15;77(16):5770-81.
                  pmc: PMC3165274pubmed: 21705529doi: 10.1128/aem.00375-11google scholar: lookup
                11. Clarke KR, Gorley RN. PRIMER v6: User manual PRIMER-E. Plymouth. 192 pp. Plymouth, UK.
                12. Costa MC, Arroyo LG, Allen-Vercoe E, Stämpfli HR, Kim PT, Sturgeon A, Weese JS. Comparison of the fecal microbiota of healthy horses and horses with colitis by high throughput sequencing of the V3-V5 region of the 16S rRNA gene.. PLoS One 2012;7(7):e41484.
                  pmc: PMC3409227pubmed: 22859989doi: 10.1371/journal.pone.0041484google scholar: lookup
                13. Costa MC, Silva G, Ramos RV, Staempfli HR, Arroyo LG, Kim P, Weese JS. Characterization and comparison of the bacterial microbiota in different gastrointestinal tract compartments in horses.. Vet J 2015 Jul;205(1):74-80.
                  pubmed: 25975855doi: 10.1016/j.tvjl.2015.03.018google scholar: lookup
                14. Coverdale JA, Tyler HD, Quigley JD 3rd, Brumm JA. Effect of various levels of forage and form of diet on rumen development and growth in calves.. J Dairy Sci 2004 Aug;87(8):2554-62.
                  pubmed: 15328279doi: 10.3168/jds.s0022-0302(04)73380-9google scholar: lookup
                15. Daly K, Stewart CS, Flint HJ, Shirazi SP-Beechey. Bacterial diversity within the equine large intestine as revealed by molecular analysis of cloned 16S rRNA genes. FEMS Microbiol. Ecol. 38: 141–151.
                  doi: 10.1111/j.1574-6941.2001.tb00892.xgoogle scholar: lookup
                16. de Fombelle A, Julliand V, C Drogoul, E Jacotot. Feeding and microbial disorders in horses: 1-Effects of an abrupt incorporation of two levels of barley in a hay diet on microbial profile and activities. J. Equine Vet. Sci. 21: 439–445.
                  doi: 10.1016/s0737-0806(01)70018-4google scholar: lookup
                17. Dougal K, Harris PA, Edwards A, Pachebat JA, Blackmore TM, Worgan HJ, Newbold CJ. A comparison of the microbiome and the metabolome of different regions of the equine hindgut.. FEMS Microbiol Ecol 2012 Dec;82(3):642-52.
                  pubmed: 22757649doi: 10.1111/j.1574-6941.2012.01441.xgoogle scholar: lookup
                18. Dowd SE, Sun Y, Wolcott RD, Domingo A, Carroll JA. Bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP) for microbiome studies: bacterial diversity in the ileum of newly weaned Salmonella-infected pigs.. Foodborne Pathog Dis 2008 Aug;5(4):459-72.
                  pubmed: 18713063doi: 10.1089/fpd.2008.0107google scholar: lookup
                19. Edgar RC, Haas BJ, Clemente JC, Quince C, Knight R. UCHIME improves sensitivity and speed of chimera detection.. Bioinformatics 2011 Aug 15;27(16):2194-200.
                  pmc: PMC3150044pubmed: 21700674doi: 10.1093/bioinformatics/btr381google scholar: lookup
                20. Fernando SC, Purvis HT 2nd, Najar FZ, Sukharnikov LO, Krehbiel CR, Nagaraja TG, Roe BA, Desilva U. Rumen microbial population dynamics during adaptation to a high-grain diet.. Appl Environ Microbiol 2010 Nov;76(22):7482-90.
                  pmc: PMC2976194pubmed: 20851965doi: 10.1128/aem.00388-10google scholar: lookup
                21. Hansen NC, Avershina E, Mydland LT, Næsset JA, Austbø D, Moen B, Måge I, Rudi K. High nutrient availability reduces the diversity and stability of the equine caecal microbiota.. Microb Ecol Health Dis 2015;26:27216.
                  pmc: PMC4526772pubmed: 26246403doi: 10.3402/mehd.v26.27216google scholar: lookup
                22. Hartstra AV, Bouter KE, Bäckhed F, Nieuwdorp M. Insights into the role of the microbiome in obesity and type 2 diabetes.. Diabetes Care 2015 Jan;38(1):159-65.
                  pubmed: 25538312doi: 10.2337/dc14-0769google scholar: lookup
                23. Hintz HF, Argenzio RA, Schryver HF. Digestion coefficients, blood glucose levels and molar percentage of volatile acids in intestinal fluid of ponies fed varying forage-grain ratios.. J Anim Sci 1971 Nov;33(5):992-5.
                  pubmed: 5119977doi: 10.2527/jas1971.335992xgoogle scholar: lookup
                24. Jami E, Israel A, Kotser A, Mizrahi I. Exploring the bovine rumen bacterial community from birth to adulthood.. ISME J 2013 Jun;7(6):1069-79.
                  pmc: PMC3660679pubmed: 23426008doi: 10.1038/ismej.2013.2google scholar: lookup
                25. Jami E, Mizrahi I. Composition and similarity of bovine rumen microbiota across individual animals.. PLoS One 2012;7(3):e33306.
                  pmc: PMC3303817pubmed: 22432013doi: 10.1371/journal.pone.0033306google scholar: lookup
                26. Julliand V, de Fombelle A, Drogoul C, E Jacotot. Feeding and microbial disorders in horses: 3 - Effects of three hay: Grain ratios on microbial profile and activities. J. Equine Vet. Sci. 21: 543–546.
                  doi: 10.1016/s0737-0806(01)70159-1google scholar: lookup
                27. Leek BF. Digestion in the ruminant stomach. In: Swenson M. J., editor, Dukes’ physiology of domestic animals. Comstock Publ. Assoc., Ithaca, NY. p. 438-474.
                28. Lehman CL, Tilman D. Biodiversity, Stability, and Productivity in Competitive Communities.. Am Nat 2000 Nov;156(5):534-552.
                  pubmed: 29587515doi: 10.1086/303402google scholar: lookup
                29. Li M, Zhou M, Adamowicz E, Basarab JA, Guan LL. Characterization of bovine ruminal epithelial bacterial communities using 16S rRNA sequencing, PCR-DGGE, and qRT-PCR analysis.. Vet Microbiol 2012 Feb 24;155(1):72-80.
                  pubmed: 21890283doi: 10.1016/j.vetmic.2011.08.007google scholar: lookup
                30. Lin C, Stahl DA. Taxon-specific probes for the cellulolytic genus Fibrobacter reveal abundant and novel equine-associated populations.. Appl Environ Microbiol 1995 Apr;61(4):1348-51.
                  pmc: PMC167390pubmed: 7538274doi: 10.1128/aem.61.4.1348-1351.1995google scholar: lookup
                31. Malmuthuge N, Griebel PJ, Guan le L. Taxonomic identification of commensal bacteria associated with the mucosa and digesta throughout the gastrointestinal tracts of preweaned calves.. Appl Environ Microbiol 2014 Mar;80(6):2021-8.
                  pmc: PMC3957634pubmed: 24441166doi: 10.1128/aem.03864-13google scholar: lookup
                32. Mao SY, Zhang RY, Wang DS, Zhu WY. Impact of subacute ruminal acidosis (SARA) adaptation on rumen microbiota in dairy cattle using pyrosequencing.. Anaerobe 2013 Dec;24:12-9.
                  pubmed: 23994204doi: 10.1016/j.anaerobe.2013.08.003google scholar: lookup
                33. McCann JC, Drewery ML, Sawyer JE, Pinchak WE, Wickersham TA. Effect of postextraction algal residue supplementation on the ruminal microbiome of steers consuming low-quality forage.. J Anim Sci 2014 Nov;92(11):5063-75.
                  pubmed: 25349354doi: 10.2527/jas.2014-7811google scholar: lookup
                34. McCann JC, Wiley LM, Forbes TD, Rouquette FM Jr, Tedeschi LO. Relationship between the rumen microbiome and residual feed intake-efficiency of Brahman bulls stocked on bermudagrass pastures.. PLoS One 2014;9(3):e91864.
                  pmc: PMC3958397pubmed: 24642871doi: 10.1371/journal.pone.0091864google scholar: lookup
                35. McDonald D, Price MN, Goodrich J, Nawrocki EP, DeSantis TZ, Probst A, Andersen GL, Knight R, Hugenholtz P. An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea.. ISME J 2012 Mar;6(3):610-8.
                  pmc: PMC3280142pubmed: 22134646doi: 10.1038/ismej.2011.139google scholar: lookup
                36. Meale SJ, Li S, Azevedo P, Derakhshani H, Plaizier JC, Khafipour E, Steele MA. Development of Ruminal and Fecal Microbiomes Are Affected by Weaning But Not Weaning Strategy in Dairy Calves.. Front Microbiol 2016;7:582.
                  pmc: PMC4853645pubmed: 27199916doi: 10.3389/fmicb.2016.00582google scholar: lookup
                37. Milinovich GJ, Klieve AV, Pollitt CC, Trott DJ. Microbial events in the hindgut during carbohydrate-induced equine laminitis.. Vet Clin North Am Equine Pract 2010 Apr;26(1):79-94.
                  pubmed: 20381737doi: 10.1016/j.cveq.2010.01.007google scholar: lookup
                38. Moreau MM, Eades SC, Reinemeyer CR, Fugaro MN, Onishi JC. Illumina sequencing of the V4 hypervariable region 16S rRNA gene reveals extensive changes in bacterial communities in the cecum following carbohydrate oral infusion and development of early-stage acute laminitis in the horse.. Vet Microbiol 2014 Jan 31;168(2-4):436-41.
                  pubmed: 24355533doi: 10.1016/j.vetmic.2013.11.017google scholar: lookup
                39. Naushad S, Adeolu M, Goel N, Khadka B, Al-Dahwi A, Gupta RS. Phylogenomic and molecular demarcation of the core members of the polyphyletic pasteurellaceae genera actinobacillus, haemophilus, and pasteurella.. Int J Genomics 2015;2015:198560.
                  pmc: PMC4363679pubmed: 25821780doi: 10.1155/2015/198560google scholar: lookup
                40. Paster BJ, Canale-Parola E. Physiological diversity of rumen spirochetes.. Appl Environ Microbiol 1982 Mar;43(3):686-93.
                  pmc: PMC241895pubmed: 7073277doi: 10.1128/aem.43.3.686-693.1982google scholar: lookup
                41. Petri RM, Schwaiger T, Penner GB, Beauchemin KA, Forster RJ, McKinnon JJ, McAllister TA. Characterization of the core rumen microbiome in cattle during transition from forage to concentrate as well as during and after an acidotic challenge.. PLoS One 2013;8(12):e83424.
                  doi: 10.1371/journal.pone.0083424pmc: PMC3877040pubmed: 24391765google scholar: lookup
                42. Pitta DW, Pinchak E, Dowd SE, Osterstock J, Gontcharova V, Youn E, Dorton K, Yoon I, Min BR, Fulford JD, Wickersham TA, Malinowski DP. Rumen bacterial diversity dynamics associated with changing from bermudagrass hay to grazed winter wheat diets.. Microb Ecol 2010 Apr;59(3):511-22.
                  pubmed: 20037795doi: 10.1007/s00248-009-9609-6google scholar: lookup
                43. Pitta DW, Pinchak WE, Indugu N, Vecchiarelli B, Sinha R, Fulford JD. Metagenomic Analysis of the Rumen Microbiome of Steers with Wheat-Induced Frothy Bloat.. Front Microbiol 2016;7:689.
                  pmc: PMC4863135pubmed: 27242715doi: 10.3389/fmicb.2016.00689google scholar: lookup
                44. Respondek F, Goachet AG, Julliand V. Effects of dietary short-chain fructooligosaccharides on the intestinal microflora of horses subjected to a sudden change in diet.. J Anim Sci 2008 Feb;86(2):316-23.
                  pubmed: 17940163doi: 10.2527/jas.2006-782google scholar: lookup
                45. Shepherd ML, Swecker WS Jr, Jensen RV, Ponder MA. Characterization of the fecal bacteria communities of forage-fed horses by pyrosequencing of 16S rRNA V4 gene amplicons.. FEMS Microbiol Lett 2012 Jan;326(1):62-8.
                  pubmed: 22092776doi: 10.1111/j.1574-6968.2011.02434.xgoogle scholar: lookup
                46. Steelman SM, Chowdhary BP, Dowd S, Suchodolski J, Janečka JE. Pyrosequencing of 16S rRNA genes in fecal samples reveals high diversity of hindgut microflora in horses and potential links to chronic laminitis.. BMC Vet Res 2012 Nov 27;8:231.
                  pmc: PMC3538718pubmed: 23186268doi: 10.1186/1746-6148-8-231google scholar: lookup
                47. Strobel HJ. Vitamin B12-dependent propionate production by the ruminal bacterium Prevotella ruminicola 23.. Appl Environ Microbiol 1992 Jul;58(7):2331-3.
                  pmc: PMC195777pubmed: 1637169doi: 10.1128/aem.58.7.2331-2333.1992google scholar: lookup
                48. Vanzant ES, Cochran RC. Performance and forage utilization by beef cattle receiving increasing amounts of alfalfa hay as a supplement to low-quality, tallgrass-prairie forage.. J Anim Sci 1994 Apr;72(4):1059-67.
                  pubmed: 8014141doi: 10.2527/1994.7241059xgoogle scholar: lookup
                49. Weese JS, Holcombe SJ, Embertson RM, Kurtz KA, Roessner HA, Jalali M, Wismer SE. Changes in the faecal microbiota of mares precede the development of post partum colic.. Equine Vet J 2015 Nov;47(6):641-9.
                  pubmed: 25257320doi: 10.1111/evj.12361google scholar: lookup
                50. Willard JG, Willard JC, Wolfram SA, Baker JP. Effect of diet on cecal pH and feeding behavior of horses.. J Anim Sci 1977 Jul;45(1):87-93.
                  pubmed: 18431doi: 10.2527/jas1977.45187xgoogle scholar: lookup
                51. Wilson KL. The effect of graded levels of dietary starch. MS Thesis, Texas A&M University, College Station, TX.

                Citations

                This article has been cited 24 times.
                1. 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 Feb 22;13(5).
                  doi: 10.3390/ani13050790pubmed: 36899650google scholar: lookup
                2. Wunderlich G, Bull M, Ross T, Rose M, Chapman B. Understanding the microbial fibre degrading communities & processes in the equine gut. Anim Microbiome 2023 Jan 12;5(1):3.
                  doi: 10.1186/s42523-022-00224-6pubmed: 36635784google scholar: lookup
                3. Bustamante CC, de Paula VB, Rabelo IP, Fernandes CC, Kishi LT, Canola PA, Lemos EGM, Valadão CAA. Effects of Starch Overload and Cecal Buffering on Fecal Microbiota of Horses. Animals (Basel) 2022 Dec 6;12(23).
                  doi: 10.3390/ani12233435pubmed: 36496956google scholar: lookup
                4. Collinet A, Grimm P, Jacotot E, Julliand V. Biomarkers for monitoring the equine large intestinal inflammatory response to stress-induced dysbiosis and probiotic supplementation. J Anim Sci 2022 Oct 1;100(10).
                  doi: 10.1093/jas/skac268pubmed: 35980768google scholar: lookup
                5. Weinert-Nelson JR, Biddle AS, Williams CA. Fecal microbiome of horses transitioning between warm-season and cool-season grass pasture within integrated rotational grazing systems. Anim Microbiome 2022 Jun 21;4(1):41.
                  doi: 10.1186/s42523-022-00192-xpubmed: 35729677google scholar: lookup
                6. Lara F, Castro R, Thomson P. Changes in the gut microbiome and colic in horses: Are they causes or consequences?. Open Vet J 2022 Mar-Apr;12(2):242-249.
                  doi: 10.5455/OVJ.2022.v12.i2.12pubmed: 35603065google scholar: lookup
                7. Aleman M, Sheldon SA, Jospin G, Coil D, Stratton-Phelps M, Eisen J. Caecal microbiota in horses with trigeminal-mediated headshaking. Vet Med Sci 2022 May;8(3):1049-1055.
                  doi: 10.1002/vms3.735pubmed: 35060350google scholar: lookup
                8. Fernandes KA, Rogers CW, Gee EK, Kittelmann S, Bolwell CF, Bermingham EN, Biggs PJ, Thomas DG. Resilience of Faecal Microbiota in Stabled Thoroughbred Horses Following Abrupt Dietary Transition between Freshly Cut Pasture and Three Forage-Based Diets. Animals (Basel) 2021 Sep 6;11(9).
                  doi: 10.3390/ani11092611pubmed: 34573577google scholar: lookup
                9. Spurgin CL, Coverdale JA, Leatherwood JL, Redmon LA, Bradbery AN, Wickersham TA. Effects of crude protein content on intake and digestion of coastal bermudagrass hay by horses. Transl Anim Sci 2021 Jul;5(3):txab073.
                  doi: 10.1093/tas/txab073pubmed: 34430798google scholar: lookup
                10. Arnold CE, Pilla R, Chaffin MK, Leatherwood JL, Wickersham TA, Callaway TR, Lawhon SD, Lidbury JA, Steiner JM, Suchodolski JS. The effects of signalment, diet, geographic location, season, and colitis associated with antimicrobial use or Salmonella infection on the fecal microbiome of horses. J Vet Intern Med 2021 Sep;35(5):2437-2448.
                  doi: 10.1111/jvim.16206pubmed: 34268795google scholar: lookup
                11. Theelen MJP, Luiken REC, Wagenaar JA, Sloet van Oldruitenborgh-Oosterbaan MM, Rossen JWA, Zomer AL. The Equine Faecal Microbiota of Healthy Horses and Ponies in The Netherlands: Impact of Host and Environmental Factors. Animals (Basel) 2021 Jun 12;11(6).
                  doi: 10.3390/ani11061762pubmed: 34204691google scholar: lookup
                12. Collinet A, Grimm P, Julliand S, Julliand V. Sequential Modulation of the Equine Fecal Microbiota and Fibrolytic Capacity Following Two Consecutive Abrupt Dietary Changes and Bacterial Supplementation. Animals (Basel) 2021 Apr 29;11(5).
                  doi: 10.3390/ani11051278pubmed: 33946811google scholar: lookup
                13. Sorensen RJ, Drouillard JS, Douthit TL, Ran Q, Marthaler DG, Kang Q, Vahl CI, Lattimer JM. Effect of hay type on cecal and fecal microbiome and fermentation parameters in horses. J Anim Sci 2021 Jan 1;99(1).
                  doi: 10.1093/jas/skaa407pubmed: 33515482google scholar: lookup
                14. Kauter A, Epping L, Semmler T, Antao EM, Kannapin D, Stoeckle SD, Gehlen H, Lübke-Becker A, Günther S, Wieler LH, Walther B. The gut microbiome of horses: current research on equine enteral microbiota and future perspectives. Anim Microbiome 2019 Nov 13;1(1):14.
                  doi: 10.1186/s42523-019-0013-3pubmed: 33499951google scholar: lookup
                15. Górniak W, Cholewińska P, Szeligowska N, Wołoszyńska M, Soroko M, Czyż K. Effect of Intense Exercise on the Level of Bacteroidetes and Firmicutes Phyla in the Digestive System of Thoroughbred Racehorses. Animals (Basel) 2021 Jan 24;11(2).
                  doi: 10.3390/ani11020290pubmed: 33498857google scholar: lookup
                16. Arnold CE, Isaiah A, Pilla R, Lidbury J, Coverdale JS, Callaway TR, Lawhon SD, Steiner J, Suchodolski JS. The cecal and fecal microbiomes and metabolomes of horses before and after metronidazole administration. PLoS One 2020;15(5):e0232905.
                  doi: 10.1371/journal.pone.0232905pubmed: 32442163google scholar: lookup
                17. Morrison PK, Newbold CJ, Jones E, Worgan HJ, Grove-White DH, Dugdale AH, Barfoot C, Harris PA, Argo CM. Effect of age and the individual on the gastrointestinal bacteriome of ponies fed a high-starch diet. PLoS One 2020;15(5):e0232689.
                  doi: 10.1371/journal.pone.0232689pubmed: 32384105google scholar: lookup
                18. Peachey LE, Castro C, Molena RA, Jenkins TP, Griffin JL, Cantacessi C. Dysbiosis associated with acute helminth infections in herbivorous youngstock - observations and implications. Sci Rep 2019 Jul 31;9(1):11121.
                  doi: 10.1038/s41598-019-47204-6pubmed: 31366962google scholar: lookup
                19. De La Torre U, Henderson JD, Furtado KL, Pedroja M, Elenamarie O, Mora A, Pechanec MY, Maga EA, Mienaltowski MJ. Utilizing the fecal microbiota to understand foal gut transitions from birth to weaning. PLoS One 2019;14(4):e0216211.
                  doi: 10.1371/journal.pone.0216211pubmed: 31039168google scholar: lookup
                20. Franzan BC, da Silva Coelho I, Ramos EM, de Souza ARP, de Almeida FQ, Silva VP. Complete Extruded Diet: How Does Equine Fecal Microbiota Change During Intake Adaptation?. Anim Sci J 2026 Jan-Dec;97(1):e70147.
                  doi: 10.1111/asj.70147pubmed: 41504615google scholar: lookup
                21. Zhang W, Guo R, Sulayman A, Sun Y, Liu S. Research Progress on Influencing Factors of Gastrointestinal Microbial Diversity in Equine. Vet Med Sci 2025 May;11(3):e70271.
                  doi: 10.1002/vms3.70271pubmed: 40145999google scholar: lookup
                22. Carter MM, Leatherwood JL, Paris BL, Moore GE, George JM, Martinez RE, Karges K, Cox JR, Arnold CE, Glass KG, Bradbery AN, Rodiles A, Wickersham TA. Influence of Saccharomyces cerevisiae CNCM I-1077 on the fecal pH, markers of gut permeability, fecal microbiota, and markers of systemic inflammation in sedentary horses fed a high-starch diet. J Anim Sci 2025 Jan 4;103.
                  doi: 10.1093/jas/skaf005pubmed: 39803897google scholar: lookup
                23. Brandi LA, Nunes AT, Faleiros CA, Poleti MD, Oliveira ECM, Schmidt NT, Sousa RLM, Fukumasu H, Balieiro JCC, Brandi RA. Dietary Energy Sources Affect Cecal and Fecal Microbiota of Healthy Horses. Animals (Basel) 2024 Dec 3;14(23).
                  doi: 10.3390/ani14233494pubmed: 39682460google scholar: lookup
                24. Boucher L, Leduc L, Leclère M, Costa MC. Current Understanding of Equine Gut Dysbiosis and Microbiota Manipulation Techniques: Comparison with Current Knowledge in Other Species. Animals (Basel) 2024 Feb 28;14(5).
                  doi: 10.3390/ani14050758pubmed: 38473143google scholar: lookup
                Subscribe to our newsletter
                Join 99,928 horse owners like you who receive our email updates on horse health and nutrition.