The equine microbiome refers to the diverse community of microorganisms, including bacteria, fungi, and viruses, residing in various parts of a horse's body, such as the gastrointestinal tract, skin, and respiratory system. These microorganisms are involved in numerous physiological processes, including digestion, metabolism, and immune function. The composition and diversity of the microbiome can be influenced by factors such as diet, environment, and health status. Research in this area explores the characterization of the equine microbiome, its impact on health and disease, and potential applications in managing equine health. This page compiles peer-reviewed research studies and scholarly articles that investigate the composition, function, and implications of the microbiome in horses.
Arantes JA, Di Pietro R, Ratté M, Arroyo LG, Leclère M, Costa MC.Fecal microbiota transplantation (FMT) has been used as a treatment option for horses (Equus caballus) with gastrointestinal diseases. Several preparation and conservation protocols to improve bacterial survival have been studied in other species. Unassigned: This study aimed to evaluate the impact of oxygen exposure and different protectant solutions on bacterial viability before and after freezing using horse feces. Fecal samples from 10 healthy horses were aliquoted and diluted in cryoprotectant solutions containing antioxidants (n = 40) or 10% glycerol (n = 40). Half of the aliquots from e...
Płoneczka-Janeczko K, Armstrong E, Siemieniuch-Tartanus M, Magdziarz M.The aim of the study was to explore and characterise healthy foals' eye microbiomes in the first two months of life. Unassigned: Conjunctival swabs were collected three times, not later than 12 h after delivery and again at the end of the first and the second months of life from six clinically healthy foals of the Polish Konik breed. The average interval between the first and second samplings was 33.3 days and between the second and third was 35.6 days. Next-generation sequencing performed on a MiSeq sequencer in paired-end technology was used to analyse the composition of the conjunctival mic...
François AC, Cesarini C, Taminiau B, Renaud B, Kruse CJ, Boemer F, van Loon G, Palmers K, Daube G, Wouters CP, Lecoq L, Gustin P, Votion DM.Hypoglycin A and methylenecyclopropylglycine are protoxins responsible for atypical myopathy in equids. These protoxins are converted into toxins that inhibit fatty acid β-oxidation, leading to blood accumulation of acylcarnitines and toxin conjugates, such as methylenecyclopropylacetyl-carnitine. The enzymes involved in this activation are also present in some prokaryotic cells, raising questions about the potential role of intestinal microbiota in the development of intoxication. Differences have been noted between the faecal microbiota of cograzers and atypical myopathy-affected horses. Ho...
Holley L, Creasey HN, Bedenice D, Reed S, Romualdo da Silva DR, Trautwein V, Mazan M, Widmer G.Glucocorticosteroids remain the most common pharmaceutical approach for the treatment of equine asthma but can be associated with significant side effects, including respiratory microbiome alterations. The goal of the study was to assess the impact of 2% lidocaine nebulization, a projected alternative treatment of equine asthma, on the healthy equine respiratory microbiota. A prospective, randomized, controlled, blinded, 2-way crossover study was performed, to assess the effect of 1 mg/kg 2% lidocaine (7 treatments over 4 days) on the equine respiratory microbiota compared to control horses (s...
Wang W, Gibson J, Horsman S, Mikkelsen D, Bertin FR.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 decrea...
Marsella R.Information on skin barrier in horses is limited. A study on the epidermal ultrastructure of normal and allergic horses documented disorganized amorphous intercellular lipids in the stratum corneum of allergic samples. These findings are similar to atopic canine and human skin. Currently, there is no published study comparing skin barrier function parameters between normal and allergic horses; thus, the functional implications of the ultrastructural changes are unknown. In normal horses, body location, gender, breed, and ambient conditions affect skin barrier parameters, such as Transepidermal...
Shi Y, Maga EA, Mienaltowski MJ.Diarrhea is a common disease that could threaten the welfare of newborn foals. While there are several forms of foal diarrhea, the etiologies can be considered known pathogenic or non-pathogenic in nature. Moreover, there are likely differences in the composition of microbial populations in the gastrointestinal tracts of foals depending upon the etiology of diarrhea. Our study aims to examine the microbial population in the feces of foals with both pathogenic and non-pathogenic diarrheas to discern differences in their microbial compositions. Results: Foal diarrhea samples tested positive or n...
Jarquín-Díaz VH, Dayaram A, Soilemetzidou ES, Desvars-Larrive A, Bohner J, Buuveibaatar B, Kaczensky P, Walzer C, Greenwood AD, Löber U.The microbial composition of host-associated microbiomes is influenced by co-evolutionary interactions, host genetics, domestication, and the environment. This study investigates the contribution of environmental microbiota from freshwater bodies to the gastrointestinal microbiomes of wild khulans (Equus hemionus hemionus, n = 21) and compares them with those of captive khulans (n = 12) and other equids-Przewalski's horse (n = 82) and domestic horse (n = 26). Using PacBio technology and the LotuS pipeline for 16S rRNA gene sequencing, we analyze microbial diversity and conduct ...
Żak-Bochenek A, Żebrowska-Różańska P, Bajzert J, Łaczmański Ł, Szponar B, Siwińska N, Gładysz K, Sikorska K, Chełmońska-Soyta A.Oral probiotic dietary supplements are widely used in veterinary medicine, including in horses. It is hypothesized that the presence of probiotic strains can both modulate the intestinal microbiota and affect mucosal immunity parameters. Such a study has not yet been conducted in horses. Unassigned: This study involved 12 healthy horses, which were randomly divided into a control group and a group that received a commercial oral probiotic formula containing , or for 84 days. Fecal samples were collected from all horses on day 0 (D0), 28 days after starting the probiotic (D28), 56 days (D56),...
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.Thirty mature Quarter Horse geldings were used in a completely randomized 32-d study to test the hypotheses that supplemental live Saccharomyces cerevisiae CNCM I-1077 improves apparent digestion, stabilizes the fecal pH, reduces gut permeability, maintains microbial communities, and decreases inflammation in horses fed a high-starch diet. Horses were stratified by body weight, age, and body condition score (BCS) to one of two treatments: concentrate formulated with 2g starch • kg BW-1 • meal-1 (CON; n=15) or the same concentrate top-dressed with 25g/d Saccharomyces cerevisiae CNCM I-1077 ...
Styková E, Valocký I, Kačírová J, Fecskeová LK.Equine pastern dermatitis (EPD) is a multifactorial disease with a change in the skin microbiome. The present study monitored the influence of Weissella cibaria Biocenol™ 4/8 D37 CCM 9015 stabilized on alginite on the skin microbiota of healthy horses and model patients with EPD. Based on clinical signs, EPD lesions were identified as exudative or proliferative forms. A comparison of the initial microbial community based on 16S rRNA amplicon sequencing revealed that there was a statistically significant difference between healthy vs. exudative (R = 0.52, p = 0.003) and exudative vs. ...
Bernabe MCM, Fonseca BB, Silva MVC, Pedrosa IE, Silva MB, Sommerfeld S, de Sousa ALP, de Leva Resende BC, Sousa ACP, Dos Santos Freitas A....Endometritis is one of the main reproductive disorders in mares and due to the increasing prevalence of antibiotic resistance, the use of probiotics in the prevention and treatment of endometritis in mares has gained interest, given their potential to restore and maintain a healthy uterine microbiota. Therefore, the aim of this study was to evaluate the antimicrobial properties of total metabolites of Lactobacillus acidophilus (LA) and Lactiplantibacillus plantarum (LP) against common equine endometrial pathogenic bacteria in vitro (Acinetobacter baumannii, Escherichia coli (1), Escherichia co...
Nogacka AM, García A, de Los Reyes-Gavilán CG, Arboleya S, Gueimonde M.Horses are hindgut fermenters that harbor a complex intestinal microbiota (IM) which provides key enzymes aiding in the breakdown of complex carbohydrates present in their herbivorous diet. Therefore, these animals are deeply dependent on their IM for digestion and nutrition. Consequently, IM imbalances may result in alteration of fermentation patterns with impact on the animal health and the risk of disease. In this context, strategies for assisting the maintenance of a healthy IM in horses are of interest. However, there is limited research concerning the use of probiotics to improve hindgut...
Smith MZ, York M, Townsend KS, Martin LM, Gull T, Coghill LM, Ericsson AC, Johnson PJ.Whereas restoration of fecal consistency after treatment with clioquinol for chronic diarrhea and free fecal water syndrome has been attributed to its antiprotozoal properties, actions of clioquinol on the colonic bacterial microbiota have not been investigated. Objective: Characterize the dynamics of fecal microbial diversity before, during, and after PO administration of clioquinol to healthy horses. Methods: Experimental prospective cohort study using a single horse group. Methods: Eight healthy adult horses received PO clioquinol (10 g, daily) for 7 days. Feces were obtained daily for ...
Chow L, Kawahisa-Piquini G, Bass L, Hendrickson D, Patel A, Rockow M, Dow S, Pezzanite LM.Osteoarthritis (OA) is increasingly thought to be a multifactorial disease in which sustained gut inflammation serves as a continued source of inflammatory mediators driving degenerative processes at distant sites such as joints. The objective of this study was to use the equine model of naturally occurring obesity associated OA to compare the fecal microbiome in OA and health and correlate those findings to differential gene expression synovial fluid (SF) cells, circulating leukocytes and cytokine levels (plasma, SF) towards improved understanding of the interplay between microbiome and immun...
Brandi LA, Nunes AT, Faleiros CA, Poleti MD, Oliveira ECM, Schmidt NT, Sousa RLM, Fukumasu H, Balieiro JCC, Brandi RA.Different energy sources are often used in horse diets to enhance health and performance. Understanding how diet impacts the cecal and fecal microbiota is crucial for meeting the nutritional needs of horses. High-throughput sequencing and qPCR were used to compare the fecal and cecal microbiota of five healthy horses receiving three different diets: hay diet (HAY), hay + starch and sugar (SS), and hay + fiber and oil ingredients (FO). Assessment of short-chain fatty acids, pH, and buffer capacity was also performed. The HAY diet was associated with the highest values of fecal pH; the FO and SS...
Villa RE, Azimonti G, Bonos E, Christensen H, Durjava M, Dusemund B, Gehring R, Glandorf B, Kouba M, López-Alonso M, Marcon F, Nebbia C, Pechová A....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a preparation of CNCM I-1077 as a zootechnical feed additive for several animal species. The additive, existing in a not-coated and a coated form, is currently authorised for use in feed for calves, cattle for fattening, dairy cows, dairy goats and dairy sheep, lambs, all minor ruminant species for fattening and rearing, horses and camelids for fattening and rearing. This application regards the request for the extension of use in all ruminants and camelids reared for...
Vasseur M, Lepers R, Langevin N, Julliand S, Grimm P.This pilot study sought to explore the contribution of the large intestine microbiota to energy metabolism and exercise performance through its ability to degrade fibers into short-chain fatty acids (SCFAs). To investigate this, a correlational study was carried out on athlete horses under the same management conditions. Fecal microbiota diversity and composition, fibrolytic efficiency and SCFAs were analyzed. An incremental running test was carried out to estimate the maximal running speed (MRS) of the horses, and blood samples were taken to measure energy metabolism parameters. MRS was posit...
Thomson P, Garrido D, Santibáñez R, Lara F.The gut microbiome plays a critical role in maintaining horse health, influencing digestion, immunity, and overall well-being. However, in certain conditions like colic, there is evidence of significant alterations in the microbial community. To analyze the composition of the fecal microbiome and the enriched predicted metabolic functions of horses with colic compared to a control group, 14 horses with colic and 14 control horses were recruited. From a stool sample, DNA extraction was carried out for subsequent 16S rRNA metagenomic analysis. The composition of the microbiome was analyzed from ...
Bishop RC, Kemper AM, Clark LV, Wilkins PA, McCoy AM.Equine gastrointestinal microbial communities vary across the gastrointestinal tract and in response to diet or disease. Understanding the composition and stability of gastric fluid microbiota in healthy horses is a prerequisite to understanding changes associated with the development of disease. The objective of this study was to describe microbial communities in the gastric fluid and feces of healthy horses longitudinally. Horses were maintained on pasture (6 weeks), stabled (5 weeks), then returned to pasture. A consistent forage diet was provided throughout. Native gastric fluid and feces ...
Busch F, Leal ODA, Siebers N, Brüggemann N.During composting of organic waste, nitrogen is lost through gaseous forms and ion leaching. Biochar has been shown to capture mineral nitrogen (N: NH and NO ) from compost, which we hypothesize reduces NO formation. However, associating N captured by biochar with the dynamics of NO and other greenhouse gas (GHG) emissions during composting remains unstudied and was the aim of this work. We composted (outdoor for 148 days) together kitchen scraps (43.3% dw, where dw is dry weight), horse manure (40.9% dw), and wheat (Triticum aestivum L) straw (15.8% dw) without (Control) or with biochar (Bc,...
Fahey MJ, Harman RM, Thomas MA, Pugliese BR, Peters-Kennedy J, Delco ML, Van de Walle GR.We aimed to study the antimicrobial and pro-healing potential of equine mesenchymal stromal cell secreted products (i.e. secretome), collected as conditioned media (mesenchymal stromal cell-conditioned media, MSC CM), in a novel in vivo model of methicillin-resistant Staphylococcus aureus (MRSA)-inoculated equine thorax wounds. Methods: Prospective in vivo study. Methods: Two Thoroughbred geldings. Methods: Six full-thickness cutaneous wounds were created bilaterally on the dorsal thorax of two horses (n = 12 wounds/horse). Wounds on the left thoraces were inoculated with MRSA on day 0. Al...
Takahashi Y, Niwa H, Ebisuda Y, Mukai K, Yoshida T, Raidal S, Padalino B, Ohmura H.Protection of horse welfare during transport is crucial. The aim of this study was to determine the effect of head and neck restraint on behavior and airway bacteria. Unassigned: In a randomized crossover study, six healthy Thoroughbreds were transported by road for 22 h in an individual bay with tight head restraint (50 cm short-rope) or loose head restraint (95 cm long-rope). Behavioral parameters relating to head position, eating, and stress were monitored during transportation. Tracheal wash samples were obtained 6 days before and immediately after transport for bacterial culture a...
Samir A, Abdel-Moein KA, Zaher HM.The upsurge of diarrheagenic E. coli pathotypes carrying extended-spectrum beta-lactamases (ESBLs)/plasmid-mediated AmpC β-lactamase (pAmpC) among animals constitutes an emerging threat for humans and animals. This study investigated the burden of ESBL-/pAmpC-producing diarrheagenic E. coli among diarrheic foals and its potential public health implications. Rectal swabs were collected from 80 diarrheic foals. These swabs were processed to isolate and identify ESBL/pAmpC-producing E. coli using a selective culture medium, biochemical tests, phenotypic identification, and molecular identificati...
Tuniyazi M, Tang R, Hu X, Zhang N.Laminitis is a serious health condition that can cause severe pain and lameness in horses. Due to lack of understanding of laminitis, treatments often fail to achieve the desired results. In recent years, we have begun to recognize that laminitis may involve a complex interaction between local and systemic inflammation. Dysbiosis of the gut microbiota has been linked in the development of systemic inflammation, and our previous findings suggest that the development of laminitis is closely linked to the production of harmful metabolites of the gut microbiota. In addition, it was found that loca...
Martínez-Aranzales JR, Córdoba-Agudelo M, Pérez-Jaramillo JE.Crib-biting is a stereotyped oral behavior with poorly understood etiology and pathophysiology. The relationship between the gut microbiome and brain function has been described in behavioral disorders such as schizophrenia, depression and anxiety in humans. In horses, studies of behavioral problems and the microbiome are very limited. This study aimed to characterize the fecal microbiome and the predicted functional profile of horses with and without aerophagia. Fecal samples were collected from 12 Colombian Creole Horses of both sexes, divided into two groups: group 1, composed of six horses...
Eskola K, Aimo-Koivisto E, Heikinheimo A, Mykkänen A, Hautajärvi T, Grönthal T.Extended-spectrum β-lactamase -producing Enterobacterales (ESBL-E) are important zoonotic pathogens that can cause serious clinical infections, also in horses. Preventing the spread of ESBL-E, especially in the equine hospital environment, is key to reducing the number of difficult-to-treat infections. Estimating the local prevalence of ESBL-E in horses is crucial to establish targeted infection control programs at equine hospitals. We conducted a prevalence and risk factor study in equine patients on admission to an equine teaching hospital in Finland through a rectal ESBL-E screening specim...
Li Z, Luo Z, Hu D.Diarrhea serves as a vital health indicator for assessing wildlife populations post-reintroduction. Upon release into the wild, wild animals undergo adaptation to diverse habitats and dietary patterns. While such changes prompt adaptive responses in the fecal microbiota, they also render these animals susceptible to gastrointestinal diseases, particularly diarrhea. This study investigates variations in fecal microorganisms and hormone levels between diarrhea-afflicted and healthy Przewalski's horses. The results demonstrate a significant reduction in the alpha diversity of the fecal bacterial ...
Mann DN, Hobert KT, Biddle AS, Crossley MS.Cyathostomins are common digestive tract parasites of grazing horses that spread through contact with horse feces. Horse feces are colonized by a variety of organisms, some of which could serve to reduce parasite loads in horse pastures. Black soldier fly (Hermetia illucens L.; Diptera: Stratiomyidae) larvae (BSFL) could be an ideal candidate for biological control of cyathostomins, due to their near-global distribution, low risk of pathogen transmission, ability to develop on a variety of nutrient-poor substrates (including horse manure), and dramatic effect on microbial communities that cyat...
Żak-Bochenek A, Żebrowska-Różańska P, Bajzert J, Siwińska N, Madej JP, Kaleta-Kuratewicz K, Bochen P, Łaczmański Ł, Chełmońska-Soyta A.In the gastrointestinal mucosa, there is a close cooperation between secretory immunoglobulin A (SIgA) and the composition of the microbiota, which aims to maintain homeostasis as well as act as a protective barrier. The purpose of this study was to determine the composition of microbiota and SIgA production in different parts of the digestive tract (small intestine, cecum, colon and rectum) of nine healthy horses and its reflection in the feces. For this purpose, we determined: the composition of the microbiome (by next-generation Sequencing of Hypervariable Regions V3-V4 and V7-V9 of the 16...
Schoster A, Mosing M, Jalali M, Staempfli HR, Weese JS.The intestinal microbiota is important for health and disease. Factors that disturb the equine intestinal microbiota need further investigation. Objective: To determine the effects of transport, fasting and anaesthesia on the faecal microbiota of healthy adult horses using next-generation sequencing. Methods: Experimental trial. Methods: Faecal samples were taken from 8 horses at baseline, after transport, 12 h of fasting and 24, 48 and 72 h after a 6 h anaesthesia. Next generation sequencing of the V4 region of the 16S rRNA gene was used to assess the microbial composition of faeces. Alpha...
Julliand V, Grimm P.In the early 1990s, the equine hindgut microbial ecosystem looked like a "black box." Its vital role in hydrolyzing and fermenting fiber, thus providing energy to the host, was recognized. Although there was a critical lack of information on the hindgut microbes, their role in preventing intestinal diseases was suggested. Traditionally, the microbes of the horse hindgut were studied using culture-dependent techniques. More recently, culture-independent methods have been used and provided further insight. This review presents the history and updated knowledge regarding the microbes that live in...
Mach N, Foury A, Kittelmann S, Reigner F, Moroldo M, Ballester M, Esquerré D, Rivière J, Sallé G, Gérard P, Moisan MP, Lansade L.Weaning has been described as one of the most stressful events in the life of horses. Given the importance of the interaction between the gut-brain axis and gut microbiota under stress, we evaluated (i) the effect of two different weaning methods on the composition of gut microbiota across time and (ii) how the shifts of gut microbiota composition after weaning affect the host. A total of 34 foals were randomly subjected to a progressive (P) or an abrupt (A) weaning method. In the P method, mares were separated from foals at progressively increasing intervals every day, starting from five min ...
Julliand V, de Vaux A, Millet L, Fonty G.Detection and quantification of cellulolytic bacteria with oligonucleotide probes showed that Ruminococcus flavefaciens was the predominant species in the pony and donkey cecum. Fibrobacter succinogenes and Ruminococcus albus were present at low levels. Four isolates, morphologically resembling R. flavefaciens, differed from ruminal strains by their carbohydrate utilization and their end products of cellobiose fermentation.
Kauter A, Epping L, Semmler T, Antao EM, Kannapin D, Stoeckle SD, Gehlen H, Lübke-Becker A, Günther S, Wieler LH, Walther B.Understanding the complex interactions of microbial communities including bacteria, archaea, parasites, viruses and fungi of the gastrointestinal tract (GIT) associated with states of either health or disease is still an expanding research field in both, human and veterinary medicine. GIT disorders and their consequences are among the most important diseases of domesticated Equidae, but current gaps of knowledge hinder adequate progress with respect to disease prevention and microbiome-based interventions. Current literature on enteral microbiomes mirrors a vast data and knowledge imbalance, w...
Ahmed MO, Clegg PD, Williams NJ, Baptiste KE, Bennett M.Escherichia coli isolates of equine faecal origin were investigated for antibiotic resistance, resistance genes and their ability to perform horizontal transfer. Methods: In total, 264 faecal samples were collected from 138 horses in hospital and community livery premises in northwest England, yielding 296 resistant E. coli isolates. Isolates were tested for susceptibility to antimicrobial drugs by disc diffusion and agar dilution methods in order to determine minimum inhibitory concentrations (MIC). PCR amplification was used to detect genes conferring resistance to: ampicillin (TEM and SHV b...
Lin C, Stahl DA.A total of six 16S rRNA targeted oligonucleotide probes were used to quantify Fibrobacter abundance and diversity in the gastrointestinal contents of a pony. Approximately 12% of the total 16S rRNA extracted from cecal contents hybridized with a Fibrobacter genus-specific probe and a Fibrobacter succinogenes species-specific probe. However, no significant hybridization was observed with a probe for the species. Fibrobacter intestinalis or with three probes for F. succinogenes subspecies. This suggested the presence of a previously undescribed population of F. succinogenes-like organisms. Novel...
Morvan B, Bonnemoy F, Fonty G, Gouet P.Total number of bacteria, cellulolytic bacteria, and H2-utilizing microbial populations (methanogenic archaea, acetogenic and sulfate-reducing bacteria) were enumerated in fresh rumen samples from sheep, cattle, buffaloes, deer, llamas, and caecal samples from horses. Methanogens and sulfate reducers were found in all samples, whereas acetogenes were not detected in some samples of each animal. Archaea methanogens were the largest H2-utilizing populations in all animals, and a correlation was observed between the numbers of methanogens and those of cellulolytic microorganisms. Higher counts of...
Proudman CJ, Hunter JO, Darby AC, Escalona EE, Batty C, Turner C.The intestinal bacterial community of the horse is a key determinant of intestinal and whole body health. Understanding the bacterial community structure and function is an important foundation for studies of intestinal health and disease. Objective: To describe the faecal bacterial community and volatile organic compounds (VOCs) of the faecal metabolome of healthy Thoroughbred racehorses and to characterise responses to dietary supplementation with amylase-rich malt extract. Methods: Intervention study. Methods: Faecal samples were collected noninvasively before and 6 weeks after supplementat...
Zhao Y, Li B, Bai D, Huang J, Shiraigo W, Yang L, Zhao Q, Ren X, Wu J, Bao W, Dugarjaviin M.The hindgut of horses is an anaerobic fermentative chamber for a complex and dynamic microbial population, which plays a critical role in health and energy requirements. Research on the gut microbiota of Mongolian horses has not been reported until now as far as we know. Mongolian horse is a major local breed in China. We performed high-throughput sequencing of the 16S rRNA genes V4 hypervariable regions from gut fecal material to characterize the gut microbiota of Mongolian horses and compare them to the microbiota in Thoroughbred horses. Fourteen Mongolian and 19 Thoroughbred horses were use...
Bulmer LS, Murray JA, Burns NM, Garber A, Wemelsfelder F, McEwan NR, Hastie PM.Gut microbiota have been associated with health, disease and behaviour in several species and are an important link in gut-brain axis communication. Diet plays a key role in affecting the composition of gut microbiota. In horses, high-starch diets alter the hindgut microbiota. High-starch diets are also associated with increased behavioural reactivity in horses. These changes in microbiota and behaviour may be associated. This study compares the faecal microbiota and behaviour of 10 naïve ponies. A cross-over design was used with experimental groups fed high-starch (HS) or high-fibre (HF) die...
Kennedy R, Lappin DF, Dixon PM, Buijs MJ, Zaura E, Crielaard W, O'Donnell L, Bennett D, Brandt BW, Riggio MP.Equine periodontal disease is a common and painful condition and its severe form, periodontitis, can lead to tooth loss. Its aetiopathogenesis remains poorly understood despite recent increased awareness of this disorder amongst the veterinary profession. Bacteria have been found to be causative agents of the disease in other species, but current understanding of their role in equine periodontitis is extremely limited. The aim of this study was to use high-throughput sequencing to identify the microbiome associated with equine periodontitis and oral health. Subgingival plaque samples from 24 h...
Lindenberg F, Krych L, Kot W, Fielden J, Frøkiær H, van Galen G, Nielsen DS, Hansen AK.Shortly after birth the mammalian gut is colonized, by a transient microbiota, highly susceptible to environment and diet, that eventually stabilizes and becomes the resident gut microbiota. In a window of opportunity during the colonization, oral tolerance is established towards resident bacteria. In this study, the development of the equine gut microbiota was investigated in ten foals from parturition until post weaning. We found great differences in the core species of the gut microbiota composition between time-matched samples on Day 7 and 20 post-partum. Between day 20 and Day 50 post-par...
Medina B, Girard ID, Jacotot E, Julliand V.Eight horses were allotted into pairs consisting of one cecum- and right ventral colon-fistulated animal and one cecum-fistulated animal. They were fed daily at the same level of intake either a high-fiber (HF) or a high-starch (HS) diet without or with 10 g of a Saccharomyces cerevisiae preparation, in a 4 x 4 Latin square design. The HS diet provided a starch overload (i.e., 3.4 g starch x kg(-1) BW x meal(-1)) while maintaining a high amount of fiber intake (i.e., dietary NDF/starch ratio was 1.0). A 21-d period of adaptation to the treatments occurred before cecal and colonic contents were...
Milinovich GJ, Trott DJ, Burrell PC, van Eps AW, Thoefner MB, Blackall LL, Al Jassim RA, Morton JM, Pollitt CC.In the horse, carbohydrate overload is thought to play an integral role in the onset of laminitis by drastically altering the profile of bacterial populations in the hindgut. The objectives of this study were to develop and validate microbial ecology methods to monitor changes in bacterial populations throughout the course of experimentally induced laminitis and to identify the predominant oligofructose-utilizing organisms. Laminitis was induced in five horses by administration of oligofructose. Faecal specimens were collected at 8 h intervals from 72 h before to 72 h after the administration ...
Perkins GA, den Bakker HC, Burton AJ, Erb HN, McDonough SP, McDonough PL, Parker J, Rosenthal RL, Wiedmann M, Dowd SE, Simpson KW.Little is known about the gastric mucosal microbiota in healthy horses, and its role in gastric disease has not been critically examined. The present study used a combination of 16S rRNA bacterial tag-encoded pyrosequencing (bTEFAP) and fluorescence in situ hybridization (FISH) to characterize the composition and spatial distribution of selected gastric mucosal microbiota of healthy horses. Biopsy specimens of the squamous, glandular, antral, and any ulcerated mucosa were obtained from 6 healthy horses by gastroscopy and from 3 horses immediately postmortem. Pyrosequencing was performed on bio...
Schoster A, Weese JS, Guardabassi L.The gastrointestinal microbiota is extremely important for human and animal health. Investigations into the composition of the microbiota and its therapeutic modification have received increasing interest in human and veterinary medicine. Probiotics are a way of modifying the microbiota and have been tested to prevent and treat diseases. Probiotics are proposed to exert their beneficial effects through various pathways. Production of antimicrobial compounds targeting intestinal pathogens, general immune stimulation, and colonization resistance are among these mechanisms. Despite widespread ava...
Schoster A, Staempfli HR, Guardabassi LG, Jalali M, Weese JS.Diarrhea in foals affects up to 60% of foals during the first six months of life. The effect of diarrhea on the fecal bacterial microbiota in foals has not been investigated. Little is known on the fecal bacterial microbial richness and diversity of foals at a young age. The objective was to compare the fecal bacterial microbiota of healthy foals to foals with diarrhea at two and four weeks of life. Methods: Fecal samples were collected from foals (n = 20) at 1-14 (T1) and 15-28 (T2) days of age and analyzed using high throughput sequencing. Differences in relative abundance of bacterial tax...
Chaucheyras-Durand F, Sacy A, Karges K, Apper E.Horses are large non-ruminant herbivores and rely on microbial fermentation for energy, with more than half of their maintenance energy requirement coming from microbial fermentation occurring in their enlarged caecum and colon. To achieve that, the gastro-intestinal tract (GIT) of horses harbors a broad range of various microorganisms, differing in each GIT segment, which are essential for efficient utilization of feed, especially to use nutrients that are not or little degraded by endogenous enzymes. In addition, like in other animal species, the GIT microbiota is in permanent interplay with...
Milinovich GJ, Burrell PC, Pollitt CC, Klieve AV, Blackall LL, Ouwerkerk D, Woodland E, Trott DJ.Alimentary carbohydrate overload is a significant cause of laminitis in horses and is correlated with drastic shifts in the composition of hindgut microbiota. Equine hindgut streptococcal species (EHSS), predominantly Streptococcus lutetiensis, have been shown to be the most common microorganisms culturable from the equine caecum prior to the onset of laminitis. However, the inherent biases of culture-based methods are estimated to preclude up to 70% of the normal caecal microbiota. The objective of this study was to evaluate bacterial population shifts occurring in the equine caecum throughou...
Walshe N, Duggan V, Cabrera-Rubio R, Crispie F, Cotter P, Feehan O, Mulcahy G.The interactions between parasitic helminths and gut microbiota are considered to be an important, although as yet incompletely understood, factor in the regulation of immunity, inflammation and a range of diseases. Infection with intestinal helminths is ubiquitous in grazing horses, with cyathostomins (about 50 species of which are recorded) predominating. Consequences of infection include both chronic effects, and an acute inflammatory syndrome, acute larval cyathostominosis, which sometimes follows removal of adult helminths by administration of anthelmintic drugs. The presence of cyathosto...
Li C, Li X, Guo R, Ni W, Liu K, Liu Z, Dai J, Xu Y, Abduriyim S, Wu Z, Zeng Y, Lei B, Zhang Y, Wang Y, Zeng W, Zhang Q, Chen C, Qiao J, Liu C, Hu S.As a domesticated species vital to humans, horses are raised worldwide as a source of mechanical energy for sports, leisure, food production, and transportation. The gut microbiota plays an important role in the health, diseases, athletic performance, and behaviour of horses. Here, using approximately 2.2 Tb of metagenomic sequencing data from gut samples from 242 horses, including 110 samples from the caecum and 132 samples from the rectum (faeces), we assembled 4142 microbial metagenome-assembled genomes (MAG), 4015 (96.93%) of which appear to correspond to new species. From long-read data, ...
McKinney CA, Oliveira BCM, Bedenice D, Paradis MR, Mazan M, Sage S, Sanchez A, Widmer G.Fecal microbial transplantation (FMT), a treatment for certain gastrointestinal conditions associated with dysbiosis in people, is also empirically employed in horses with colitis. This study used microbiota high-throughput sequencing to compare the fecal microbial profile of healthy horses to that of geriatric microbial transplant recipients experiencing diarrhea and tested whether FMT restores microbiota diversity. To evaluate the effect of environment and donor characteristics on the intestinal microbiota, fecal samples were collected per rectum from 15 healthy young-adult (2-12 years) and ...
Glinsky MJ, Smith RM, Spires HR, Davis CL.Three experiments, each utilizing three ponies, were conducted using a mixed VFA solution of [1−14C] acetate, [1−14C] propionate and [2–33H] butyrate to determine VFA production rates in the cecum of the pony. Diet A used in experiment 1, contained a forage to grain ratio of 1:2, while diet B, used in experiments 2 and 3, contained a forage to grain ratio of 3:1. Experiment 1, in which a constant infusion technique was used, resulted in net VFA production rates (mmoles/min) of 3.667 to 3.977 (x̄=3.836) for acetate, .410 to 1.664 (x̄=1.213) for propionate and .342 to 1.124 (x̄=.629) fo...
Santos AS, Rodrigues MA, Bessa RJ, Ferreira LM, Martin-Rosset W.Having evolved as a grazing animal, a horse's digestive physiology is characterized by rapid gastric transit, a rapid but intense enzymatic digestion along the small intestine, and a long and intense microbial fermentation in the large intestine. The process of understanding and describing feed degradation mechanisms in the equine digestive system in general, and in the hindgut ecosystem in particular, is essential. Regardless of its importance for the nutritional status of the host, the significance of the cecum-colon ecosystem has not yet been fully understood, and few reports have focused d...
Moreau MM, Eades SC, Reinemeyer CR, Fugaro MN, Onishi JC.In the equine carbohydrate overload model of acute laminitis, disease progression is associated with changes in bacteria found in the cecum. To date, research has focused on changes in specific Gram-positive bacteria in this portion of the intestinal tract. Metagenomic methods are now available making it possible to interrogate microbial communities using animal protocols that sufficiently power a study. In this study, the microbiota in cecal fluid collected from control, non-laminitic horses (n=8) and from horses with early-stage acute laminitis induced with either oligofructan (n=6) or corns...
Clark A, Sallé G, Ballan V, Reigner F, Meynadier A, Cortet J, Koch C, Riou M, Blanchard A, Mach N.Gastrointestinal strongyles are a major threat to horses' health and welfare. Given that strongyles inhabit the same niche as the gut microbiota, they may interact with each other. These beneficial or detrimental interactions are unknown in horses and could partly explain contrasted susceptibility to infection between individuals. To address these questions, an experimental pasture trial with 20 worm-free female Welsh ponies (10 susceptible (S) and 10 resistant (R) to parasite infection) was implemented for 5 months. Fecal egg counts (FEC), hematological and biochemical data, body weight and g...
Liu G, Bou G, Su S, Xing J, Qu H, Zhang X, Wang X, Zhao Y, Dugarjaviin M.Gastrointestinal microbiota has significant impact on the nutrition and health of monogastric herbivores animals including donkey. However, so far the microbiota in different gastrointestinal compartments of healthy donkey has not been described. Therefore, we investigated the abundance and function of microbiota at different sites of the gastrointestinal tract (GIT) (foregut: stomach, duodenum, jejunum and ileum; hindgut: cecum, ventral colon, dorsal colon, and rectum) of healthy adult donkeys mainly based on 16S rRNA gene sequencing and phylogenetic investigation of communities by reconstruc...
Ang L, Vinderola G, Endo A, Kantanen J, Jingfeng C, Binetti A, Burns P, Qingmiao S, Suying D, Zujiang Y, Rios-Covian D, Mantziari A, Beasley S....Domesticated horses live under different conditions compared with their extinct wild ancestors. While housed, medicated and kept on a restricted source of feed, the microbiota of domesticated horses is hypothesized to be altered. We assessed the fecal microbiome of 57 domestic and feral horses from different locations on three continents, observing geographical differences. A higher abundance of eukaryota (p < 0.05) and viruses (p < 0.05) and lower of archaea (p < 0.05) were found in feral animals when compared with domestic ones. The abundance of genes coding for microbe-...
De La Torre U, Henderson JD, Furtado KL, Pedroja M, Elenamarie O, Mora A, Pechanec MY, Maga EA, Mienaltowski MJ.A healthy gastrointestinal (GI) tract with a properly established microbiota is necessary for a foal to develop into a healthy weanling. A foal's health can be critically impacted by aberrations in the microbiome such as with diarrhea which can cause great morbidity and mortality in foals. In this study, we hypothesized that gut establishment in the foal transitioning from a diet of milk to a diet of grain, forage, and pasture would be detectable through analyses of the fecal microbiotas. Fecal samples from 37 sets of foals and mares were collected at multiple time points ranging from birth to...
