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.
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...
Bell J, Radial SL, Cuming RS, Trope G, Hughes KJ.Diarrhea in foals can be associated with disruption of the intestinal microbiota (dysbiosis). Effective management of intestinal dysbiosis in foals has not been demonstrated. Objective: Fecal microbiota transplantation (FMT) in foals with diarrhea influences the intestinal microbiota and improves clinical and clinicopathological outcomes. Methods: Twenty-five foals <6 months of age with diarrhea and systemic inflammatory response syndrome at 3 veterinary hospitals. Methods: A prospective randomized placebo-controlled cohort study. Foals in the FMT group (n = 19) or control group (n =...
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...
Sävilammi T, Alakangas RR, Häyrynen T, Uusi-Heikkilä S.Gastrointestinal disorders are common and debilitating in horses, but their diagnosis is often difficult and invasive. Fecal samples offer a non-invasive alternative to assessing the gastrointestinal health of horses by providing information about the gut microbiota and inflammation. In this study, we used 16S sequencing to compare the fecal bacterial diversity and composition of 27 healthy horses and 49 horses diagnosed with inflammatory bowel disease (IBD). We also measured fecal calprotectin concentration, a marker of intestinal inflammation, in healthy horses and horses with IBD. We found ...
Leng J, Moller-Levet C, Mansergh RI, O'Flaherty R, Cooke R, Sells P, Pinkham C, Pynn O, Smith C, Wise Z, Ellis R, Couto Alves A, La Ragione R....Gut bacterial communities have a profound influence on the health of humans and animals. Early-life gut microbial community structure influences the development of immunological competence and susceptibility to disease. For the Thoroughbred racehorse, the significance of early-life microbial colonisation events on subsequent health and athletic performance is unknown. Here we present data from a three-year cohort study of horses bred for racing designed to explore interactions between early-life gut bacterial community structure, health events in later life and athletic performance on the race...
Bell J, Raidal S, Peters A, Hughes KJ.Management of diarrhoea in horses is usually non-specific and supportive. Faecal microbiota transplantations (FMT) are used to manage dysbiosis in horses with diarrhoea. There are few studies investigating the effects of storage on prepared FMT solutions. This study was an in vitro non-randomised controlled experiment that investigated the effects of FMT solution preparation and storage on the faecal microbiota. Fresh faeces were collected from five healthy adult horses and used for DNA extraction and preparation of FMT. From each FMT, seven aliquots were collected and DNA was extracted immedi...
Froidurot A, Jacotot E, Julliand S, Grimm P, Julliand V.Despite their low quantity and abundance, the cellulolytic bacteria that inhabit the equine large intestine are vital to their host, as they enable the crucial use of forage-based diets. Fibrobacter succinogenes is one of the most important intestinal cellulolytic bacteria. In this study, Fibrobacter sp. HC4, one cellulolytic strain newly isolated from the horse cecum, was characterized for its ability to utilize plant cell wall fibers. Fibrobacter sp. HC4 consumed only cellulose, cellobiose, and glucose and produced succinate and acetate in equal amounts. Among genes coding for CAZymes, 26% o...
Bachmann M, Schusser GF, Wensch-Dorendorf M, Pisch C, Bochnia M, Santo MM, Netzker H, Woitow G, Thielebein J, Kesting S, Riehl G, Greef JM....Concentrations of starch, mono- and disaccharides, fructans, hemicellulose and cellulose were analysed in feed and gastric digesta of horses in relation to acid insoluble ash as a marker indigestible in the stomach. Twenty-four horses were allocated to pasture 24 h/d (PST; n = 4), hay ad libitum (HAY; n = 8), hay ad lib. and oats at 1 g starch/kg body weight (BWT)/meal (OS1; n = 6) and hay ad lib. and oats at 2 g starch/kg BWT/meal (OS2; n = 5). One horse was excluded from the analysis. The horses were fed the ration a minimum of 34 days. Following euthanasia and dissection, digesta was sample...
Stothart MR, McLoughlin PD, Medill SA, Greuel RJ, Wilson AJ, Poissant J.Gut microbiomes are widely hypothesised to influence host fitness and have been experimentally shown to affect host health and phenotypes under laboratory conditions. However, the extent to which they do so in free-living animal populations and the proximate mechanisms involved remain open questions. In this study, using long-term, individual-based life history and shallow shotgun metagenomic sequencing data (2394 fecal samples from 794 individuals collected between 2013-2019), we quantify relationships between gut microbiome variation and survival in a feral population of horses under natural...
Long AE, Pitta D, Hennessy M, Indugu N, Vecchiarelli B, Luethy D, Aceto H, Hurcombe S.Currently, lack of standardization for fecal microbiota transplantation (FMT) in equine practice has resulted in highly variable techniques, and there is no data on the bacterial metabolic activity or viability of the administered product. The objectives of this study were to compare the total and potentially metabolically active bacterial populations in equine FMT, and assess the effect of different frozen storage times, buffers, and temperatures on an equine FMT product. Fresh feces collected from three healthy adult horses was subjected to different storage methods. This included different ...
Hu L, Li X, Li C, Wang L, Han L, Ni W, Zhou P, Hu S.The gut microbiota is a treasure trove of carbohydrate-active enzymes (CAZymes). To explore novel and efficient CAZymes, we analyzed the 4,142 metagenome-assembled genomes (MAGs) of the horse gut microbiota and found the MAG117.bin13 genome (Bacteroides fragilis) contains the highest number of polysaccharide utilisation loci sites (PULs), indicating its high capability for carbohydrate degradation. Bioinformatics analysis indicate that the PULs region of the MAG117.bin13 genome encodes many hypothetical proteins, which are important sources for exploring novel CAZymes. Interestingly, we discov...
Bell J, Raidal SL, Hughes KJ.Changes to the faecal microbiota of horses associated with administration of anthelmintic drugs is poorly defined. This study included horses with cyathostomin infection where susceptibility and resistance to oxfendazole and abamectin was known. This study assessed the changes to the faecal microbiota associated with administration of two different anthelmintics in this population. Twenty-four adult horses were included. Faecal egg counts were performed on all horses prior to random allocation into abamectin (n=8), oxfendazole (n=8) or Control groups (n=8) and at Day 14 post treatment. Faecal ...
Lin J, Jing H, Wang J, Lucien-Cabaraux JF, Yang K, Liu W, Li X.The nutritional benefits of mare milk are attracting increasing consumer interest. Limited availability due to low yield poses a challenge for widespread adoption. Although lysine and threonine are often used to enhance protein synthesis and muscle mass in horses, their impact on mare milk yield and nutrient composition remains underexplored. This study investigated the effects of lysine and threonine supplementation on 24 healthy Yili mares, mares at day 30 of lactation, over a 120-day period. The mares were divided into control and three experimental groups (six mares each) under pure grazin...
Bishop RC, Migliorisi A, Holmes JR, Kemper AM, Band M, Austin S, Aldridge B, Wilkins PA.Understanding normal microbial populations within areas of the respiratory tract is essential, as variable regional conditions create different niches for microbial flora, and proliferation of commensal microbes likely contributes to clinical respiratory disease. The objective was to describe microbial population variability between respiratory tract locations in healthy horses. Samples were collected from four healthy adult horses by nasopharyngeal lavage (NPL), transtracheal aspirate (TTA), and bronchoalveolar lavage (BAL) of six distinct regions within the lung. Full-length 16S ribosomal DN...
Heil BA, van Heule M, Thompson SK, Kearns TA, Beckers KF, Oberhaus EL, King G, Daels P, Dini P, Sones JL.The equine uterus is highly interrogated during estrus prior to breeding and establishing pregnancy. Many studies in mares have been performed during estrus under the influence of high estrogen concentrations, including the equine estrual microbiome. To date, it is unknown how the uterine microbiome of the mare is influenced by cyclicity; while, the equine vaginal microbiome is stable throughout the estrous cycle. We hypothesized that differences would exist between the equine endometrial microbiome of mares in estrus and anestrus. The aim of this study was two-fold: to characterize the reside...
Wester RJ, Baillie LL, McCarthy GC, Keever CC, Jeffery LE, Adams PJ.Free Fecal Liquid (FFL), also termed Fecal Water Syndrome (FWS), is an ailment in horses characterized by variable solid and liquid (water) phases at defecation. The liquid phase can be excreted before, during, or after the solid defecation phase. While the underlying causes of FFL are unknown, hindgut dysbiosis is suggested to be associated with FFL. Three European studies investigated dysbiosis in horses with FFL using 16S rRNA sequencing and reported results that conflicted between each other. In the present study, we also used 16S rRNA sequencing to study the fecal microbial composition in...
Baraille M, Buttet M, Grimm P, Milojevic V, Julliand S, Julliand V.Horse owners and veterinarians report that from the age of 15, their horses can lose body condition and be more susceptible to diseases. Large intestinal microbiome changes may be involved. Indeed, microbiota is crucial for maintaining the condition and health of herbivores by converting fibres into nutrients. This study aimed to compare the faecal microbiome in horses aged from 6 to 30 years old (yo), living in the same environment and consuming the same diet, in order to assess whether the parameters changed linearly with age and whether there was a pivotal age category. Fifty horses were se...
Kawaida MY, Maas KR, Moore TE, Reiter AS, Tillquist NM, Reed SA.To determine the effects of astaxanthin (ASTX) supplementation on the equine gut microbiota during a deconditioning-reconditioning cycle, 12 polo ponies were assigned to a control (CON; n = 6) or supplemented (ASTX; 75 mg ASTX daily orally; n = 6) group. All horses underwent a 16-week deconditioning period, with no forced exercise, followed by a 16-week reconditioning program where physical activity gradually increased. Fecal samples were obtained at the beginning of the study (Baseline), after deconditioning (PostDecon), after reconditioning (PostRecon), and 16 weeks after the ces...
Raspa F, Chessa S, Bergero D, Sacchi P, Ferrocino I, Cocolin L, Corvaglia MR, Moretti R, Cavallini D, Valle E.Diet is one of the main factors influencing the intestinal microbiota in horses, yet a systematic characterization of the microbiota along the length of the digestive tract in clinically healthy horses, homogenous for age and breed and receiving a specific diet is lacking. Unassigned: The study used 16S rRNA amplicon sequencing to characterize the microbiota of the intestinal tracts of 19 healthy Bardigiano horses of 14.3 ± 0.7 months of age fed one of two diets. Nine horses received a high-starch diet (HS), and ten horses received a high-fiber diet (HF). After 129 days, the horse...
Mach N, Ruet A, Clark A, Bars-Cortina D, Ramayo-Caldas Y, Crisci E, Pennarun S, Dhorne-Pollet S, Foury A, Moisan MP, Lansade L.We simultaneously measured the fecal microbiota and multiple environmental and host-related variables in a cohort of 185 healthy horses reared in similar conditions during a period of eight months. The pattern of rare bacteria varied from host to host and was largely different between two time points. Among a suite of variables examined, equitation factors were highly associated with the gut microbiota variability, evoking a relationship between gut microbiota and high levels of physical and mental stressors. Behavioral indicators that pointed toward a compromised welfare state (e.g. stereotyp...
Blackmore TM, Dugdale A, Argo CM, Curtis G, Pinloche E, Harris PA, Worgan HJ, Girdwood SE, Dougal K, Newbold CJ, McEwan NR.The horse, as a hindgut fermenter, is reliant on its intestinal bacterial population for efficient diet utilisation. However, sudden disturbance of this population can result in severe colic or laminitis, both of which may require euthanasia. This study therefore aimed to determine the temporal stability of the bacterial population of faecal samples from six ponies maintained on a formulated high fibre diet. Bacterial 16S rRNA terminal restriction fragment length polymorphism (TRFLP) analyses of 10 faecal samples collected from 6 ponies at regular intervals over 72 hour trial periods identifie...
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...
Mackie RI, Wilkins CA.Samples from the duodenum, jejunum, and ileum, as well as from the cecum and colon, were obtained from 11 mature grass-fed horses. Viable counts of total culturable and proteolytic bacteria were made on habitat-simulating media containing 40% clarified ruminal fluid. The mean pHs in the duodenum, jejunum, and ileum were 6.32, 7.10, and 7.47, respectively; the mean pH decreased to 6.7 in the hindgut. The acetate concentration increased along the length of the small intestine and was the only volatile fatty acid present in this gut segment. Molar proportions of acetate, propionate, and butyrate ...
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...
Milinovich GJ, Trott DJ, Burrell PC, Croser EL, Al Jassim RA, Morton JM, van Eps AW, Pollitt CC.Carbohydrate-induced laminitis in horses is characterized by marked changes in the composition of the hindgut microbiota, from a predominantly Gram-negative population to one dominated by Gram-positive bacteria. The objective of this study was to monitor changes in the relative abundance of selected hindgut bacteria that have previously been implicated in the pathophysiology of equine laminitis using fluorescence in situ hybridization (FISH). Caecal cannulae were surgically implanted in five Standardbred horses and laminitis induced by oral administration of a bolus dose of oligofructose. Caec...
Kunz IGZ, Reed KJ, Metcalf JL, Hassel DM, Coleman RJ, Hess TM, Coleman SJ.The gastrointestinal microbiota (GIM) plays an essential role in maintaining intestinal homeostasis with disruptions having profound effects on the wellbeing of the host animal. Parasitic infection is a long-standing issue for the equine industry, and the use of anthelmintic drugs for parasite control has long been standard practice. The impact of anthelmintic treatment on the GIM in healthy horses is not well known. This study evaluated the hypothesis that anthelmintic administration will alter the equine fecal microbiota in horses without an observed helminth infection. Ten horses were treat...
Plancade S, Clark A, Philippe C, Helbling JC, Moisan MP, Esquerré D, Le Moyec L, Robert C, Barrey E, Mach N.An integrated analysis of gut microbiota, blood biochemical and metabolome in 52 endurance horses was performed. Clustering by gut microbiota revealed the existence of two communities mainly driven by diet as host properties showed little effect. Community 1 presented lower richness and diversity, but higher dominance and rarity of species, including some pathobionts. Moreover, its microbiota composition was tightly linked to host blood metabolites related to lipid metabolism and glycolysis at basal time. Despite the lower fiber intake, community type 1 appeared more specialized to produce ace...
Respondek F, Goachet AG, Julliand V.Prebiotic compounds, such as short-chain fructooligosaccharides (scFOS), have been shown to improve health, welfare, or both, in several species, but few studies have been conducted in horses, despite the sensitivity of their hindgut microflora. We hypothesized that prebiotic oligosaccharides, known to be able to stabilize the intestinal microflora in other species, would be of importance in horses. Our study was designed to evaluate the effect of scFOS supplementation on the equine intestinal microflora and to assess its effectiveness in reducing hindgut microbial disturbances related to sudd...
Su S, Zhao Y, Liu Z, Liu G, Du M, Wu J, Bai D, Li B, Bou G, Zhang X, Dugarjaviin M.The intestinal microbiota plays an important role in the health and metabolism of the host. Next-generation sequencing technology has enabled the characterization of the gut microbiota of several animal species. We analyzed the intestinal microbiota in six different parts of the gastrointestinal tracts (GITs) of five Mongolian horses by sequencing the 16S rRNA gene V3-V4 hypervariable region. All horses were kept in the natural habitat of the Inner Mongolia grassland. Significant differences were observed among the microbiota compositions of the distinct GIT regions. In addition, while the mic...
Harlow BE, Lawrence LM, Hayes SH, Crum A, Flythe MD.Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assigned to treatments: control (hay only), HC (high corn), HO (high oats), LC (low corn), LO (low oats), and LW (low pelleted wheat middlings). Horses received an all-forage diet (2 wk; d -14 to d -1) before the treatment diets (2 wk; d 1 to 14). Starch was introduced gradually so that horses received 50...
Jensen-Jarolim E, Pacios LF, Bianchini R, Hofstetter G, Roth-Walter F.Owners and their domestic animals via skin shedding and secretions, mutually exchange microbiomes, potential pathogens and innate immune molecules. Among the latter especially lipocalins are multifaceted: they may have an immunomodulatory function and, furthermore, they represent one of the most important animal allergen families. The amino acid identities, as well as their structures by superposition modeling were compared among human lipocalins, hLCN1 and hLCN2, and most important animal lipocalin allergens, such as Can f 1, Can f 2 and Can f 4 from dog, Fel d 4 from cats, Bos d 5 from cow's...
Flickinger EA, Van Loo J, Fahey GC.Inulin and oligofructose are prebiotic oligosaccharides fermented in the large intestine. This article provides an extensive review of the effects of these oligosaccharides on gastrointestinal characteristics (microflora, pathogen control, epithelial cell proliferation, putrefactive compound production, fecal characteristics, and nutrient digestibility) and systemic metabolism of carbohydrates, nitrogen, lipids, and minerals in dogs, cats, horses, calves, pigs, poultry, and rabbits. In addition, intake of inulin and oligofructose and considerations in their supplementation to animal diets are ...
Garner HE, Moore JN, Johnson JH, Clark L, Amend JF, Tritschler LG, Coffmann JR, Sprouse RF, Hutcheson DP, Salem CA.Caecal fluid samples collected 8 and 24 hours after carbohydrate overload were quantitatively compared to control samples in terms of aerobic and anaerobic bacteria. Concomitant increases in lactic acid-producing bacteria and decreases in Gram negative bacteria were substantiated during the onset of acute laminitis. Progressive decreases in caecal fluid pH were also quantitated. Although endotoxin assays of caecal fluid and blood were not done, the caecal flora changes suggest its presence during the onset of acute laminitis.
Fillion-Bertrand G, Dickson RP, Boivin R, Lavoie JP, Huffnagle GB, Leclere M.There is evidence that the lung microbiome differs between patients with asthma and healthy humans, but the effect of environmental conditions and medication is unknown and difficult to study. Equine asthma is a naturally occurring chronic airway disease characterized by reversible airway inflammation and bronchoconstriction upon exposure to inhaled antigens. In the present study, we evaluated the effect that environmental conditions and disease status have on pulmonary, nasal, and oral microbiomes. Six asthmatic and six healthy horses were studied while at pasture ("low antigen exposure"), as...
Swanson SP, Helaszek C, Buck WB, Rood HD, Haschek WM.The role of faecal and intestinal microflora on the metabolism of trichothecene mycotoxins was examined in this study. Suspensions of microflora obtained from the faeces of horses, cattle, dogs, rats, swine and chickens were incubated anaerobically with the trichothecene mycotoxin, diacetoxyscirpenol (DAS). Micro-organisms from rats, cattle and swine completely biotransformed DAS, primarily to the deacylated deepoxidation products, deepoxy monoacetoxyscirpenol (DE MAS) and deepoxy scirpentriol (DE SCP). By contrast, faecal microflora from chickens, horses and dogs failed to reduce the epoxide ...
Al Jassim RA, Scott PT, Trebbin AL, Trott D, Pollitt CC.Seventy-two lactic acid producing bacterial isolates (excluding streptococci) were cultured from the gastrointestinal tract of six horses. Two of the horses were orally dosed with raftilose to induce lactic acidosis and laminitis while the remaining four were maintained on a roughage diet. Near complete 16S rDNA was amplified by PCR from the genomic DNA of each isolate. Following RFLP analysis with the restriction enzymes MboI, HhaI and HinfI, the PCR products from the 18 isolates that produced L- and/or D-lactate were subsequently cloned and sequenced. DNA sequence analysis indicated that the...
McKinney CA, Bedenice D, Pacheco AP, Oliveira BCM, Paradis MR, Mazan M, Widmer G.Fecal microbial transplantation (FMT) is empirically implemented in horses with colitis to facilitate resolution of diarrhea. The purpose of this study was to assess FMT as a clinical treatment and modulator of fecal microbiota in hospitalized horses with colitis. A total of 22 horses with moderate to severe diarrhea, consistent with a diagnosis of colitis, were enrolled at two referral hospitals (L1: n = 12; L2: n = 10). FMT was performed in all 12 patients on 3 consecutive days at L1, while treatment at L2 consisted of standard care without FMT. Manure was collected once daily for 4 days fro...
Mullen KR, Yasuda K, Divers TJ, Weese JS.While certainly not a novel concept, faecal microbiota transplant (FMT) has recently garnered renewed interest in veterinary medicine due to its remarkable success in treating recurrent Clostridium difficile infection (CDI) in man. There is a dearth of information on indications and efficacy of FMT for the treatment of gastrointestinal disorders in the horse; however, based on evidence in man and other veterinary species, and anecdotal reports in horses, FMT may be a useful treatment for selected cases of acute and chronic diarrhoea and inflammatory bowel disease (IBD) in the horse. In the abs...
Massacci FR, Clark A, Ruet A, Lansade L, Costa M, Mach N.Understanding gut microbiota similarities and differences across breeds in horses has the potential to advance approaches aimed at personalized microbial modifications, particularly those involved in improving sport athletic performance. Here, we explore whether faecal microbiota composition based on faecal 16S ribosomal RNA gene sequencing varies across six different sport breeds at two time points 8 months apart within a cohort of 189 healthy horses cared for under similar conditions. Lusitano horses presented the smallest and Hanoverians the greatest bacterial diversity. We found subtle bu...
Arroyo LG, Rossi L, Santos BP, Gomez DE, Surette MG, Costa MC.The aim of this study was to compare the mucosal and luminal content microbiota of the cecum and colon of healthy and diarrheic horses. Marked differences in the richness and in the community composition between the mucosal and luminal microbiota of the cecum and large colon of horses with colitis were observed. Microbial dysbiosis occurs in horses with colitis at different levels of the intestinal tract, and microbiota composition is different between the mucosa and luminal content of diarrheic horses. The changes in some key taxa associated with dysbiosis in the equine intestinal microbiota,...
Grimm P, Combes S, Pascal G, Cauquil L, Julliand V.Starchy diets can induce hindgut dysbiosis in horses. The present study evaluated the impact of a yeast (Saccharomyces cerevisiae) and microalgae (Aurantiochytrium limacinum) supplementation on caecal, colonic and faecal microbial ecosystem and on blood inflammatory parameters of horses fed high-fibre or high-starch diets. Six fistulated geldings in a 2 × 2 Latin-square design were alternatively supplemented and received during each period 100 % hay (4 weeks) followed by a 56/44 hay/barley diet (3 weeks). Caecal, colonic and faecal samples were collected 4 h after the morning meal three times...
Warzecha CM, Coverdale JA, Janecka JE, Leatherwood JL, Pinchak WE, Wickersham TA, McCann JC.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 libit...
Freeman K, Woods E, Welsby S, Percival SL, Cochrane CA.Evidence of biofilms in human chronic wounds are thought to be responsible for preventing healing in a timely manner. However, biofilm evidence in horse wounds has not yet been documented. Consequently, this study aimed to determine whether biofilms could be detected in wounds, and to investigate the microbiology of chronic wounds in horses. Prior to analysis, wound surfaces were irrigated with 5 mL of sterile saline to remove debris. All wounds were swabbed twice (1 cm2 area) using sterile cotton-tipped swabs. In addition to this, 2 tissue biopsies were taken to investigate evidence of biofil...
