Mining the equine gut metagenome: poorly-characterized taxa associated with cardiovascular fitness in endurance athletes

Abstract

Emerging evidence indicates that the gut microbiome contributes to endurance exercise performance. Still, the extent of its functional and metabolic potential remains unknown. Using elite endurance horses as a model system for exercise responsiveness, we built an integrated horse gut gene catalog comprising ~25 million unique genes and 372 metagenome-assembled genomes. This catalog represents 4179 genera spanning 95 phyla and functional capacities primed to exploit energy from dietary, microbial, and host resources. The holo-omics approach shows that gut microbiomes enriched in Lachnospiraceae taxa are negatively associated with cardiovascular capacity. Conversely, more complex and functionally diverse microbiomes are associated with higher glucose concentrations and reduced accumulation of long-chain acylcarnitines and non-esterified fatty acids in plasma, suggesting increased ß-oxidation capacity in the mitochondria. In line with this hypothesis, more fit athletes show upregulation of mitochondrial-related genes involved in energy metabolism, biogenesis, and Ca2+ cytosolic transport, all of which are necessary to improve aerobic work power, spare glycogen usage, and enhance cardiovascular capacity. The results identify an associative link between endurance performance and gut microbiome composition and gene function, laying the basis for nutritional interventions that could benefit horse athletes.

Species interactions, stability, and resilience of the gut microbiota - Helminth assemblage in horses

“…They also exhibited higher concentrations of fecal DNA ( Figure 2 C; adj p = 9.48e −07 ). This is suggestive of higher microbial and parasite (eggs) biomass, but also host-derived contents from epithelial cells and blood-shedding into the lumen as reported in horses with gut inflammation after strenuous exercise 52 and patients with Crohn’s disease or colorectal cancer. 66 This paralleled an increased fecal pH (adj p = 0.00016; Figure 2 D).…”

“… 85 Supporting this notion, observations in Caenorhabditis elegans already established how the host gut microbiota could shape the evolutionary trajectory of its host toward tolerance to pathogens and the resulting adaptive response of the pathogen to microbial agents. 86 Analogous reactions against a system as diverse as that found in horses 52 might, in turn, have had a significant role in the diversification of cyathostomin species.…”

“…Third, horses are hindgut fermenters, e.g., most microbial activities occur in the cecum and large colon, the predilection site for these endoparasites. Therefore, cyathostomins are in close contact with their host hindgut microbiome, 50 , 51 , 52 which spans 5,000 genera from 95 phyla. 52 …”

“…Therefore, cyathostomins are in close contact with their host hindgut microbiome, 50 , 51 , 52 which spans 5,000 genera from 95 phyla. 52 …”

Comparison of two molecular barcodes for the study of equine strongylid communities with amplicon sequencing

“…To overcome the described challenges owing to barcode properties, metagenomic shotgun sequencing on DNA extracted from faeces could resolve the horse gut biodiversity in a single-pot experiment. While gut microbial gene catalogues have been built recently ( Mach et al, 2022 ; Ang et al, 2022 ), the genomic resources for equine strongylids remain restricted to a few mitochondrial genomes that span the Coronocyclus ( Yang et al, 2020 ), Cyathostomum ( Wang et al, 2020 ), Cylicocyclus ( Gao et al, 2017b ), Cylicostephanus ( Gao et al, 2020 ), and Triodontophorus ( Gao et al, 2017a ) genera, and a single heavily fragmented genome assembly for C. goldi ( International Helminth Genomes, 2019 ).…”