The effect of supplementing pony diets with yeast on 2. The faecal microbiome

Abstract

There is a need to develop feeding strategies to prevent the adverse effect of concentrate feeding in high-performance horses fed energy-dense diets aiming to maintain their health and welfare. The objective of this study is to determine the effect of a VistaEQ product containing 4% live yeast Saccharomyces cerevisiae ( S. cerevisiae ), with activity 5 × 108 colony-forming unit/g and fed 2 g/pony per day, on faecal microbial populations when supplemented with high-starch and high-fibre diets using Illumina next generation sequencing of the V3-V4 region of the 16S ribosomal RNA gene. The four treatments were allocated to eight mature Welsh section A pony geldings enrolled in a 4-period × 8 animal crossover design. Each 19-day experimental period consisted of an 18-day adaptation phase and a single collection day, followed by a 7-day wash out period. After DNA extraction from faeces and library preparation, α-diversity and linear discriminant analysis effect size were performed using 16S metagenomics pipeline in Quantitative Insights Into Microbial Ecology ( QIIME™ ) and Galaxy/Hutlab. Differences between the groups were considered significant when linear discriminant analysis score was >2 corresponding to P < 0.05. The present study showed that S. cerevisiae used was able to induce positive changes in the equine microbiota when supplemented to a high-fibre diet: it increased relative abundance (RA) of Lachnospiraceae and Dehalobacteriaceae family members associated with a healthy core microbiome. Yeast supplementation also increased the RA of fibrolytic bacteria (Ruminococcus) when fed with a high-fibre diet and reduced the RA of lactate producing bacteria (Streptococcus) when a high-starch diet was fed. In addition, yeast increased the RA of acetic, succinic acid producing bacterial family (Succinivibrionaceae) and butyrate producing bacterial genus (Roseburia) when fed with high-starch and high-fibre diets, respectively. VistaEQ supplementation to equine diets can be potentially used to prevent acidosis and increase fibre digestibility. It may help to meet the energy requirements of performance horses while maintaining gut health.

The Role of Yeast Saccharomyces cerevisiae in Supporting Gut Health in Horses: An Updated Review on Its Effects on Digestibility and Intestinal and Fecal Microbiota

“…The same results were also confirmed when analyzing the differentially abundant taxa between supplemented and non-supplemented animals; the significant OTUs seemed to be more influenced by the animals themselves rather than by the yeast [ 87 ]. Similar results were also reported by other studies [ 13 , 73 ], which suggest that for an optimal evaluation of the effects of yeasts or any other products on horses’ microbiome, each animal should serve as its own control to avoid biases due to biological variability.…”

“…Focusing on horses receiving a diet with HR concentrations—thus, one that is closer to their natural feeding behavior—only a few studies reported a significant modulation of fibrolytic populations and activity by yeast administration, in line with what was observed in the in vivo digestibility trials. Recently, Garber et al [ 73 ] reported that the supplementation of an HR diet with 50 g/day of a product containing 4% live yeast S. cerevisiae (5 × 10 8 cfu/g) resulted in an increased relative abundance of fibrolytic bacteria in the feces. Specifically, they observed that the Lachnospiraceae family was one of the most abundant families, and they identified the genus Roseburia , which belongs to the same Lachnospiraceae family, as the biomarker of the animals receiving an HR diet supplemented with yeast.…”

“…Several beneficial effects of S. cerevisiae have been observed on amylolytic, lactate-producing, and lactate-utilizing bacteria in horses fed HC diets [ 9 , 43 , 72 , 73 ], while basically no effects have been reported with HR diets [ 13 , 46 ]. Following the addition of yeast in the diet of horses receiving HC diets, several authors reported an increase in lactate-utilizing bacteria in the feces [ 9 , 72 ], in the cecum [ 4 ], and the colon [ 72 ].…”

“…Following the addition of yeast in the diet of horses receiving HC diets, several authors reported an increase in lactate-utilizing bacteria in the feces [ 9 , 72 ], in the cecum [ 4 ], and the colon [ 72 ]. At the same time, a reduction of lactate-producing bacteria ( Streptococcus ) has also been associated with the administration of 50 g/day of a product containing 4% live yeast S. cerevisiae (5 × 10 8 cfu/g) to horses fed an HC diet [ 73 ]. In line with these results, Medina et al [ 43 ] reported a reduction in the lactic acid-utilizing to lactic acid-producing bacteria ratio.…”

Dose-Dependent Effects of Histamine on Growth, Immunity and Intestinal Health in Juvenile Grouper (Epinephelus coioides)

“…in hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂), paralleled with suppression of growth performance. As for horse study, supplementation of Saccharomyces cerevisiae (S. cerevisiae) modulated positively the overall structure of intestinal microbiota with increased relative abundance of Lachnospiraceae (Garber et al, 2020), which is a family of butyrate-producing bacteria (Nicholson et al, 2012;Hamilton et al, 2020). On the other hand, high fat diet resulted in a reduction of the relative abundance of the Bacteroidetes_S24-7_group and Lachnospiraceae in mice, which might be one of the primary etiological mechanisms underlying obesity (Li et al, 2020).…”