This dataset contains the following:
1)	Biom table summary “biom_table_summary.txt”
2)	Master run log in QIIME version: 1.9.1 “log_20170803151842.txt”
3)	Filtered BIOM table (minimum sequence count: 5000) “table_even5000.biom.gz”
4)	Rarefied BIOM table (sampling depth: 5000) “table_mc5000.biom.gz”
5)	OTUs relative abundance at phylum taxonomic level for each sample in .biom and .xlsx formats “table_mc5000_sorted_L2.biom”, "table_mc5000_sorted_L2.xlsx" 
6)	OTUs relative abundance at class taxonomic level for each sample in .biom and .xlsx formats  “table_mc5000_sorted_L3.biom”, "table_mc5000_sorted_L3.xlsx" 
7)	OTUs relative abundance at class taxonomic level for each sample in .biom and .xlsx formats “table_mc5000_sorted_L4.biom”, "table_mc5000_sorted_L4.xlsx" 
8)	OTUs relative abundance at family taxonomic level for each sample in .biom and .xlsx formats “table_mc5000_sorted_L5.biom”, "table_mc5000_sorted_L5.xlsx" 
9)	OTUs relative abundance at genus taxonomic level for each sample in .biom and .xlsx formats “table_mc5000_sorted_L6.biom”, "table_mc5000_sorted_L6.xlsx" 

Abbreviations used:
OTUs - operational taxonomic units
VEQ - VistaEQ (name of the product investigated)
P - pony
CP - collection period
k__ - kingdom
p__ - phylum
c__ - class
o__ - order
f__ - family
g__ - genus

Summary of the study 

The aim of the study was to determine the effect of a VistaEQ product containing 4% live yeast Saccharomyces cerevisiae strain Y1242 on faecal microbial populations when supplemented to high-starch and high-fibre diets using Illumina next generation sequencing of the V3-V4 region of the 16S rRNA gene. Seven mature Welsh ponies were used in a complete randomised 4 x 4 Latin square design consisting of 4 x 19-day periods. After DNA extractions from faeces and library preparation, alfa-diversity and Least disciminate analysis effect size (LEfSe) analysis were performed using 16S metagenomics pipeline in QIIME v1.9.0. Differences between the groups were considered significant when linear discriminant analysis (LDA) score >2. The  study results showed that the Saccharomyces cerevisiae was able to induce positive changes in the equine microbiota when supplemented to a high-fibre diet: it increased relative abundance (RA) of members of Lachnospiraceae and Dehalobacteriaceae families, associated with a healthy core microbiome. Moreover, yeast supplementation increased the counts of fibrolytic bacteria (Ruminococcus) when fed with a high-fibre diet and reduced counts of lactate producing bacteria (Streptococcus) when a high-starch diet was fed. In addition, yeast increased 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.