Table 1. Relative abundance of the main intestinal bacterial phyla reported for healthy equines (HE) and intestinal disease equines (IDE).

Study group	HE	IDE	N° of equines evaluated (HE/IDE)	Reference
Donkeys	Firmicutes, Bacteroidetes	Uninformed	5/ 0	Liu et al., 2019
Sport horses	Spirochaetes, Tenericutes, Firmicutes	Uninformed	185/ 0	Mach et al., 2020
Sport horses without or with diarrhea	Bacteoidetes, Verrucomicrobia, Firmicutes	Bacteroidetes, Proteobacterias, Firmicutes	45/ 5	McKinney et al., 2020
Thoroughbred horses without or with colic	Bacteoidetes Firmicutes	Firmicutes Bacteroidetes	24/ 28	Park et al., 2021
Horses managed at pasture	Bacteoidetes, Firmicutes, Spirochaetes	Uninformed	7/ 0	Salem et al., 2018
Sport horses without or with colic	Bacteoidetes Firmicutes, Fibrobacteres	Firmicutes Bacteroidetes, Fibrobacteres	5/ 9	Salem et al., 2019
Horses without or with colic	Bacteoidetes Firmicutes, Fibrobacteres	Firmicutes Bacteroidetes, Fibrobacteres	30/ 17	Stewart et al., 2018
Horses with colic	Uninformed	Firmicutes, Bacteroidetes, Spirochaetes	0/ 17	Stewart et al., 2020
Horses without or with colic	Firmicutes Bacteroidetes, Proteobacteria	Bacteoidetes Firmicutes, Proteobacteria	6/ 10	Costa et al., 2012