faecalibacillus faecalibacillus faecalibacillus is a gram-positive, obligately anaerobic long-rod-shaped and non-spore-forming genus from the family of erysipelotrichidae with one known species (faecalibacillus intestinalis). faecalibacillus intestinalis has been isolated from human faeces. faecalibacillus scientific classification domain: bacteria phylum: bacillota class: erysipelotrichia order: erysipelotrichales family: erysipelotrichaceae genus: faecalibacillusseo et al. 2019 type species faecalibacillus intestinalisseo et al. 2019 species f. faecis f. intestinalis