The genus Lachnoanaerobaculum comprises obligately anaerobic, Gram-stain-positive chemoorganotrophic, saccharolytic, and nonproteolytic bacilli. Cells are spore forming, rod shaped, and filamentous, 5 to greater than 20 μm in length, some cells with curving and swelling. All species of the genus grow with glucose as the sole carbon source. All species produce H2S, NH3, butyric acid, acetic acid, and lactic acid as metabolic end products. The predominant cellular fatty acids are C14:0, C16:0, and C18:1 ω7c DMA. The G + C contents of genomic DNA of the species are 35.0–37.8 mol%. Phylogenetic relationships of the species of Lachnoanaerobaculum, based on comparative 16S rRNA gene sequence analyses, indicate that they cluster within the phylum Firmicutes, within the family Lachnospiraceae, and exhibit a clear delineation to the other genera of the family, with a relatively close relationship to Johnsonella species. The first described strain of Lachnoanaerobaculum umeaense, the type species of the genus, was isolated from the jejunal mucosa of a child with coeliac disease. Strains of the species of Lachnoanaerobaculum are typically found in intestinal microbiota and oral microbiota of the human microbiome, isolated from the human gut, saliva, blood, amniotic fluid, and, predominantly, from the oral cavity.