Three novel strains of Gram-stain-negative, obligately anaerobic, spore-forming straight or slightly curved rods with pointed ends occurring singly or in pairs were isolated from the faeces of healthy human children. The strains were characterized by mesophilic fermentative metabolism and production of acetate, ethanol and H₂ as the end metabolic products. Strains ASD3451 and ASD5720^T were motile, fermented lactose and raffinose, and weakly fermented maltose. Strain ASD4241^T was non-motile and did not ferment the carbohydrates listed above but fermented starch. Strains ASD3451 and ASD5720^T shared average nucleotide identity higher than 98.5 % with each other, while ASD4241^T had only 88.5-89 % identity to them. Based on phylogenetic and chemotaxonomic analyses, we propose Diplocloster agilis gen. nov., sp. nov. (ASD5720^T=JCM 34353^T=VKM B-3497^T) and Diplocloster modestus sp. nov. (ASD4241^T=JCM 34351^T=VKM B-3498^T) within the family Lachnospiraceae .