Understanding digestive functions and the role of microorganisms in the prevention of gastrointestinal and systemic diseases may be a strategy for preventing intestinal dysbiosis during critical periods of animal rearing, strengthening the immune system and reducing herd mortality. The aim of the study was to determine the effect of the addition of fermented rapeseed meal (FRSM) to the diet of rabbits on the composition of the bacterial microbiota of the caecal contents. The experiment was conducted using 40 35-day-old rabbits (