Clostridium butyricum: a promising probiotic confers positive health benefits in aquatic animals

Abstract Clostridium butyricum is a bacterium of rod shape, strictly anaerobic, Gram‐positive and form spores. Short‐chain fatty acids, biofuel compounds and precursors of biomaterials (H 2 , butanol and 1,3‐propanediol) are produced by C. butyricum during the fermentation of carbohydrates and sugars. In humans and animals, although C. butyricum has been found to be associated with botulism in infant and necrotising enterocolitis in preterm neonates, some strains have been demonstrated to be beneficial as probiotics. In aquatic animals, the application of C. butyricum as a probiotic has been commonly considered. In this review, we described and documented what we knew about the isolation, identification, phenotypic and biochemical characteristics, safety, pathogenicity and the mechanisms of action of C. butyricum in the gastrointestinal tract of aquatic animals. The evidence on the roles that C. butyricum plays in improving growth performance, digestibility, survival rate, immune response, disease resistance and the structure of intestinal tract, as well as the modulation of gut commensal microbiota and metabolic disorders in aquatic animals, is summarised. Albeit the probiotic C. butyricum has been applied in aquaculture, and further research, such as the inter‐relationships between the probiotic and the immune system of the host and the possible application of C. butyricum as an alternative to antibiotic substitution for the prevention and treatment of diseases, is required for future detailed studies.