Anaerobutyricum—An Emerging Butyrate-Producing Genus with Potential Relevance to Host Health

Anaerobutyricum is a Gram-positive, obligately anaerobic genus within the family Lachnospiraceae that is widely distributed in the gut microbiota of humans and animals. This genus has attracted increasing attention because of its ability to produce short-chain fatty acids, particularly butyrate, a key microbial metabolite involved in intestinal homeostasis, immune regulation, and host energy metabolism. The genus currently comprises only two validly described species, Anaerobutyricum hallii and Anaerobutyricum soehngenii. Despite this limited taxonomic representation, accumulating evidence has linked variation in Anaerobutyricum abundance to host health and disease. In humans, alterations in Anaerobutyricum abundance have been linked to metabolic, inflammatory, and neurodegenerative disorders. In livestock, especially pigs, limited evidence suggests that this genus may also be associated with growth-related traits, intestinal health, and reproductive performance. In this review, we summarize current knowledge of the taxonomy, physiological characteristics, genomic features, metabolic potential, and major factors influencing the abundance of Anaerobutyricum. We further discuss its reported associations with human health and its possible relevance to animal production, with particular attention to pigs at different developmental stages. Overall, Anaerobutyricum appears to be a promising functional genus; however, most available evidence remains association based rather than causal, livestock studies are still sparse, host interaction mechanisms remain poorly understood, and its utility as a probiotic candidate, biomarker, or microbiome-based intervention target requires further strain-level, mechanistic, and in vivo validation.