The gut microbiome has emerged as a critical regulator of host lipid metabolism, significantly influencing intramuscular fat (IMF) deposition and overall meat quality. This review synthesizes current evidence linking gut microbial composition with marbling in livestock, especially in pigs, highlighting the concept of the gut−adipose axis as a novel target for meat quality enhancement. Recent studies in pigs, ruminants, and poultry indicate that specific microbial communities modulate fat deposition through multiple mechanisms, including enhanced energy harvest via short-chain fatty acids, modulation of inflammatory and endocrine signaling, and alteration of nutrient absorption. Interventions such as microbial supplementation—using probiotics, prebiotics, and synbiotics—may reshape the gut ecosystem to favor lipogenesis, while nutritional strategies, including use of fiber-degrading enzymes and organic acids, further influence microbial fermentation profiles. Evidence from fecal microbiota transplantation and targeted probiotic studies suggests that manipulating the gut microbiome can directly increase IMF and improve meat quality traits in certain contexts. By integrating mechanistic insights and applied strategies, this review offers a promising framework for sustainable and precision-based approaches to enhance marbling in modern livestock production systems.
Zhang et al. (Thu,) studied this question.