Abalone Gut Microbiome Regulators: A Review Synthesizing Gut Physiology, Microorganisms, Diet and the Environment

Abstract

Abalone are economically, ecologically and culturally significant marine molluscs, with both wild and farmed populations under pressure due to intrinsic and extrinsic stressors. Abalone performance and health are centred on a highly specialized digestive system supported by a diverse gut microbiome, which enables nutrient assimilation, polysaccharide digestion, immune regulation and disease resistance. This review consolidates our current understanding of the abalone gut microbiome regulation by examining the interactions among host digestive physiology, microbial diversity and function, dietary influences and environmental conditions. Based on a systematic evaluation of sequencing-based studies published between 2015 and 2025 and spanning 14 abalone species, a shared core gut microbiome was identified, primarily composed of genera including Mycoplasma, Psychrilyobacter and Vibrio. This review also evaluates microbiome-related symbiosis and dysbiosis, with emphasis on how diet and environmental stress reshape microbial functions linked to growth, immunity and disease susceptibility. Finally, current methodological limitations and major knowledge gaps are outlined, particularly the need for mechanistic and multi-omics approaches, standardized sampling and longitudinal surveys. As microbiome research progresses, these insights can be translated into practice, moving abalone aquaculture and fisheries beyond reactive management toward precision strategies that ultimately enhance animal health, productivity and long-term ecological sustainability.