Metabolic interactions is a concept and research area concerned with the reciprocal influence between distinct biological entities (such as organisms, cells, or cellular compartments) mediated by their respective metabolic activities. This field investigates the mechanisms and consequences of metabolite exchange, competition for resources, and metabolic regulation that link these entities, impacting their individual and collective dynamics, ecological fitness, and cellular functions. Its significance lies in elucidating the complex interdependencies within biological systems, from microbial consortia to host-microbiome relationships and intracellular pathway coordination.