Gut health is a multifaceted concept encompassing the physiological state and functional integrity of the gastrointestinal tract, including its complex microbial ecosystem and the interactions therein. As a research field, it investigates the composition, diversity, and metabolic activity of the gut microbiome, the integrity of the intestinal barrier, and the intricate host-microbe interactions that collectively influence nutrient absorption, immune function, metabolic regulation, and neurological signaling, thereby playing a critical role in maintaining physiological homeostasis and contributing to the pathogenesis or prevention of systemic diseases.