Gut is an important organ for communication between the organism and the external environment. It collects nutrients and removes waste, contributing significantly to maintaining the body's homeostasis and physiological functions. The gut contains various cell types and neural signaling molecules. Previous studies have indicated that specific receptors on the intestinal cells are activated by food, allowing for the perception of taste and nutritional components and conveying this information directly or indirectly to the brain. Intestinal perception is ubiquitous in many organisms in nature and conserved among species. Therefore, investigations into intestinal perception have critical implications for understanding the evolution of species and the adaptive mechanisms of organisms in nature. This review aims to provide a brief overview of current research on the molecular and circuit mechanisms underlying the perception of various substances in the gastrointestinal tract, which provides a theoretical basis for future investigations into the roles of the gut-brain axis in the adaptive evolution of individual organisms and the evolution of facilitation in organism-environment symbiosis.