Pan-hypoileism: an endocrine disease

Over the past four decades, the gastrointestinal tract has been increasingly recognized as a major endocrine organ. Each of its segments plays a distinct role in digestion, absorption, inter-organ signaling, and metabolic regulation, and each category of food requires a specific physiological response. Consequently, carnivores, herbivores, and omnivores have adapted their digestive systems to meet the demands of their typical diets. Signals arising from the digestive tract influence nearly all other organs and their metabolic activities. Gluconeogenesis, insulin resistance, energy expenditure, the hunger-satiety cycle, glucose effectiveness, lipid clearance, and gastric emptying are examples of metabolic processes profoundly regulated by the gut. Emerging evidence now suggests that the distal part of the human small intestine, the ileum, is progressively failing to perform its full range of functions, including its endocrine roles, in a substantial proportion of the population. This phenomenon may constitute a growing pandemic. The term pan-hypoileism has not previously been used. In this review, we explore why this term deserves recognition as an endocrine disease. Clarifying this condition may be important for both patients and physicians.