Sex-Speciﬁc Biology of the Gastrointestinal Tract
As is the case with every system of the body, the research of the last 15 years has documented the sexual dimorphism of the normal function of the digestive system. From salivary composition and ﬂow rate to the molecular biology of the P450 system that metabolizes drugs, the digestive system has sex-speciﬁc, unique characteristics. However, as is the case with all information about the sexual dimorphism of normal human physiology and the pathophysiology of disease, information about the impact of biological sex on gastrointestinal function and on sex-speciﬁc nutritional requirements is often rudimentary. Much of it consists of observational data and, less frequently, original investigations about the impact of biological sex on nutritional requirements. Many isolated observations about sexspeciﬁc gastrointestinal function are reported almost incidentally and scattered throughout the literature. Recently, however, systematic overviews of what is known about the sex-speciﬁc biology of the gastrointestinal tract and the experience of gastrointestinal illnesses have begun to appear in the literature [1,2]. This chapter summarizes some of that information as they may help in the understanding of sex differences in nutrient requirements and in the prevention and management of some chronic diseases.