title: The clinical significance of gastrointestinal changes with aging.
abstract: OBJECTIVE
  With the graying of the world's population, there is an increased interest in the physiological effects of aging. This review examines the physiological changes of the gut with aging and their clinical significance.
  
  
  RESULTS
  Changes with aging in the gastrointestinal tract are variable, but in some cases they are responsible for a variety of symptoms. Thus, alterations in taste and smell, gastric motility, intestinal overgrowth and changes in gastrointestinal hormone release are the basis of the physiological anorexia of aging. Alterations in swallowing lead to silent aspiration. Changes in gastric emptying play a role in postprandial hypotension. Changes in gastrointestinal function can lead to constipation and fecal incontinence. Weakening of the colonic muscular wall produces diverticula. Achlorhydria is associated with malabsorption of some forms of iron and calcium. Vitamin D malabsorption aggravates the hypovitaminosis D that is so common in older persons. Changes in probiotics can lead to diarrhea and altered immune system. In the liver, aging is associated with delayed drug metabolism.
  
  
  CONCLUSIONS
  Changes in the physiology of the gut play a role in the anorexia of aging, aspiration pneumonia, postprandial hypotension, constipation and fecal incontinence.
authors.affiliation: Division of Geriatric Medicine, Saint Louis University, USA bGRECC, VA Medical Center, St. Louis, Missouri, USA.
authors.forename: Asif
authors.initials: A
authors.lastname: Bhutto
authors.forename: John E
authors.initials: JE
authors.lastname: Morley
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D000855:Anorexia / Q000503:physiopathology; D003679:Deglutition / Q000502:physiology; D017615:Enteric Nervous System / Q000502:physiology; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology; D041981:Gastrointestinal Tract / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D008297:Male; D019936:Probiotics / Q000627:therapeutic use; D012677:Sensation / Q000502:physiology