From Ancient Enemas to Tube Feeding, I: History, Administration, and Nutritional Composition of Commercial Versus Food-Based Formulas in Critical Illness

During critical illness, tube feedings are used to provide vital nutrition for patients unable to obtain adequate oral intake. Part I of this 2-part review article series examines the history, delivery, and content of enteral formulas in the intensive care unit. Food-based tube feedings date back to ancient times when ill patients received nutrition via enemas composed of ingredients such as barley, eggs, and wine. Since the mid-1900s, the landscape has been dominated by commercially prepared ("commercial" or "conventional") formulas-synthetic blends composed of vitamins and minerals mixed with processed proteins, carbohydrates, fats, thickening agents, and shelf-life extenders such as sodium caseinate, maltodextrin, canola oil, and corn syrup. In response to increasing interest in whole foods and their role in illness recovery, food-based formulas have gained popularity as an alternative, supported by the emergence of plant- and food-based blends, growing scientific attention, and inclusion in hospital formularies. Part I provides an overview of the historical evolution of enteral feeding practices, methods of administration, and the nutritional content of commercial versus food-based formulas. In part II, clinical outcomes and future directions will be evaluated. Together, this 2-part series aims to inform prescribing practices and promote patient-centered nutrition strategies in critical care.