Re-examining chemically defined liquid diets through the lens of the microbiome.

Trends in nutritional science are rapidly shifting as information regarding the value of eating unprocessed foods and its salutary effect on the human microbiome emerge. Unravelling the evolution and ecology by which humans have harboured a microbiome that participates in every facet of health and disease is daunting. Most strikingly, the host habitat has sought out naturally occurring foodstuff that can fulfil its own metabolic needs and also the needs of its microbiota, each of which remain inexorably connected to one another. With the introduction of modern medicine and complexities of critical care, came the assumption that the best way to feed a critically ill patient is by delivering fibre-free chemically defined sterile liquid foods (that is, total enteral nutrition). In this Perspective, we uncover the potential flaws in this assumption and discuss how emerging technology in microbiome sciences might inform the best method of feeding malnourished and critically ill patients.

Early History of Home Parenteral Nutrition: From Hospital to Home.

Technologic advances in the past century have led to the ability to safely deliver parenteral nutrition (PN) to hospitalized patients. Key breakthroughs included the development of saline and glucose infusions, infusion pumps, macronutrients (lipids, dextrose, and amino acids), and central venous catheters. In the 1960s, centrally delivered PN was performed in short-term hospitalized patients by Lincoln James Lawson (North Staffordshire Royal Infirmatory, United Kingdom) and long-term patients by Stanley Dudrick (University of Pennsylvania, United States). These early studies showed that a system was needed that would allow patients with intestinal failure to be discharged from the hospital and receive home PN (HPN). In the late 1960s and early 1970s, Belding Scribner, Maurice Shils, Khursheed Jeejeebhoy, Marvin Ament, Dudrick, and their teams discharged patients from the hospital who then self-administered HPN. Shortly after these early cases of HPN, multidisciplinary centers were established first in North America, and later in Europe, to manage these complex cases. The current article describes the patients treated by these early HPN pioneers, in addition to subsequent case series reported by them and others.

The Development of Total Parenteral Nutrition.

The first patient to receive complete nourishment of a patient by intravenous infusion independent of the alimentary tract was an infant girl born with near-total small bowel atresia. Total parenteral nutrition, the intravenous infusion of nutrients, has been attempted since Harvey's description of the circulatory system in the early 17th century. The modern era of parenteral nutrition began in the early 20th century, when infusions of glucose, plasma, and emulsified fat into humans proved feasible. Robert Elman, working in the 1930s and 1940s, demonstrated that carefully prepared protein hydrolysates could be safely infused intravenously and incorporated by the body. Stanley Dudrick and Douglas Wilmore, surgeon researchers at the University of Pennsylvania, worked through the many details of preparation, administration, and clinical monitoring in beagle puppies before testing them on adult patients malnourished from a variety of surgical complications and gastrointestinal conditions. They applied their techniques and formulations on a newborn wasting away from congenital absence of the small bowel, the baby growing and developing for several months while being nourished completely by total parenteral nutrition. Their techniques, inspired by patients with progressive malnutrition from devastating intestinal conditions and malformations, form the basis of the practice of intravenous nutrition practiced today.

[From the advent of total parenteral nutrition to the first successful pediatric intestinal graft in France]. / De l'introduction en France de la nutrition parentérale totale au premier succès de la transplantation intestinale chez l'enfant.

In his opening remarks to Academy of Medicine meeting devoted to Chronic Intestinal Failure and Transplantation on 7 February 2012, Bernard Launois recalled that the first successful intestinal transplantation worldwide was performed in 1987, in France, at Hôpital Necker-Enfants-Malades in Paris. Having had the pleasure of leading this great adventure, and being modestly (and almost by accident) its initiator, Denys Pellerin recalls the circumstances, the difficulties and the vicissitudes of the successive phases. The early hopes and successes of parenteral nutrition in the management of long-term short-bowel syndrome were followed by setbacks and a growing realization of the limits of this approach. Intestinal transplantation was the only way out of this impasse. Uninterrupted research conducted simultaneously in the clinic and on piglets, drawing on the expertise of multiple teams grouped together at Necker-Enfants-Malades, would ultimately lead, after 18 years of intense efforts, to a fragile but encouraging success on 21 March 1987, unanimously recognized as the first-ever successful pediatric intestinal transplant.

Total parenteral nutrition and cancer: from the beginning.

The early development of total parenteral nutrition and its evolution as an adjunct to the nutritional, metabolic, and antineoplastic therapy of cancer patients is described. Examples related to the sine wave of responses to new data and discovery are placed in context to understand better past, present, and how and where to proceed in the future to achieve optimal results from multimodal comprehensive management of patients with malignancies. Practical and philosophic thoughts are proffered to justify continued, intensified, logical, controlled clinical studies directed toward establishing the most rational, safe, and effective use of total parenteral nutrition in treating patients with cancer.

Nutritional support: we have failed in our ability to support patients with sepsis and cancer.

Despite the success of both parenteral and enteral nutrition in supporting patients who cannot eat, patients with either sepsis or cancer cannot be adequately supported. A proposed mechanism by which aerobic glycolysis leads to a shortage of energy production in the liver is discussed. According to this hypothesis, the proximity of sodium-potassium ATPase and glycogen, its fuel source, leads to the continuation of gluconeogenesis with continued proteolysis and muscle wasting. Myostatin and lipokine, newly discovered factors, may also play a role.

Historical highlights of the development of total parenteral nutrition.

The events and discoveries thought to be the most significant prerequisites to the development of total parenteral nutrition (TPN) dating back to the early 17th century are chronicled. A more detailed description and discussion of the subsequent early modern highlights of the basic and clinical research beginning in the mid-20th century and the advances culminating in the first demonstration of the feasibility and practicality of TPN, and its successful, safe and efficacious applications clinically, are presented. Some of the reasoning, insights, and philosophy of a pioneer clinician-scientist in the field are shared with readers.

History of parenteral nutrition.

The concept of feeding patients entirely parenterally by injecting nutrient substances or fluids intravenously was advocated and attempted long before the successful practical development of total parenteral nutrition (TPN) four decades ago. Realization of this 400 year old seemingly fanciful dream initially required centuries of fundamental investigation coupled with basic technological advances and judicious clinical applications. Most clinicians in the 1950's were aware of the negative impact of starvation on morbidity, mortality, and outcomes, but only few understood the necessity for providing adequate nutritional support to malnourished patients if optimal clinical results were to be achieved. The prevailing dogma in the 1960's was that, "Feeding entirely by vein is impossible; even if it were possible, it would be impractical; and even if it were practical, it would be unaffordable." Major challenges to the development of TPN included: (1) formulate complete parenteral nutrient solutions (did not exist), (2) concentrate substrate components to 5-6 times isotonicity without precipitation (not easily done), (3) demonstrate utility and safety of long-term central venous catheterization (not looked upon with favor by the medical hierarchy), (4) demonstrate efficacy and safety of long-term infusion of hypertonic nutrient solutions (contrary to clinical practices at the time), (5) maintain asepsis and antisepsis throughout solution preparation and delivery (required a major culture change), and (6) anticipate, avoid, and correct metabolic imbalances or derangements (a monumental challenge and undertaking). This presentation recounts approaches to, and solution of, some of the daunting problems as really occurred in a comprehensive, concise and candid history of parenteral nutrition.

The impact of nursing practice on the history and effectiveness of total parenteral nutrition.

Nutrition support nursing grew out of the development of total parenteral nutrition in the late 1960s. Nurses contributed to the development of safe and effective delivery of parenteral nutrition and continue to serve on nutrition and metabolic teams in a variety of ways. Research demonstrating the positive effect of the nurse and the team are presented here, along with the history, evolution, and current state of nutrition support nursing.

Early developments and clinical applications of total parenteral nutrition.

BACKGROUND: This article recounts the conditions and status of surgical nutrition support in the 1960s and the antecedent basic and clinical investigational work leading to the development of a practical and efficacious method of adequate nourishment entirely by vein in Beagle puppies; describes the subsequent clinical application of the knowledge, techniques, and technology to the first successful long-term total parenteral nutrition (TPN) support of critically ill pediatric and adult patients; and admonishes nutritionists of all backgrounds that some need for parenteral nutrition will likely always exist and that it is incumbent upon everyone to continue endeavors to advance the germinal methodology to perfection. METHODS: The relevant indications, limitations, hindrances, motivational factors, and studies regarding the development of TPN are reviewed, and the fundamental investigational work culminating in the first successful growth and development of Beagle puppies and a human infant fed entirely by vein are described firsthand. The details of the orderly and logical scientific development of the principles and components of the techniques in animals, infants, and adults are related. RESULTS: Knowledge, techniques, and technologic constituents of the first successful long-term TPN system were developed in the basic biochemical and animal laboratories initially in 6 puppies and subsequently adapted clinically for the efficacious long-term i.v. support of 6 critically ill surgical adult patients and a newborn infant before its widespread clinical application. CONCLUSIONS: Long-term TPN was inaugurated successfully as a safe and effective i.v. feeding technique nearly 4 decades ago. However, basic and clinical investigations must continue to be encouraged, supported, and carried out in the quest to perfect the current rudimentary technology, methodology, and outcomes.

Feeding the premature infant in the 20th century.

This article reviews the historical development of feeding the premature infant in the 20th century. It describes the early work determining the energy requirements of the preterm infant, the evolution of the use of human milk and its fortification for these infants, the development of special formulas for very-low-birth-weight infants and the various techniques/methods utilized including total parenteral nutrition.