Enteral nutrition rapidly reverses total parenteral nutrition-induced impairment of hepatic immunity in a murine model

Role of nutrition in gastroenterological surgery

Nutrition plays important roles in recovery after gastroenterological surgery. Severe surgical stress increases muscle breakdown and lipolysis, thereby accelerating wound healing and enhancing host defense against microbes. Malnourished patients have insufficient amounts of muscle and body fat. Therefore, they may not appropriately respond to surgical stress. Perioperative nutritional therapy maintaining nutritional status reduces postoperative complications and accelerates recovery after surgery, particularly for malnourished patients. In addition, perioperative oral or enteral nutrition is now recommended for preserving host defense mechanisms against microbes. Lack of enteral nutrition impairs gut and hepatic immunity, systemic mucosal defense and peritoneal host defense, even when nutrient amounts supplied by parenteral nutrition are adequate. Thus, surgeons should avoid no oral or enteral nutrition periods. Supplemental administration of specific nutrients such as glutamine, arginine and ω-3 fatty acids is termed "immunonutrition", and is expected to reduce the morbidity of infectious complications and length of hospital stay. Nutritional therapy is important even after discharge to maintain body weight and compensate for abnormalities in the digestion and absorption of nutrients. Understanding the significance of nutrition in gastroenterological patients leads to better outcomes.

Effects of two kinds of enteral nutrition preparations on liver regeneration and function in mice after partial hepatectomy

AIM: To investigate the effects of two kinds of enteral nutrition preparations on liver regeneration and function in mice after partial hepatectomy (PH).

METHODS: A mouse model of oral enteral nutrition (EN) after 70%PH was used in this study. Seventy-two male ICR mice were randomly divided into a PH control group (routine diet after PH), a TP-MCT group (EN with TP-MCT after PH) and a SP group (EN with Peptisorb after PH). Serum samples and liver tissue specimens were collected 1, 3 and 7 d after PH. Serum samples were used to measure the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), albumin, interleukin-6 (IL-6) and IL-10. The liver tissue specimens were used to measure the proliferation of hepatocytes and the morphology of liver tissue by immunohistostaining and HE staining.

RESULTS: In comparison with the PH control group, serum levels of ALT and AST on days 1, 3 and 7 decreased significantly in the TP-MCT group and SP group (P < 0.05 for all). Compared with the PH control group, the level of IL-6 on day 1 decreased significantly in the TP-MCT group and SP group, but the level of IL-10 increased significantly in the TP-MCT group and SP group (P < 0.05 for all). Liver regeneration was enhanced significantly on days 1, 3 and 7 in the TP-MCT group and SP group, especially in the SP group.

CONCLUSION: Enteral nutrition can well protect mouse liver function and promote liver regeneration after PH, with SP (Peptisorb) having a better effect.

Advantages of enteral nutrition over parenteral nutrition

It is a strong and commonly held belief among nutrition clinicians that enteral nutrition is preferable to parenteral nutrition. We provide a narrative review of more recent studies and technical reviews comparing enteral nutrition with parenteral nutrition. Despite significant weaknesses in the existing data, current literature continues to support the use of enteral nutrition in patients requiring nutrition support, over parenteral nutrition.

Enteral and parenteral nutrition in the perioperative period: state of the art

Nutritional support of surgical and critically ill patients has undergone significant advances since 1936 when Studley demonstrated a direct relationship between pre-operative weight loss and operative mortality. The advent of total parenteral nutrition followed by the extraordinary progress in parenteral and enteral feedings, in addition to the increased knowledge of cellular biology and biochemistry, have allowed clinicians to treat malnutrition and improve surgical patient’s outcomes. We reviewed the literature for the current status of perioperative nutrition comparing parenteral nutrition with enteral nutrition. In a surgical patient with established malnutrition, nutritional support should begin at least 7–10 days prior to surgery. Those patients in whom eating is not anticipated beyond the first five days following surgery should receive the benefits of early enteral or parenteral feeding depending on whether the gut can be used. Compared to parenteral nutrition, enteral nutrition is associated with fewer complications, a decrease in the length of hospital stay, and a favorable cost-benefit analysis. In addition, many patients may benefit from newer enteral formulations such as Immunonutrition as well as disease-specific formulations.

Nutrition and gut immunity

The human intestine contains huge amounts of nonpathologic bacteria surviving in an environment that is beneficial to both the host and the bacterial populations. When short pauses in oral intake occur with minimal alterations in the mucosa-microbial interface, critical illness, with its attendant acidosis, prolonged gastrointestinal tract starvation, exogenous antibiotics, and breakdown in mucosal defenses, renders the host vulnerable to bacterial challenge and also threatens the survival of the bacteria. This review examines the altered innate and adaptive immunologic host defenses that occur as a result of altered oral or enteral intake and/or injury.