[Symbiotics: a new strategy in critically ill patients treatment]. / Simbióticos: una nueva estrategia en el tratamiento de pacientes críticos.

Maintenance of the gut environment is a key factor in determining outcome in the care of critically ill and postoperative patients. It is especially important to maintain both gastrointestinal secretions, full o anti-infectious and anti-inflammatory compounds, and the gut flora. Prebiotics, usually polysaccharides, exhibit strong bio-activity and the ingestion of prebiotics has been shown to reduce the rate of infection and restore health in sick and postoperative patients. Probiotics may have at least five functions, all of great importance to the sick patients: the reduction or elimination of potentially pathogenic micro-organism of various kinds; the reduction or elimination of various toxins, mutagens, carcinogens, etc.; modulation of the innate and adaptive immune defence mechanisms; the promotion of apoptosis; and the release of numerous nutrient, antioxidant, growth, coagulation and other factors necessary for recovery. A combination of pre and probiotics is referred to as "synbiotics". Our experience of synbotic treatment in critically ill patients is limited, but cutting-edge results from studies of severe acute pancreatitis, chronic hepatitis and liver transplantation offer great hope for the future. This is especially importante as pharmaceutical treatment, including the use of antibiotics, has largely failed, and the medical world is in much need of new treatment paradigms.

[Enteral nutrition: past and future]. / Nutrición enteral: pasado y futuro.

Perioperative nutrition has during the last century been transformed from a tool to provide calorie and nitrogen support to a tool to boost the immune system and increase resistance to complications. Despite all progress in medicine and surgery has perioperative morbidity, rate of infections, thrombosis and development of serosal adhesions remained the same as long as can be judged or at least during the last eighty years. Most prone to develop complications are persons above the age of 65 and persons with depressed immunity. About eighty percent of the immune system is localised in the gastrointestinal tract, which offers great opportunities for modulation through enterar nutrition. As the stomach has a tendency to develop postoperative paralysis, tube feeding is often necessary. Andresen demonstrated already in 1918 the advantages of enteral nutrition, which starts already on the table. Mulholland et al and Rhoads and co-workers demonstrated during the 1940s certain advantages of enteral tube feeding. Also works by Alexander, Fischer, Ryan and their co-workers supported the value of early enteral feeding, and suggested enteral feeding as an effective tool to boost the immune system. It was, however, works published in the early nineties by Moore et al and by Kudsk et al, which made surgeons more aware of the advantages of early enteral nutrition. Major surgery is known to have a high rate of complications. Uninterrupted perioperative nutrition, eg nutrition during the night before, during surgery and immediately after offers a strong tool to prevent complications. It is essential that the nutrition provides food also for the colon, e.g. fibres and healthy bacteria (probiotics) to ferment the fibre and boost the immune system.

[Effects of glutamine on antioxidants systems and hepatic detoxification in rats: influence of formulation]. / Influencia de la formulación de la glutamina en sus efectos sobre los sistemas antioxidantes y de destoxificación hepática en la rata.

GOALS: The goal of this study is to assess the effect that supplementing parenteral diets with L-glutamine or with L-alanyl-L-glutamine has on the balance of oxidants/antioxidants in the liver and on detoxification systems mediated by P-450 cytochrome in rats. MATERIAL AND METHODS: Central catheters were inserted in the animals (n = 60) and they were randomly assigned to one of the following groups: a control group (C) with oral feeding and I.V. infusion of saline solution, a total parenteral nutrition group without glutamine (TPN without GLN), a parenteral nutrition group with glutamine supplement (TPN GLN), and a total parenteral nutrition group with a supplement of alanine-glutamine dipeptide (20 g/L) (TPN ALA-GLN). The parenteral nutrition provided was all isocaloric and isonitrogenated, and the infusions were administered at a speed of 2 ml/h over 5 days. RESULTS: In the animals of the group without GLN, the liver concentration of glutathione was reduced while the levels of thiobarbituric acid reaction products (TBARS) increased. Supplementing with either glutamine or alanine-glutamine normalized the levels of glutathione but the TBARS levels only fell in the group with the dipeptide. This effect was parallel to the partial recovery of the antioxidant enzyme activities analyzed. The liver concentrations of P-450 cytochrome, P-450 cytochrome dependent mono-oxygenases and the clearance of antipyrine were not modified by the supplements of glutamine or alanine-glutamine. CONCLUSIONS: Our data suggest a greater protection by alanine-glutamine supplements against the injury produced by free radicals during TPN and the absence of any effect with either glutamine or alanine-glutamine supplements on the oxidative metabolism of the liver.