Nutr. Hosp. (2001) XVI (6) 239-256 ISSN 0212-1611 • CODEN NUHOEQ S.V.R. 318 Revisión Use of Pro-, Pre- and Synbiotics in the ICU - Future options S. Bengmark*, A. García de Lorenzo** y J. M. Culebras*** * Departamento de Cirugía, Universidad de Lund, Suecia. ** Servicio de Cuidados Intensivos, Hospital Universitario La Paz, Madrid. *** Servicio de Cirugía II, Hospital de León, León, España. Abstract EL USO DE PRO, PRE Y SIMBIÓTICOS EN CUIDADOS INTENSIVOS: POSIBILIDADES Although the word synbiotics was coined to describe FUTURAS the combined action of pre- and probiotics, the ability to, like antibiotics, control infection, the term is now in- Resumen creasingly used in a wider sense, as a name for all the substances released by microbial fermentation in the lo- Aunque la palabra simbióticos fue acuñada para des- wer gut. One obvious reason is that most of the substan- cribir la acción combinada de pre y probióticos de con- ces released seem to influence the immune defense, in- trolar la infección, como los antibióticos, el término se crease resistance to disease, and, most important, utiliza cada vez en sentido más amplio, incluyendo todas prevent complications to surgery such as infections and las sustancias que son liberadas en el intestino distal por thrombosis. Protection layer of lactobacillus does not fermentación bacteriana. Una razón obvia es que la ma- exist only on the GI tract mucosa, it is important at all yor parte de esas sustancias parece tener influencia en exterior body surfaces including those of the eye, the no- los mecanismos de defensa, en la resistencia a la infec- se, the mouth, the respiratory tract, the vagina, not to ción y, lo que es más importante, en la prevención de forget the skin. It is clearly reduced at all sites when the complicaciones quirúrgicas tales como infecciones y patient is in the settings of ICU. trombosis. La capa protectora de lactobacillus no está Each human being has his/her own unique microbial presente únicamente en el tracto gastrointestinal. Es im- collection, especially of strains of Bifidobacterium and portante también en las superficies externas del organis- Lactobacillus, and it should be possible to identify an in- mo, el ojo, la nariz, la boca y el tracto digestivo, la vagi- dividual on the basis of his/her personal intestinal mi- na y la piel. Se reduce claramente en todos estos lugares croflora. cuando el paciente se encuentra en la unidad de cuida- The flora seems always to be significantly reduced in dos intensivos. the sick, especially in connection with severe disease, ca- Cada ser humano tiene su colección única de micro- re in ICU, and in patients with little food intake or on bios, con cepas específicas de bifidobacteria y lactobaci- parenteral nutrition. Supply of both pre- and probiotics lli, y sería posible identificar a los individuos a través de can modify functions such as appetite, sleep, mood and su microflora intestinal personal. circadian rhythm, and this most likely through metabo- La flora parece reducirse siempre de manera signi- lites produced by microbial fermentation in the gut. ficativa en los enfermos, especialmente en enfermeda- Supply of lactic acid bacteria (LAB) can also signifi- des graves, en cuidados intensivos, en pacientes con in- cantly reduce serum levels of a variety of toxins such as gesta alimentaria reducida y en los sometidos a endotoxin. nutrición parenteral. El suplemento de pre y probióti- An umbrella of supplemented probiotics could provi- cos puede modificar el apetito, el sueño, el estado aní- de to the patients with liver cirrhosis a tool to reduce mico y el ritmo circadiano, probablemente a través de spetic manifestations and the incidence of bleeding. LAB metabolitos producidos por la fermentación microbia- are effective in controlling diarrhea of both bacterial na en el intestino. La administración de bacterias del and viral origin. A series of experimental studies and se- ácido láctico también reduce de manera significativa los niveles séricos de una variedad de toxinas, como la endotoxina. Correspondencia: Abelardo García de Lorenzo. Un paraguas de suplemento de probióticos podría fa- Formación Médica Continuada. cilitar a pacientes con cirrosis una herramienta para Hospital Universitario La Paz. protegerse frente a manifestaciones sépticas y a hemo- P.º Castellana, 261 Madrid, España rragia. Las bacterias del ácido láctico son efectivas en [email protected] controlar la diarrea tanto de origen bacteriano como vi- Recibido: 5-V-2001. ral. Una serie de experimentos clínicos no controlados Aceptado: 12-VIII-2001. 239 veral uncontrolled clinical studies support the idea of sugieren que los probióticos podrían ser de utilidad en la using probiotics in patients with IBD. Ecoimmunonutri- enfermedad inflamatoria intestinal. La ecoinmunonutri- tion with pre- pro- and synbiotics offer to be suitable to- ción con pre-, pro y simbióticos parece ser un arma tera- ols in the new millenium. péutica adecuada en el futuro. (Nutr Hosp 2001, 16:239-256) (Nutr Hosp 2001, 16:239-256) Key words: Econutrition. Symbiotics. Critical Care. Palabras clave: Econutrición. Simbióticos. Paciente Prebiotics. Probiotics. Crítico. Prebióticos. Probióticos. Introduction usually referred to as “colonic foods”. It is recom- mended that at least ten per cent of the total calorie in- The large intestine was not long ago regarded as an take should be of this type, a goal difficult to meet in organ with almost only one function - to beabsorb wa- the very sick patients. As prebitic fibers are low-calo- ter and electrolytes. It has not been realized for long, ric, at leas one fourth of the vood eaten under healthy at least not among clinicians, that the coon is a highly conditions is recommended be of the type “food desti- active metabolic organ, in which numerous metabolic ned for the colon”, e.g. food ingredients that not are processes take place and almost uncountable nutrients broken down by gastrointestinal juice enzymes and are released and absorbed. Here bacterial enzymes of absorbed in the upper small intestine. In the past it probiotic bacteria metabolize prebiotics (various fruit was usually regarded as ore or less impossible to pro- and vegetable fibers, but also gastrointestinal secre- vide colonic foods to patients in the ICU, a view, tions and apoptotic cell) and countless numbers of which in recent years has been revised. products are released and absorbed - products increa- singly referred to as synbiotics. Fibers are prebiotics Today colon is known as a metabolic organ with eventually more and also more complex functions Research regarding various probiotics have in re- than the rest of the gastrointestinal tract, where che- cent years explosed and information about the various mical processes are promoted by enzymes produced probiotic bacteria is fast increasing. Prebiotics are as by bacterial instead of eukaryotic cells. An indication importante, as availability and content of various fi- of the complexity of the metabolic activities in the lar- bers limits the production of symbiotic compounds ge intestine is the information that the colonic “micro- produced. bial organ” contains about 300 000 genes, to be com- Fibers are carbohydrates derived from plant cell pared to the about 65 000 genes in the rest of the walls, and dietary fibers are usually classified into th- human body. Numerous substances, several hundred ree groups: soluble fibers such as pectins and various thousand if not millions, are produced, released and gums, insoluble fibers such as cellulose and mixed ty- absorbed at the level of the lower small and the large pe fibers such as brans. The most important characte- intestine. Among these are various fatty acids, espe- ristic for them all is that they are resistant to hydroly- cially short chain fatty acdis (SCFA’s), carbohydra- sis by human alimentary tact enzymes, which make tes, amino acids, polyamides, vitamins, antioxidants, some of them ideal substrate for microbial fermenta- phytoestrogens, and coagulation and growth factors. tion in the lower GI tract. soluble fibers (prebiotics) Only of polyphenols such as flavonoids exist more constitute an important source for bacterial fermenta- than four thousand and of carotenoids about six hun- tion and microbial production of nutrients, antioxi- dred. dants, vitamins, and growth and other important fac- Although the word synbiotics was coined to descri- tors. This far, the main interest has focused on the be the combined action of pre- and probiotics, the abi- production of various short chain fatty acids (SCFAs) lity to like antibiotics control infection, the term is and fermentation by-products such as hydrogen, met- now increasingly used in a wide sense, as a name for hane and carbon dioxide. But the content of other nu- all the substances released by microbial fermentation trients; various bioactive amino acids, polyamins, an- in the lower gut. One obvious reason is that most of tioxidants and various growth factors etc are equally the substances released seem to influence the inmune important.1-5 defense, increase resistance to disease, and, most im- Prebiotic fibers are slow carbohydrates, which ha- portant, prevent complications to surgery such as in- ve a strong influence glucose and fat metabolism, fections and thrombosis. and cause decrease in postprandial glycemia, reduc- The food ingredients (fibers, complex proteins, tion in the concentration of free fatty acdis and in se- etc.), which mainly unchanged reach the colon, are rum cholesterol levels.6-7 An increase in proliferation 240 Nutr. Hosp. (2001) 16 (6) 239-256 S. Bengmark y cols. Table I Betaglucans Probiotics-molecular effects Another most interesting group of fibers are the be- — Stimulates sIgA production. taglucans, a group of unique water soluble fibers of- — Inhibits IgE production. ten extracted from oat, which contains as much as up 15 — Modulates Th1/Th2 response. to 17% of betaglucans. This gum fiber compares fa- — Modulates cytokine response. vorably with other high viscosity polysaccharides — Stimulates NO production.