BENGT KLARIN
Lund University and Skåne University Hospital Department of Anaesthesiology and Intensive Care, SE 221 85, Lund, Sweden

Abstract

The balance of intestinal microbiota, which is present in health, can be affected by severe illness and antibiotics. Pathogenic bacteria, which are usually suppressed by the commensal flora, may multiply and can cause complicating secondary infections. Administration of probiotics can help to reduce the deleterious effects of disease and antibiotics in critically ill patients: they can improve gut barrier function while reducing the load of pathogens in the gastro intestinal tract. This should reduce severe complications such as septicaemia, ventilator-associated pneumonia, and sepsis. As with all interventions there are risks involved, though these are limited when proper preparations and protocols are used.
This overview of the use of probiotics for critically ill patients does not claim to be complete. There are several reviews on the subject (1-6) published over the last few years and most of them in 2012 (1-3, 5).

BACKGROUND

Probiotics are defined by the United Nations Food and Agricultural Organization and the World Health Organization as ‘Live microorganisms which when administered in adequate amounts confer a health benefit on the host’. Prebiotics are primarily soluble food fibres that are ingested and which stimulate the growth of the lactobacilli and bifidobacteria that digest them in the colon. Synbiotics are combinations of selected microorganisms (probiotics) and prebiotic substances that promote the growth of the specific strains. In most studies discussed in this article single strain preparations or combination of strains have been used; there are, however, results presented in articles where synbiotic preparations have been used.
Microorganisms (bacteria and fungi) used for probiotic purposes must possess such qualities that they survive the passage through the gastrointestinal tract (GIT). They must resist the effects of gastric juice, pancreatic secretions and bile, surviving in to the small intestine and preferably as far as the colon. Besides being alive, bacteria which are to function as probiotics should be able to colonize and estab ...