Abstract
Probiotics have received increased attention in recent years. There are a large number of papers evaluating their effect in various diseases, but only relatively few studies are of a really high quality.
Probiotics act by several mechanisms, such as intestinal pH reduction, decreased colonization by pathogenic microorganisms, and modulation of immune response. A positive effect of one probiotic in a certain situation may not necessarily be apparent with the use of another probiotic.
Probiotics have been clearly shown to be effective in treating gastrointestinal diseases, such as acute viral gastroenteritis, antibiotic-associated diarrhoea, travellers diarrhoea, and pouchitis. Studies have also demonstrated their efficacy in maintaining remission in the treatment of idiopathic proctocolitis and irritable bowel syndrome.
Study findings imply that administration of probiotics significantly reduces the risk of severe necrotizing enterocolitis and, thus, that of mortality in premature infants. Enrichment of infant milk formulas with probiotics is safe, but data on their long-term positive effect on the health of children are still lacking.
There are certain data indicating that enrichment of infant milk formulas with probiotics results in lower morbidity rates and a lower incidence of atopic disease in otherwise healthy infants. However, their long-term positive effect on the developing immune system is yet to be proved.
The importance of probiotics in the primary prevention of allergies has been evaluated, with some studies having shown a positive effect of probiotics on early manifestation of atopic eczema; however, other similar studies have shown no effect. The study of therapeutic use of probiotics requires randomized, double-blind, placebo-controlled studies, which is the only way to adequately assess the efficacy and safety of individual probiotics.