The modern view of probiotic therapy derives from the concept of a well functioning gut barrier and a normal balanced microbiota. The scientific conception of these host defences has changed; the gut barrier was seen primarily as a physical blockade to foreign antigen entry until its active role in shaping the immune response to luminal antigens was deciphered. Concomitantly, recent experimental and clinical studies demonstrate a dependency on healthy host-microbe interaction to cope with antigen challenges, and consequently attribute the gut microbiota an active role in barrier function.^1–3

The most fully documented probiotic intervention is the treatment of acute infectious diarrhoea. Well controlled clinical studies have shown that probiotics such as Lactobacillus rhamnosus GG, L reuteri, L casei Shirota, and Bifidobacterium lactis Bb12 can shorten the duration of acute rotavirus diarrhoea.^4,5 Numerous publications on different populations have since substantiated the success of specific probiotic strains in the adjunct management of viral …