Adhesion of inactivated probiotic strains to intestinal mucus

It has been suggested that probiotics should be viable in order to elicit b eneficial health effects. Inactivation of probiotics has been suggested to interfere with the binding to the mucosa and thereby with the immune modula ting activity of probiotics. The effect of different inactivation methods o n the mucus adhesion of nine probiotic strains was studied. Inactivation by heat or gamma-irradiation generally decreased the adhesive abilities. Howe ver, heat treatment increased the adhesion of Propionibacterium freudenreic hii and gamma-irradiation enhanced the adhesion of Lactobacillus casei Shir ota. Inactivation by u.v. was not observed to modulate the adhesion of the tested strains and it was concluded to be the most appropriate method for s tudying non-viable probiotics and preparing control products.