Should probiotics be tested on ex vivo organ culture models?

The use of probiotic strains as nutritional supplements has been gaining ground in the last decade. As the mechanisms with which they modulate innate and adaptive immunity start to unravel, probiotics have repeatedly been suggested as potential treatment for a wide variety of diseases, including inflammatory bowel disease (IBD). However, even though the benefits of probiotic treatment for conditions like atopic dermatitis are well established, very limited clinical benefit has been obtained on IBD treatment. This could be due to the lack of suitable models on which to obtain valid pre-clinical data to select the most appropriate strain for a given condition. We recently described a newly developed model for the culture and apical stimulation of whole human intestinal mucosal explants. We showed that the tissue was only viable if incubated in an O(2) chamber, but it was possible to stimulate the tissue with bacteria in a conventional incubator. We used the new set-up to test three different Lactobacilli strains, none of which appeared to be benign on inflamed IBD mucosa.