The leaky Gut Syndrome-impairmo nt ot the gut wall funcfionality - is involved in marry inflamatory diseases, among them IBS.The aim of this work was to evaluate the effect of arabinogolactan (AG) and fructo-olligosaccharides (FOS) on gut wall modulation using a Simulator of the Human intestine Microbial Ecosystem (SHIME)-inoculated with faecal material from an IBS donor-coupled with co-cultures of enteracytes and macrophages (transwcll approach using Coco-2 and THP 1 cells).AG and FOS shwed a different fermentation piafile (more proximal for FOS and distol for AG) and both fibers exerted a potential pos. effect on gut barrier (increased TEER parameter) and inflammation (modulation of cytokines lL-8, IL-6, IL-1O and NF-kB) in their main area of fermentationAG could be an interesting nutritional supplement for the treatment at those conditions Characterized by inflammation and increased permeabiliry in the distal colon.