FIGURE 1.

The overlapping factors that influence IBD, IBS and the microbiome. Schematic representation of the factors that contribute to IBD and IBS. Dashed lines represent pathways requiring further evidence. Barrier function and permeability may be the key to pathogenesis in both disorders and be the critical factor in mucosal interaction with the microbiota. Most relationships with the microbiota will be bidirectional, increasing the complexity of understanding its effects. IBD, inflammatory bowel disease; IBS, irritable bowel syndrome.