Ankylosing spondylitis (AS) and Crohn's disease (CD), especially when associated with spondylitis are interrelated conditions included within the categories of spondyloarthropathic disease entities. They share some common clinical, genetic, and microbiological findings. An extensive amount of studies which have been carried out by various independent groups throughout the world have shown that Klebsiella pneumoniae microorganisms could be suggested as the most likely etiopathogenetic triggers for AS and CD based on the molecular mimicry mechanism and the existence of the evidence for immunological, microbiological, and molecular link between Klebsiella and self antigens. It is proposed that the use of low starch diet in conjunction with the currently used treatment might help in the eradication of Klebsiella microbes from the bowel and could result in the stoppage and alleviation of the disease process in patients with AS and/or CD.