Ankylosing spondylitis (AS) is a chronic inflammatory disease which mainly involves the sacroiliac joints and spine [1]; it is considered to be most likely due to the interaction of genetic factors and environmental factors, such as microbial triggers. Its prevalence currently ranges from 0.10% to 1.60% in Europe and 0.29-1.98 in the Republic of Moldova (because of south region population – prevalence of Caucasians genes). The disease is often found among those 15 to 30 years of age and is characterized by inflammatory back pain particularly at the sacroiliac and spinal joints and by progressive ankylosis and disabilities [2,3]. AS is the primary form of seronegative spondyloarthropathies (SpAs) which include AS, psoriatic arthritis, reactive arthritis, and arthropathy of inflammatory bowel disease (IBD). The mechanisms leading to AS are unknown, although (HLA-B27) is known to be a major risk factor for AS, a genetic marker present in 90%–95% of AS patients. However, genetic predisposition fails to fully explain the cause of the disease, and this leads to a strong effort to identify additional predisposing factors, especially the patient’s microbiota.