It needs to be further investigated if underlying systemic conditions can modify the serum antibody responses to Rosavin periodontal pathogens, as well as their relationship is to periodontal inflammation. To date, the relationship between oral microbiota, gingival inflammation and systemic antibody response in presence of PCOS has not been investigated. The hypothesis of this study is that salivary levels of putative periodontal pathogens, as well as the serum antibody levels to them are elevated in patients with PCOS, particularly in the presence of gingival inflammation. The incidence and Palmatine clinical presentation of plaque-induced gingivitis are affected by increased sex steroid hormone levels. Puberty has a transient effect on the inflammatory status of the gingiva, but the severity or the time of onset of gingival inflammation varies in different studies. Severity of gingivitis during the pregnancy can be increased independently from dental plaque accumulation. A quantitative shift in the subgingival levels of Gram-negative anaerobic microorganisms occurs during the second trimester of pregnancy. The likely explanation is that the local accumulation of active progesterone and oestrogen may provide the essential nutrients that selectively enhance their growth. Androgen production is a major trait of PCOS and essential for follicle development. Although the overproduction of luteinizing hormone is evident, the absence of the peak level of the hormone results in higher levels of progesterone and estrogen production. Such hormonal changes in PCOS are likely to influence the salivary levels of putative periodontal pathogens, or their systemic antibody responses, particularly when associated with gingival inflammation. To our knowledge, this is the first study to investigate the association between PCOS and oral microbiota in saliva and their serum antibody responses, in regards to gingival inflammation. The findings demonstrated that the levels of most of the studied putative periodontal pathogens, except A. actinomycetemcomitans and T. denticola, were elevated in women with PCOS and gingivitis compared to the matched periodontally healthy controls.