<p>The oral microbiome, which is known as the diverse and abundant microbial community within the human oral cavity, is an integral part of the human body. The investigation of its composition and functions in both wellness and illness has received notable attention from researchers in recent times. The presence of oral bacteria directly impacts the disease condition of dental caries and periodontal diseases. The oral microbiota interacts dynamically with the host to influence immune regulation and metabolic processes. Advances in sequencing technologies, including whole-metagenome shotgun sequencing, the examination of 16S ribosomal RNA, and meta-transcriptomes, we now possess the capability to comprehensively explore the diversity and functionalities of oral microorganisms, encompassing those that are not amenable to cultivation. As research advances, there is a growing body of evidence suggesting the notable contribution of the oral microbiome to various health conditions, extending beyond ailments solely associated with the oral cavity. This review advances current understanding by presenting a systemic, integrative perspective on the oral microbiome’s role in chronic diseases, offering novel hypotheses and therapeutic directions beyond those explored in prior literature.</p> Graphical abstract <p>Oral microbiota and various diseases</p> <p></p>