Current Research on Small Circular Molecules: A Comprehensive Overview on SPHINX/BMMF

Several years of research into the small circular DNA molecules called SPHINX and BMMF (SPHINX/BMMF) have provided information on several areas of research, medicine, microbiology and nutritional science. But there are still open questions that have not yet been addressed. Due to the unclear classification, evolution and sources of SPHINX/BMMF, a risk assessment is currently not possible. However, risk assessment is necessary as SPHINX/BMMF are suspected to be involved in the development of cancer and neurodegenerative diseases. In order to obtain an overview of the current state of research and to identify research gaps, a review of all the publications on this topic to date was carried out. The focus was primarily on the SPHINX/BMMF group 1 and 2 members, which is the topic of most of the research. It was discovered that the SPHINX/BMMF molecules could be integral components of mammalian cells, and are also inherited. However, their involvement in neurodegenerative and carcinogenic diseases is still unclear. Furthermore, they are probably ubiquitous in food and they resemble bacterial plasmids in parts of their DNA and protein (Rep) sequence. In addition, a connection with bacterial viruses is also suspected. Ultimately, it is still unclear whether SPHINX/BMMF have an infectious capacity and what their host or target is.