Bovine Meat and Milk Factors

Bovine Meat and Milk Factors (BMMFs) are circular, single-stranded DNA molecules (cssDNAs) originally found in beef and cow's milk which have been linked to the development of cancer—particularly colorectal and breast cancer.^[1] They are formerly known as Slow Progressive Hidden INfections of variable X (SPHINX). Similar molecules have since been found in a much wider range of food.^[2]

BMMF/SPHINX sequences are able to copy themselves in animal cells. They encode functional proteins that are expressed in some animal cells. Every BMMF/SPHINX contains at least a "Rep" open reading frame, which encodes a replication endonuclease that, in HEK 239TT cells, acts to replicate and retain the cssDNA.^[3]

BMMF/SPHINX sequences are divided into four clades. Clades 1, 2, and 3 share sequence similarity with the plasmids of Acinetobacter baumannii. (A. baumanii regularly produces outer membrane vesicles containing these plamids, and animal cells are known to take up these vesicles.) Clade 4 shares sequence similarity with Gemycircularvirus.^[3]

Health research

The potential connection between BMMFs and cancer has been made based on assessments of epidemiological data^[4][5][6] and the investigation of antibodies in human serum.^[7][8] Research has also suggested a potential link between BMMFs and neurodegenerative diseases such as multiple sclerosis.^[7]

At the end of 2017, evidence was presented that BMMFs in human cells show long-term survival, through the identification of BMMFs' RNA and protein products.^[7][9] In February 2019, evidence was presented of a previously unknown infectious agent in the blood serum and milk of Eurasian cattle that could indirectly trigger the development of colorectal cancer.^[5]