Why bacterial extracts can’t help your DNA

Life depends on the separation (and selective transport) between compartments. You destroy cell membranes and you destroy life.

I find it appalling how the media (aided by doctors who seem to have forgotten all the biology they ever learned!) provide free advertising to products that promise to reverse UV damage using ingredients that can’t possibly fix UV damage to human skin. The products contain a bacterial extract that would contain an enzyme capable of fixing DNA damage in bacteria. Bacterial DNA is very different from human DNA and so are the enzymes capable of repairing them.

There is no question that the DNA repairing enzymes of Micrococcus help this bacterium recover from UV damage to its DNA. The question to answer is “are you a bacterium”? If the answer is “no”, then don’t buy the products, and don’t believe the marketing that goes with it.

Life depends on permeability properties and separation between compartments. For a molecule to enter the nuclear membrane though its pores, it needs to have the right sequence that will be recognized by the nuclear membrane. So it is fortunate that the DNA fixing enzymes supposedly present in this bacterial extract will NOT enter your cells (and certainly not your cells’ nuclei), otherwise you may risk a bad allergy that may turn into your body attacking your own DNA repair enzymes.

I will not repeat here the misinformation concerning these products, as misinformation has a way to reach people in a way that real science doesn’t (misinformation is a lot more exciting!) but avoid anything that contains “Micrococcus lysate”.

You have your enzymes that repair DNA, and they are very good at it. Conversely, you cannot use foreign enzymes to enter the cells of your body and then the nuclear envelope and fix YOUR DNA. This does not happen thanks to a very effective immune system that is there to protect us from foreign microbes.

Worth noting: genetic engineering to cure serious illness relies on changing the patient’s DNA. You may be aware of how much effort this requires and how slow progress is. This is because you can’t interfere with DNA in a direct way unless you have very sophisticated molecular tools like CRISPR.

I love science fiction, but in literature, like Ray Bradbury. Not in advertising.