Bacteriophages are viruses that infect bacteria.  Phage is a Greek word meaning “to eat”.  Bacteriophages invade bacteria, replicate themselves and then destroy the host cell.  There are many types of viruses in the world.  Some infect only certain animals.  Some infect only humans.  But bacteriophages are by far and away the most numerous viruses.  They number 10 to the 31^st power on the planet and this number is greater than all of the other organisms on earth added together (including bacteria).  Despite being earths most populous organism science is just starting to understand their niche. 

In a previous newsletter we alluded to bacteriophages when discussing the immune mechanisms that bacteria have adapted to fight these viruses.  Now two new areas of research have looked at bacteriophages.  One has to do with gut bacteria, the phages they support, and cognitive health.  It seems that people whose gut microbiome supports the bacteriophages Caudovirales have better executive function and memory than people whose microbiome supports Microviridae.  When feces from humans with Caudovirales was transplanted into mice their performance on cognitive tests improved.  Examination of their brains revealed an up-regulation of the genes known to be associated with superior cognitive skills.  The potential application of this knowledge to humans with dementia is compelling.

The other area of research is harnessing bacteriophages to treat human bacterial infections.  The idea is to select phages whose prime host is the bacteria causing a certain illness.  Early efforts in this regard have been safe and effective.  If this continues to be the case, it may provide a safe answer to the rising problem of multidrug resistant infections.