Residues of the antimicrobial agent triclosan can paradoxically boost bacterial growth in our bodies, by giving microbes a comfortable biofilm in which to rest. Christopher Intagliata reports
The antimicrobial triclosan is a common ingredient in hand soap. But it's also found in shampoos, deodorants, toothpaste, even lip gloss. So it's not too surprising that triclosan also shows up in blood, urine, breast milk and mucus. But here's the weird thing—those triclosan residues may actually boost bacterial growth in our bodies. So says a study in the journal mBio. [Adnan K. Syed et al, Triclosan Promotes Staphylococcus aureus Nasal Colonization]
Researchers swabbed inside the noses of 90 adults. 37 of the 90 tested positive for triclosan—and those who did were twice as likely to have the bug Staphylococcus aureus living in their noses. Rats, too, were more susceptible to staph if fed triclosan.
Seems counterintuitive, but when bacteria are exposed to sublethal levels of antibiotics, they get stressed, and “they attach to surfaces and hunker down, in things we call biofilms." That's study author Blaise Boles, of the University of Michigan.
For the rest of the story: http://www.scientificamerican.com/podcast/episode/triclosan-biofilm-staph/