Most of us know about the so-called ‘, or methcillin-resistant Staphylococcus aureus, and the health problems it causes. Our history of overusing antibiotic drugs has resulted in strains of bacteria that have adapted defenses against those same , leaving us in quite a quandary.

There have also been concerns that may contribute to antibiotic resistance. The conventional line of thinking has been that, like antibiotic drugs, soap kill off most bacteria, leaving only a few resistant strains behind, which then multiply and spread. However, a new study has shown something completely unexpected: Some antibacterial soaps may actually promote bacterial colonization.

Triclosan is a common ingredient in antibacterial soap, and is the main one responsible for killing bacteria. It’s so common, in fact, that it has begun showing up in the human body and human secretions. In a study published yesterday, researchers found that triclosan is present in the nasal secretions of healthy adults, but that, against expectations, the presence of triclosan in the nasal passages is associated with an increased incidence of Staph aureus colonization, not a decreased incidence.

One might reasonably expect that presence of triclosan in the nasal secretions might help keep out bacteria through antibacterial action, but such is not the case. Instead, the triclosan was present only at nonlethal levels, which, rather than killing the bacteria, simply stressed them and caused them to react. What was their reaction, you ask? Their reaction was to attempt to adhere to local proteins within the nasal passages, forming what bacteriologists call a “biofilm.” When bacteria form a biofilm, they’re hunkering down for good. The findings of the study show that rather than keeping us squeaky clean, antibacterial soaps actually encourage bacteria to take up residence on our bodies.

It’s an old adage that cleanliness is next to godliness. While I won’t argue with that, antibacterial cleanliness may be a lot closer to unwanted Staph aureus than any deities. When washing, it’s the mechanical action of scrubbing and a mild detergent effect that we need most, not “bacteria fighting power.” So go for natural soaps, or at least conventional soaps without added antibacterial agents.