The New England Journal of Medicine recently published research regarding triclosan and its effect on bacteria.
Triclosan is a poly-chlorinated aromatic compound that targets fatty acid synthesis. It is found in household items such as some toothpastes, deodorants, and shaving creams. It is added to these products because of its antimicrobial properties. Measurable levels of triclosan can be found in the urine of 10% of Americans.
Unfortunately, chronic low-level exposure to triclosan can lead to bacteria becoming resistant to medicinal antibiotics. Two examples are multi drug resistant E. coli (a common cause of urinary infections) and multi drug resistant Staph (MRSA).
The FDA has banned the use of triclosan in soaps for this reason. But unfortunately, this prohibition does not include other commonly used products.
Other than promoting antibiotic resistant bacteria, there is also an impact of triclosan on the normal human flora (the microbiome). The long-term health consequences of changes in microbiome have yet to be studied.