Antibacterial Soap May Disrupt Intestinal Microbiota in Fetuses

A new study reveals that using nonprescription soaps containing the antimicrobial triclocarban (TCC) during pregnancy and breast-feeding may alter the composition of intestinal bacteria in offspring.

Researchers at the University of Tennessee (Knoxville, USA) conducted a study that involved feeding female rats chow supplemented with TCC throughout pregnancy, and during a 16-day nursing period after the rat pups were born. They collected fecal samples from the maternal rats during pregnancy and nursing, and also collected the contents of the cecum—an area connecting the small and large intestines—from the nursing pups to test the gut microbiota.

The researchers then performed DNA sequencing of the collected samples, and compared them with gut microbiota analysis of rats and their pups that were not exposed to TCC. The results showed that TCC led to a reduced average number of the microbial taxa present among mother rats and their pups; in addition, by postnatal day 16, the nursing pups exposed to TCC had a significantly different composition of gut microbiota from that of unexposed pups. The study was presented at the Endocrine Society's 98th annual meeting, held during April 2016 in Boston (MA, USA).

“Many antibacterial personal care products are commonly used during pregnancy and by nursing women to protect against infectious disease,” said lead author graduate student Rebekah Kennedy, MSc. “The ability of TCC antimicrobial exposure to change the composition of the microbial community warrants future investigation to determine the health outcomes … during sensitive windows of prenatal development and early life.”

Over 2,200 anti-bacterial hand soaps and body washes are currently available for consumers in the United States, but there is no scientific evidence showing these products are any more effective at preventing illness than washing hands with plain soap and water. In fact, some data suggest that long-term exposure to certain active ingredients used in anti-bacterial products, such as triclosan and TCC, could pose health risks such as bacterial resistance or interference with hormones such as estrogen, testosterone, and thyroid hormones.

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