Triclosan may alter the composition of the intestinal microbiota and increase the susceptibility to experimental murine colitis

Abstract

Evidence suggests that alterations in the intestinal microbiota may play a role in the pathophysiology of inflammatory bowel disease. Triclosan, an antibacterial agent found in consumer products, is detectable in plasma and urine from sample human populations. The current study determined whether low doses of triclosan, mimicking environmental exposure, alter the intestinal microbiota and susceptibility to experimental colitis. Mice were given triclosan in the drinking water (10 μg/ml) for 6 days, followed by induction of colitis by 3.5% dextran sulfate sodium (DSS). Fecal bacteria were cultured for quantification of lactobacilli and coliforms. Fecal DNA was analyzed by PCR using bacterial genus‐specific 16S rRNA primers. Colitis was assessed by disease activity index (DAI) score, histological scoring, and western blot for cyclooxygenase‐2 (COX‐2). The day 4 DAI for the DSS + triclosan (DSS+T) group was higher than the DSS treated mice, but there was no difference at day 5 or 6. Triclosan did not alter induction of COX‐2 expression by DSS. Total fecal lactobacilli were greater in the control and triclosan versus DSS and DSS+T groups. Coliforms were increased by DSS and increased the most in DSS+T group. We conclude that low‐dose exposure to triclosan may increase susceptibility to DSS colitis may influence the composition of the intestinal microbiota. Supported by the MWSU College of Liberal Arts and Sciences.