Antimicrobial toxin passed on to pups by lactating mothers promotes liver damage

In mouse studies,  lactating mothers expose their feeding pups to triclosan, an antimicrobial commonly used in consumer products, resulting in early signs of liver damage that can eventually lead to more serious impairment and illness, such as nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH).

The findings published in the journal Nature Communications.

NAFLD is the most common chronic liver condition in the United States, affecting an estimated 100 million adults. It occurs when fat accumulates in liver cells due to causes other than excessive alcohol use, impairing organ function. The precise cause is not known, but diet and genetics play substantial roles. Up to 50 percent of obese people are believed to have NAFLD.

Approximately 20 percent of persons with NAFLD transition to NASH, a more advanced form of the disease characterized by increasingly severe inflammation and organ damage that may result in scarring of the liver, cirrhosis and cancer.

The prevalence of NAFLD in children is rising, along with obesity rates in the young. It is estimated that 9.6 percent of children ages 2 to 19 years have NAFLD. A recent study by scientists found that pediatric NAFLD increases the risk of developing type 2 diabetes later in life.

Triclosan is an ingredient added to diverse consumer products to reduce or prevent microbial contamination, including soaps, toothpaste, cosmetics, clothing, furniture, kitchenware, pesticides and toys.

“Triclosan is a broad-spectrum antimicrobial agent that is used in many personal care products, and impregnated in numerous different materials, ranging from clothing to food packaging. It has been linked to multiple adverse health effects,” said the study’s corresponding author.

In 2016, fueled by rising evidence and public health concerns, the U.S. Food and Drug Administration banned the use of triclosan in some products and required premarket approval for others. It remains an ingredient in many products.

Two years ago, the authors published evidence that triclosan exposure worsened fatty liver disease in mice fed a high-fat diet. The latest research builds upon how that happens, showing that triclosan is passed from nursing mothers to pups, who develop early signs of fatty liver pathogenesis and perhaps a greater likelihood of fatty liver disease later in life.

The researchers exposed pregnant females to triclosan in their diet and found that it was efficiently transferred by lactation to newborn mice, causing significant fatty liver during the suckling period, and resulting in hepatosteatosis, triglyceride accumulation, endoplasmic reticulum stress, signs of inflammation and liver fibrosis. Two key metabolic regulators responsible for triclosan-induced fatty liver disease were identified.

“Early exposure to triclosan appears to trigger pathologies that resemble NAFLD and NASH: toxicant associated fatty liver disease and toxicant associated fatty liver disease, which may predispose development of pediatric NAFLD and NASH,” said the author. “Recent increases in pediatric NAFLD could be a consequence of mother-to-child transmission of environmental toxicants like triclosan.”