Pesticides May Wreak Havoc on the Gut Microbiome

Eight years ago, Bhanudas More went for a routine blood test. More, a farmworker in this small village in Maharashtra state, was lean, worked long hours in the fields, and seemed healthy, so the result startled him. He was diagnosed with type 2 diabetes, a disease commonly associated with sedentary life in the city.

Medication did little to bring his condition under control. He also began to experience persistent bloating and stomach discomfort. “I was taking the medicines, but I still didn’t feel normal,” says More, who is now 56. “Some days, it was hard to get through the work.”

The source of his problems remains mysterious, but doctors uncovered a clue when they asked about his working conditions. In the sugarcane and grape fields where he labors, More is routinely exposed to a mix of crop pesticides. A rapidly growing body of research suggests those chemicals may disrupt the gut microbiome, the ecosystem of trillions of bacteria, fungi, and viruses that help digest food, produce essential nutrients, train the immune system, and send chemical signals that influence metabolism and even brain function. Such disruptions could lead to a host of medical problems, researchers say, among them the global rise of type 2 diabetes in nonobese people.