Agriculture has a math problem. To feed an extra two billion people by 2050—the equivalent of six more United States—the world will need to increase crop production by 70% to 100%. But yield gains have slowed to just 1% a year, and the technology farmers rely on for those meager gains, such as pesticides, cause problems of their own.

The plant microbiome evolved with the plant over millions of years until modern technology systematically decimated them.

A Cambridge-based startup called Indigo, which announced a $56-million funding round today, thinks the solution may lie in probiotics for plants. By dosing seeds in healthy microbes, farmers can grow as much as 10% more food, and as the technology develops, yields may increase even more.

The startup was inspired by research on the human microbiome—the trillions of microbes that live on and around us, affecting everything from our mood to how likely we are to get cancer. Plants, it turns out, have a microbiome of their own, and just as antibiotics wreak havoc on the human microbiome, pesticides and other chemicals have affected the health of crops.

“The plant microbiome, the natural community of microbes that live inside of the plant, evolved with the plant over millions of years until modern technology has sort of systematically but unconditionally decimated them,” says CEO David Perry. “Those inventions were tremendous breakthroughs and allowed us to feed hundreds of millions of people, but they also had unintended negative consequences.”

The researchers at Indigo have spent the last two years sequencing 40,000 microbes—the largest body of data that exists on the microbial makeup of plants—and figuring out how to bring those beneficial microbes back to farms.

“What we do in concept is really simple: We go and try to identify what those lost beneficial microbes are, and we add them back in the form of a seed coating,” Perry says. “So it gets coated on the seed before it goes in the ground, and the result is a healthier plant.”

Microbes can help plants grow with less water, in hotter weather, and in saltier soil—the types of stress that are becoming more common as the climate changes.