Microbial communities are like a noisy orchestra: thousands of instruments, and it's hard to tell who's playing the lead. In the gut, ocean, or soil, millions of bacterial species live, and scientists need to figure out which ones truly matter for human health or soil fertility.
The new approach works like smart laundry sorting. Instead of folding each item individually, the algorithm finds similar groups on its own — say, all socks or all T-shirts. Here, instead of clothes, we have microbes; instead of color and size, we have their genes and functions. The neural-network-based algorithm groups microbes by what they do: who breaks down nutrients, who produces vitamins, who protects against harmful bacteria.
In soil, the algorithm singled out just two groups from 4400 bacterial species that fed into a mathematical model of nitrogen cycling. It turned out these groups respond differently to environmental changes — for example, to fertilizer application. This allows predicting how soil will react to human intervention.
This approach not only explains how microbial communities are organized but also helps uncover the molecular mechanisms of health and disease. Instead of studying thousands of species individually, scientists can focus on key groups and their interactions.
A single gram of soil can harbor more bacteria than there are people on Earth — up to 10 billion.
In Adrian Tchaikovsky's novel Children of Time, spiders build a civilization by managing microbial communities for water purification and food production — an idea that echoes the search for key microbial groups to manage ecosystems.