Gut bacteria populations can transmit between humans, study finds

A study published in the journal Nature, coordinated by the University of Vienna, suggests that certain populations of gut bacteria can pass from one person to another and establish themselves in a new host if conditions are suitable.

Researchers utilized a genetic analysis method known as ‘reverse ecology’ to examine thousands of gut bacteria and genetic data from individuals across multiple countries. The study found that instead of being uniform, a single species can contain distinct bacterial populations that occupy different niches. Some highly competitive bacterial populations appear to have spread rapidly across different continents within just a few decades, a pattern previously observed primarily in pathogens.

However, the research clarifies that this does not mean the entire microbiome is contagious like a respiratory infection, nor does it mean a person automatically transmits their whole microbiome to another. The successful establishment of these bacteria depends on the host's intestinal environment, including diet, medication, and lifestyle.