Healthy Competition

From assisting digestion to supporting immunity, the bacteria inside our guts are critical to our health. In these diverse communities, pinpointing which specific bacteria are beneficial is difficult, but recent research on Salmonella enterica serovar Typhimurium, a strain of bacteria responsible for gastroenteritis, is providing new insights. Gut bacteria provide some protection from this form of Salmonella, so ingesting it only occasionally leads to disease. Yet, in mice, individuals lacking the bacterium Mucispirillum schaedleri in their intestines were more susceptible to infection, suggesting that Mucispirillum is especially important to their defences. In fact, when they co-exist in the gut, Mucispirillum (pictured, in green, with the gut lining in red) outcompetes Salmonella (in pink) to extract limited resources, such as nitrate, which Salmonella needs to synthesise major components of its weaponry. As we begin to understand microbial interactions in the gut, such competitive effects could suggest new ways of tackling pathogens.

Written by Emmanuelle Briolat

Emmanuelle Briolat

Writer

A researcher specialising in visual signals in Lepidoptera, camouflage and the effects of light pollution, Emmanuelle’s writing covers a range of topics, from biomedical research to children’s books about moth defences.

Website

• Image from B. Stecher, LMU Munich
• Max-von-Pettenkofer Institute, LMU Munich, Germany
• Image copyright held by the original authors
• Research published in Cell Host & Microbe, May 2019