'Good' gut bacterium outcompeting a 'bad' bacterial infection for nutrients protects the host
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
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