Small secreted proteins called microcins can limit the growth of harmful gut-dwelling bacteria, such as pathogenic Escherichia coli and Salmonella enterica, during intestinal inflammation, reveals a study in mice published in Nature. If these findings can be translated to the clinic, the antibiotic activity of these molecules could prove useful in the treatment of inflammatory bowel disease.
The healthy gut is home to various different bacteria, but when it becomes inflamed, the balance of bacteria changes and disease-causing bacteria can gain the upper hand. However, the mechanisms through which microbes compete for a niche in the gut remain poorly understood.
Manuela Raffatellu and colleagues show how the expression of small proteins called microcins enables a probiotic strain of E. coli to limit the expansion of other pathogenic bacteria during intestinal inflammation in mice. The probiotic bacterium uses microcins to compete with related bacterial species, colonize the inflamed gut and then displace the disease-causing bacterium from its niche. This is the first time that microcins have been shown to mediate inter- and intra-species competition among the Enterobacteriaceae in the inflamed gut. The narrow spectrum of microcins allows for precision interventions that target pathogens without disturbing the gut microbiota, which makes them attractive for therapeutic development.
Article: