Researchers have shown the extent to which microbial communities are linked to each other across the body, and how these networks are associated with susceptibility to respiratory infections in babies.
In a presentation at the European Respiratory Society International Congress today (Tuesday) [1], Dr Melanie Clerc, a post-doctoral researcher at the Centre for Inflammation Research, University of Edinburgh (UK), said that infants whose microbial communities (known as microbiota) were organised into networks of large, well-connected clusters had fewer respiratory infections than those with more fragmented networks.
She said: “We know already that bacteria in the gut and respiratory tract are independently associated with susceptibility to and severity of respiratory infections. Up until now, however, researchers have mostly focused on the links between a particular disease and either the bacteria in the gut or the local bacterial community at the site of disease, like the lungs. We believe we are the first group to show the extent to which microbial communities are linked across different sites in the body, and that having a well-structured, stable microbial network from an early age can be linked to improved respiratory health over the first year of life.”
The researchers, led by Professor Debby Bogaert, collected samples one week after birth and then at two, four and six months from the nose, mouth and gut of 120 healthy babies who were enrolled in the large prospective Microbiome Utrecht Infant Study in The Netherlands. The researchers also gathered information on lifestyles and environmental factors affecting the babies, and how many respiratory infections they developed in the first year of life.
Dr Clerc said: “We analysed the bacteria present in the nose, mouth and gut at multiple timepoints and used a mathematical algorithm to create networks that describe how all of those microbes are linked at each timepoint and over time.”
The researchers found that one week after birth the microbial networks were already well-defined in babies who went on to experience 0-2 infections in the first year of life. These networks were composed of four large clusters of bacteria: three clusters were specific to either the nose, the mouth or the gut, and a fourth cluster of bacteria, composed of species of mixed origin, linked the other three groups. The size, composition and connectivity of these clusters remained stable during the year.
“However, the networks from children who developed more respiratory tract infections showed small, less-well connected clusters from early on in life, and they tended to change more over time, even before infections occurred,” said Dr Clerc.
“Our findings may lead to new insights into ways of using these cross-site microbial connections to prevent respiratory infections in childhood and to understand how susceptibility to disease is linked to the way these microbial communities mature. Further, interventions immediately before or after birth, such as caesarean section or antibiotic treatment, migh