They can cause diseases, but most of these microorganisms live in harmony with our body, and take care of essential functions for our survival. For the first time an international consortium of researchers, amongst whom VIB-VUB scientists, has mapped the different bacterial populations in the entire human body. This research leads to novel insights and is published in Nature.
Eco systems in balance
The VIB researchers Karoline Faust and Jeroen Raes (VUB) were mainly interested in unraveling the interactions between these species. Using computer models they constructed a network of positive and negative relationships between the bacteria in the different ‘eco systems’ of our body.
“Bacteria in these eco systems behave the same way as animals of human beings in populations” says Jeroen Raes, VIB group leader and professor bioinformatics and metagenomics at VUB. “They can collaborate in harmony to break down complex molecules, but sometimes it is wartime for certain nutrients. Thanks to this network we can now study the relationships between bacteria more in detail. We are mainly interested in how these ecosystems networks get disrupted in diseases and what we can do to repair them”.
Trillions of data processed
To define the normal human microbiome, 242 healthy volunteers (129 male, 113 female) were sampled, collecting tissues from 15 body sites in men and 18 body sites in women. Researchers collected up to three samples from each volunteer at sites such as the mouth, nose, skin, and lower intestine (stool).
The research showed that more than 10,000 microbial species occupy the human ecosystem. The human body contains trillions of microorganisms—outnumbering human cells by 10 to 1. They play a vital role in human health. The study also found that nearly everyone routinely carries pathogens, microorganisms known to cause illnesses. In healthy individuals, however, pathogens cause no disease. Researchers must now figure out why some pathogens turn deadly and under what conditions, likely revising current concepts of how microorganisms cause disease.