We all carry around a massive community of microbes in our gastrointestinal tracts, which help us digest food and absorb nutrients. Called the gut microbiome, those microbes can have a powerful effect on human health (as explained in the video). Scientists naturally want to know more about all of the different species of microorganisms in that microbiome. Characterizing them will allow us to find the ones that contribute to disease or others that have therapeutic potential, for example. But to do so, researchers need a reference point.
Now scientists from the Wellcome Sanger Institute, Hudson Institute of Medical Research, and the European Bioinformatics Institute at EMBL have described 100 new bacterial species that live in the human gut. Their work, which has been reported in Nature Biotechnology, will help researchers quickly identify the microbes that are in any sample they might be analyzing. They can then make connections between various health conditions and specific gut bacteria.
"For researchers trying to find out which species of bacteria are present in a person's microbiome, the database of reference genomes from pure isolates of gut bacteria is crucial. Then if they want to test a hypothesis, for example, that a particular species is enriched in a certain disease, they can get the isolate itself from the collection and physically test in the laboratory if this species seems to be important,” explained study author Dr. Rob Finn of EMBL's European Bioinformatics Institute.
Gut microbes are adapted to live in a special environment, making them very difficult to grow in the laboratory. While we know that many of these microbes have an influential role in disorders like obesity, irritable bowel syndrome and allergies, we don’t know much about them.
In this work, the researchers were able to successfully grow 737 individual strains of bacteria and sequence their genomes. Of those, 173 had never been sequenced, and of that group, 105 had never been isolated. They were able to do so after collecting fecal samples from only 20 donors.
"This study has led to the creation of the largest and most comprehensive public database of human health-associated intestinal bacteria. The gut microbiome plays a major [role] in health and disease. This important resource will fundamentally change the way researchers study the microbiome,” said the first author of the report Dr. Samuel Forster of the Wellcome Sanger Institute and Hudson Institute of Medical Research.
Most human fecal samples contain a huge mixture of microbial species, and they can be challenging to analyze without reference genomes that can identify the microbes. This work will change that.
"This culture collection of individual bacteria will be a game-changer for basic and translational microbiome research. By culturing the unculturable, we have created a resource that will make microbiome analysis faster, cheaper and more accurate and will allow further study of their biology and functions. Ultimately, this will lead us towards developing new diagnostics and treatments for diseases such as gastrointestinal disorders, infections, and immune conditions,” said the senior author of the report Dr. Trevor Lawley of the Wellcome Sanger Institute.
In the video above, Lawley explains why some bacteria is good for us.