Researchers at the European Molecular Biology Laboratory Bioinformatics Institute (EMBL-EBI) and the Wellcome Sanger Institute have identified 2,000 new species of bacteria living in the human gut, which as of now have not been cultured in a lab.
It can be difficult to identify all bacteria species that occupy the gut microbiome because of low abundance or an inability to survive outside the gut, therefore a range of computational techniques were employed to analyse samples from individuals all over the world.
“Computational methods allow us to understand bacteria that we cannot yet culture in the lab. Using metagenomics to reconstruct bacterial genomes is a bit like reconstructing hundreds of puzzles after mixing all the pieces together, without knowing what the final image is meant to look like, and after completely removing a few pieces from the mix just to make it that bit harder,” says Rob Finn, Group Leader at EMBL-EBI. “Researchers are now at a stage where they can use a range of computational tools to complement and sometimes guide lab work, in order to uncover new insights into the human gut.”
Explaining further, Alexandre Almeida, Postdoctoral Fellow at EMBL-EBI and the Wellcome Sanger Institute, says “computational methods allow us to get an idea of the many bacterial species that live in the human gut, how they evolved and what kind of roles they may play within their microbial community.”
The research also highlighted how the composition of gut bacteria is different in individuals from different locations around the world.
“We are seeing a lot of the same bacterial species crop up in the data from European and North American populations,” explains Finn. “However, the few South American and African datasets we had access to for this study revealed significant diversity not present in the former populations. This suggests that collecting data from underrepresented populations is essential if we want to achieve a truly comprehensive picture of the composition of the human gut.”
Differences in gut bacteria makeup have previously been linked to differences in diet, which could explain why the bacterial makeup of people from North America and Europe is different from people from Africa and South America.