Scientific article, linking between health and gut microbiota diversity
Numerous experimental articles report that a higher diversity of the gut microbiota is correlated to an improved health status. However, to date there is no mechanistic motivation for this yet. The gut microbiota can be envisioned as a large network of “nodes” (the microorganisms) and “edges” (the signalling between the microorganisms). Recently, an article was published that modelled the microbiota as such a network in order to search for a mechanistic rationale why diversity is linked to health. Microbial guilds were used as first model systems. Guilds are small networks of microorganisms that interact with each other or share a metabolic process. Typically, a guild starts of by production of some metabolite by species 1, which is again being processed by species 2, producing a metabolite for species 3, and so on, until the final “end-product” is being produced. It has been recently suggested that the human gut microbiota indeed consists of microbial guilds. As these guilds already start from systems comprising of only two different species, they provide an interesting link between understanding at single cell level to understanding of large scale networks like the human gut microbiota (consisting of roughly 1013 microorganisms, closely equivalent to the number of human cells). In the article, all possible signalling configurations for different microbial guilds (n, ranging from 2 up to 7 species) were calculated, together with their associated signalling paths going from the “start “node (species 1) to the final “target” node (species n). The results indicated that higher diversity leads to a more “relaxed state” of the microorganisms: relatively less interaction is needed to still maintain the highest signalling strength. As such, higher diversity leads to a more efficient system. Also redundancy in the system could be observed, when introducing more species into the guild.
The full, open-access, article can be found here