Symbiotic gut bacteria reprogram our immune system
May 28, 2008
A team of scientists led by Sarkis K. Mazmanian, Assistant Professor of Biology, at California Institute of Technology have discovered that the bacterial flora of our gut can be actively stimulated to promote health.
The 100 trillion bacteria occupying the human gut have evolved alongside our digestive and immune system over millions of years. Intelligent bacteria have shaped their gut environment by positively interacting with the host immune system to promote health. Mazmanian reports the bacteria are actively modifying the gut through the mediation of molecules. The scientists have identified that a symbiotic gut bacterium Bacteroides fragilis, produces a sugar molecule called polysaccharide A or PSA with health boosting benefits.
In this case PSA induces immune-system cells called CD4+T cells to produce interleukin -10 (IL-10), a molecule shown to protect against inflammatory bowel disease.
The scientists predict that other types of symbiotic gut bacterium produce molecules with similar health benefits. This discovery radically changes our perception and relationship with our bacterial-ecosystem. It reveals that bacteria actually reprogram our own immune system to promote health.
As previously outlined in this blog and through my creative practice ‘The Race’ aims to create visions of a bacterial-centric society. As demonstrated by Mazmanian’s research, I feel we need to re-align our understanding or ourselves, our metagenomics and the complicated interactions we have with our human microbial ecosystem. To re-evaluate our behavior and lifestyles accordingly.
“Through societal measures we have changed our association with the microbial world in a very short time span. We don’t have the same contact with microbes as we have for millions of years–we just live too clean now,” Mazmanian says. So while it is useful to eliminate disease-causing organisms, “perhaps disease results from the absence of beneficial bacteria and their good effects,” he suggests. “This study is the first demonstration of that. What it hopefully will do is allow people to re-evaluate our opinions of bacteria. Not all are bad and some, maybe many, are beneficial.”