Faecalibacterium prausnitzii is very special. It is a gut barrier and immune system warrior and known as a keystone ‘Peacekeeper‘ (Nature 2015, fantastic photos).You can see above it is a red-orange and found in robustly in concentration of hundreds in 94% of tested healthy subjects. In clinical trials, it is low where diseases are present and high in disease-free people. It is a harbinger for bad health if it and several other ‘ancestral core’ species are depleted. (source)
In the mid-2000s Harry Sokol, a gastroenterologist at Saint Antoine Hospital in Paris, was surprised by what he found when he ran some laboratory tests on tissue samples from his patients with Crohn’s disease, a chronic inflammatory disorder of the gut. The exact cause of inflammatory bowel disease remains a mystery. Some have argued that it results from a hidden infection; others suspect a proliferation of certain bacteria among the trillions of microbes that inhabit the human gut. But when Sokol did a comparative DNA analysis of diseased sections of intestine surgically removed from the patients, he observed a relative depletion of just one common bacterium, Faecalibacterium prausnitzii. Rather than “bad” microbes prompting disease, he wondered, could a single “good” microbe prevent disease?
Sokol transferred the bacterium to mice and found it protected them against experimentally induced intestinal inflammation. And when he subsequently mixed F. prausnitzii with human immune cells in a test tube, he noted a strong anti-inflammatory response. Sokol seemed to have identified a powerfully anti-inflammatory member of the human microbiota.
• In a healthy gut, represents more than 5% of the total bacterial population and is comprised of only one species • Abundance associated with higher bacterial gene richness in the gut • Controls inflammation through inflammatory-cytokine inhibition; lower counts reported in IBD: Crohn’s disease and ulcerative colitis (UC), although increases have been noted • Appears to protect against glucose intolerance and type 2 diabetes; possibly due to anti-inflammatory effects and/or positive effects on insulin resistance status (source)