Like the Ayurvedic notion of ama, or the modern view of leaky gut syndrome, there is a conceptualization that undigested food or other imbalances in the digestive tract can lead to a cascade that ultimately results in autoimmune responses.
If the intestinal wall is compromised then things that shouldn’t be getting through start to get through. The immune system has to respond to this but the response is not always to the benefit of the host.
We have begun to understand aspects of this whole process, like the inflammation of the digestive tract, perforations in the mucosal lining, and the production of antigens.
A new study has, and of course more research is needed, pointed to a new mechanism to be aware of: biofilms produced by bacteria may be one of the factors bringing about autoimmune responses.
Wikipedia provides us with a concise definition of biofilms:
A biofilm is any group of microorganisms in which cells stick to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS). Biofilm extracellular polymeric substance, which is also referred to as slime (although not everything described as slime is a biofilm), is a polymeric conglomeration generally composed of extracellular DNA, proteins, and polysaccharides. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single-cells that may float or swim in a liquid medium.
Proinflammatory cytokines were noted in significant quantity in response to these biofilms. A biofilm has different qualities than its constituent bacterium in isolation. While infections of bacteria can be problematic and lead to these biofilms so can healthy bacteria too if there is a leaky gut present. This is all working towards understanding how the presence of bacteria in our body interacts with the immune which is clearly a fruitful direction of inquiry.
See the study for more information: Amyloid-DNA Composites of Bacterial Biofilms Stimulate Autoimmunity
We have a forum thread about leaky gut syndrome.