Diet, Your Brain and Autoimmunity

By now, we all know that chronic and/or neurodegenerative diseases like MS, Alzheimer’s, Parkinson’s, ALS, autism are all inflammatory and probably all derive from alterations to the gut biome.  I’ve written about all of them many times now (some links provided in the previous sentence), as I follow this research.  I read an interesting article yesterday that is absolutely worth sharing, as it has a fascinating premise.[i]

Remember that, in theory, the inflammatory process is our bodies’ natural response to foreign invaders (non-self).  (Of course, in the case of autoimmunity, our immune systems mistake our body tissues for a foreign invader.) These invaders can include chemicals, biological agents, but also, the failure to eliminate waste or undigested nutrients we’ve eaten.  Chronic inflammation, as you also know, can cause the breakdown of the integrity of the gut epithelial barrier, as well as the blood-brain barrier.  Once in the brain, proinflammatory molecules can trigger brain inflammation and “…pave the way to specific chronic neurodegenerative diseases.”

How your body deals with what you eat – which is, by its very nature foreign material, has a tremendous impact on the state of inflammation in the body and thus, with maintaining or harming the integrity of those two critical barriers.  The authors of this paper hypothesize that the attack on the blood-brain barrier is essentially autoimmune in nature:  molecular mimicry wherein one molecule greatly resembles another, which is thought to be the essence of autoimmunity, i.e. undigested food substances escaping the leaky intestinal barrier are very similar to certain brain proteins, together with the gut microbiota metabolites, lead to chronic inflammation.

Food, they point out, affects our health in two ways:  we require it for our own metabolism (upon which it obviously has huge impact) and it also influences the composition of the gut flora.  Only food that is fully digested (i.e. degraded to simple molecules which our bodies can actually use) are “congenial” to us.  Undigested food amounts to foreign substances which can evoke abnormal immune response:  “…the task of digestion is to make food like us, while absorption is required to make simple molecules available to our metabolism.  In just over a day (35-30 hours) our food becomes part of us.”

Think about that next time you chow down on junk food!

So here is a key points summary:

1. “It is therefore important to avoid or limit food and drugs that may loosen the integrity of the gut barrier, including persistent stressful situations, and to prefer dietary factors that may reinforce the integrity of the gut barrier.”
2. Disturbances of the gut barrier are confirmed to be a major factor in the development of a variety of illnesses, including autoimmune disease.
3. Factors known to damage the integrity of this barrier include “…Western diets, saturated fatty acids, gluten, salt, alcohol and chemical additives present in processed food.” Other factors include NSAIDS, other medicines, and stress.
4. Factors known to have a protective effect: calorie restriction/fasting, prebiotics, probiotics, butyrate, Vitamins D and A, flavonoids, omega 3, zinc.
5. Gut derived molecules which resemble brain proteins lead to the breakdown of the blood-brain barrier. Normally, only very specific kinds of molecules an pass through this barrier.  However, toxins from gut bacteria, including lipopolysaccharides from gram-negative bacteria and something called lipoteichoic acid from gram-positive bacteria, bind to certain receptors causing an inflammatory and “antigen-specific” (that is a response that is specific to a certain molecule) response. (Remember this post from last week on vascular brain diseases?!   Those with that vascular disease, (Cavernous angiomas) clearly had higher numbers of certain gram-negative bacteria and their toxins…)

Their conclusion:  which organ is specifically affected by autoimmunity, i.e. the brain versus the thyroid versus the cartilage, etc., is determined by the undigested food antigens present.  That is, “molecular mimicry” is key:  if the undigested food protein, from a compromised digestive process, which makes its way into the blood stream via the leaky gut, most resembles the tissue of, let’s say, the thyroid, this is the organ the body will attack.  For someone else though, who eats loads of a different food – with its undigested nutrients looking more like a brain protein – well, ALS or Parkinson’s is more likely.  And more than that:  by causing a sustained state of chronic inflammation – including neuroinflammation – these undigested food proteins can also “…alter synaptic connections and brain morphology with diverse modalities in different neurological disorders.”

How many times in these last years have I emphasized that the foundation of good health is a good diet?  Bearing in mind that it is likely the original source of disease and that you literally are what you eat, we should all be inspired to look at what we are eating with that much greater care.  After all, the chemicals in those Twinkies may look to your immune system an awful lot like your brain!

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[i] Riccio P, Rossano R. Undigested Food and Gut Microbiota May Cooperate in the Pathogenesis of Neuroinflammatory Diseases: A Matter of Barriers and a Proposal on the Origin of Organ Specificity. Nutrients. 2019;11(11):2714. Published 2019 Nov 9. doi:10.3390/nu11112714