Healing the Gut + Autoimmunity

Leaky Gut > Immune Response = Autoimmunity

In leaky gut syndrome, the tight junctions of the intestinal epithelial lining loosen, allowing harmful substances like bacteria, toxins and undigested food particles to enter your bloodstream and thus inducing the autoimmune response(4). Thus, leaky gut syndrome is believed to be linked to various conditions, including a wide range of autoimmune diseases, migraines, autism, food sensitivities, skin conditions, brain fog and chronic fatigue(5). 

How Leaky Gut Leads to Autoimmunity + Damage

Once your gut barrier is “leaky” and toxins, viruses, bacteria and food particles flood your bloodstream, the immune system marks them as dangerous invaders and initiates the immune response, causing inflammation in an attempt to get rid of them. As the gut barrier disintegrates and more particles escape into your bloodstream, your immune system responds with wave after wave of inflammation. Eventually it becomes over stressed and begins firing less accurately. This in turn leads to autoimmunity, as your own tissues end up in the crossfire. What’s more, many of the particles that are now flooding your bloodstream look a lot like your body’s own tissues (self-antigens). Your immune system will then create antibodies against these substances which mistakenly attack your tissues in the process, in a phenomenon called molecular mimicry.

“All Disease Begins in the Gut”

Was Hippocrates right in saying this 2,000 years ago? The truth is, he was more right than he could know. Method and evidence-based science is now proving that gut health is everything.

The gut is the largest and most dynamic immunological environment and organ within the body. “Indeed, gut-associated lymphoid tissue (GALT) is the prominent part of mucosal-associated lymphoid tissue (MALT) and represents almost 70% of the entire immune system; moreover, about 80% of plasma cells [mainly immunoglobulin A (IgA)-bearing cells] reside in GALT.”(6). Thus, 80% of the immune system resides in the gut, lending meaning to the saying “All disease begins in the gut. This is less surprising when you learn that the ‘gut immune system’ has a surface area equivalent to that of a small studio flat (100-130 square feet) and that the gut is the largest part of our digestive system, measuring at 12 feet in length. 

The Gut Barrier

The gut barrier is a functional unit, organised as a multi-layer system, made up of two main components: a physical barrier surface (the gut barrier), which prevents bacterial adhesion and regulates paracellular diffusion to the host tissues - thus acting as a first-line defense against outside microbe threats - and a deep functional barrier, that is able to discriminate between pathogens and commensal microorganisms (such as bacteria), regulating the immune tolerance and the immune response to pathogens.Thus these two gut variables - the intestinal microbiota and the gut barrier - form an immunological barrier and physical barrier which determines the health of the gut and consequently, overall human health(7). 

Why Healing Autoimmunity + the Gut Are Linked

We delve into the vital importance of the microbiome and its profound influence on human health on the Nature + the Microbiome page, but here’s a few nuggets of info demonstrating the hand-in-hand relationship between the gut and immune system, and why healing the gut and autoimmunity are linked -

1. Maternal bacteria teach the immune system how to behave. Microbiota begin to exert their influence on our lives even before we are born, playing a role in immune development while we are floating in our mothers’ wombs; antibodies that potentially retain microbial molecules are transmitted to the offspring during pregnancy(8). In this way, bacteria present in the placenta of mammals educate the naive, young immune system so it can learn how to protect the body from harm when the maternal antibodies are no longer there(9)
2. Bacteria educate our immune system from the moment we are born. Immature immune systems lack important types of immune cells, but in the presence of even a restricted bacterial flora, the immune system matures and develops a more diverse range of cells. We know that children born from caesarean section have a far higher risk of developing certain diseases – some studies show as much as 20% higher risk of type 1 diabetes, asthma, and an increased risk of obesity, compared to vaginally born children, who are covered in their mother’s microbiome upon entry into the world. This more sterile method of delivery, delays the colonisation of gut bacteria and thus too, the education of the immune system(9)
3. Gut bacteria maintain a functional and balanced immune system. An essential task of the immune system is to maintain a balance between reaction and tolerance - otherwise, every time we are exposed to something new in our gut, nose and lungs, via our food and environment, such as a food, pollen or non-pathogenic microorganisms in dust or dirt, an inflammatory response would be triggered, wasting the body’s vital energy and resources. Since the balance of bacteria in our gut influence the balance of our immune system, an unbalanced microbiome with too many opportunistic pathogenic bacteria (e.g. SIBO) can shift the immune system to an increased inflammatory state, and result in a “leaky gut”. This inflammatory state may then affect other body systems and increase the risk of obesity, type 1 and type 2 diabetes and even depression(9).

Treating SIBO is separately discussed on the Healing SIBO page.