Have you ever heard of leaky gut? I know most haven’t. When I was working on the book The Complete Leaky Gut Health & Diet Guide , people would just stared back at me with a blank look on their faces whenever I told them what the book was about. This isn’t surprising because leaky gut has never been seen as a real medical issue for the most part by mainstream medicine except in some very specific cases such as Celiac disease or inflammatory bowel disease like ulcerative colitis and Crohn’s.
In the so-called ‘alternative’ health world however, leaky gut has always been taken seriously and seen as a major contributor to many different states of poor health including most to all auto-immune diseases. While not the source of all human ills and woes like many naturopathic doctors and holistic nutritionists suggest it is, leaky gut can, and is, an important player in several diseases and poor health.
Gut health – a new objective in medicine?
‘Gut health’ is an increasingly popular expression in every day language, the marketing of foods & supplements and it even shows up in the medical literature. Gut health is a broad term and is used in a generic way to talk about everything from the presence/absence of diseases of the gastrointestinal (GI) tract, mood as it relates to the role of gut health on psychological well-being, intestinal function such as digestion and elimination, and the state of our microbiota (the bacteria that live in our gut).
In scientific terms, gut health is somewhat unclear, hard to define and difficult to quantify, but one thing is for sure, achieving and maintaining overall gut structure & function is fast becoming recognized as desirable goal when it comes to improving overall health, and possibly preventing and treating many diseases that are clearly influenced and associated with the gut/GI tract. As an example, this recent study has linked gut health/gut bacteria to chronic fatigue syndrome, once thought to be solely psychological issues.
Leaky Gut 101
Leaky gut and leaky gut syndrome (LGS) simply put is an increase in intestinal permeability, or in other words, molecules like food proteins, bacteria, viruses, and other toxins that are normally prevented from entering are able to pass through the digestive tract’s defenses and enter the bloodstream. Under normal circumstances, the lining of the intestines (a single layer of cells called enterocytes), effectively control the transportation (through the cells themselves, in a very controlled manner – a process referred as ‘transcellular transportation’ – image A below) of small molecules such as water, amino acids, vitamins, electrolytes etc. and allows them to enter the bloodstream.
Normally only those molecules that the cell permits to enter the bloodstream are allowed through but under certain circumstances , larger molecules (food proteins, microorganisms, toxins etc) that are normally blocked, manage to slip through the gates (tight junctions) in between the cells; this is referred to as ‘paracellular transportation’ (image B below) a.k.a. ‘leaky gut/leaky gut syndrome’ and it’s not a good thing
In order to breach the tight junctions, some kind of trigger needs to be present which typically causes and perpetuates gut inflammation. A similar process happens with other barriers such as the skin; whether there is physical damage to the skin with an abrasion or chemical irritant, the skin becomes damage, inflammation follows and the barrier breached creating a free pass of bacteria etc. into the blood stream. Research has shown these unwanted visitors to be strongly associated with disease and/or symptoms such as fatigue, gas, bloating, skin rashes like eczema and psoriasis, joint and muscle aches, aggravation of autoimmune diseases, low grade inflammation throughout the body and more.
Chicken or egg
The tricky part with LGS is that it’s not straightforward. Gut inflammation and LGS has been shown to be predictors of future disease, but on the other hand, many diseases such as Celiac or IBD are known to increase intestinal permeability making it difficult to know when LGS is the cause or the result of disease; the answer is probably a little from column A and a little from column B. Regardless, LGS is becoming increasingly seen as its own true diagnosis but it’s premature to blame it on every ill known to humanity which many in the ‘alternative’ health camp do.
What we do know
Via clinical research, LGS has been shown to clearly exist and is found more so in certain diseases than in healthy controls (those without disease to serve as a comparison). Most of LGS research has used one of two tests; 1] the lactulose-mannitol test which involves consuming a solution with these two sugars followed by a urine collection and analysis over the following 6 hours. Lactulose is normally not absorbed and therefore doesn’t appear in the urine; if it does, it’s been absorbed through the small intestines via a breakdown with the tight junction, and filtered by the kidneys, and 2] the 51-Cr-EDTA test which also involves drinking a solution which contains radio-labelled chromium allowing for the accurate detection of it in the urine. Like lactulose, Cr-EDTA should not normally appear in the urine; if it does, leaky gut is present.
Contributors to leaky gut syndrome
The following have been shown to increase the likelihood of LGS:
- Enteric bacteria like salmonella
- Gluten (even in non-Celiacs)
- Radiation & chemotherapy
- Non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, indomethacin, ASA or ‘aspirin’)
- Infections (viruses, parasites, rotavirus, cryptosporidium)
- Systemic inflammation
Medical conditions associated with leaky gut syndrome
- Type 1 diabetes
- Celiac disease, Crohn’s & ulcerative colitis
- Autoimmune diseases (multiple sclerosis, rheumatoid arthritis, lupus, ankylosing spondylitis etc.)
- IBS & small intestinal bacterial overgrowth (SIBO)
- Food allergies & intolerances
- Cancers (brain [gliomal], breast, lung, ovarian, pancreatic)
- Obesity-related insulin resistance
LGS has been found to exist in all of these health conditions to some degree and in many cases, found to be present several years before their diagnosis. In this sense, LGS can be, and is, a predictor of disease, a comorbidity [co-illness] and contributor to poorer disease management. While not all patients with these diseases will have LGS, a large percentage of them may. For many who continue to feel unwell, or at least not as good as they think they could, and who are not satisfied by being told there’s nothing more that can be done, may want to seek out the support of a practitioner who takes a more functional approach.
Dietitians, integrative and functional nutritionists and other health professionals working with patients should stay on top of the latest research as it relates to LGS and other disease states while considering the presence of LGS as a possible variable in the patients’ care and work with the current evidence as it relates to different diets, supplements and lifestyle to help patients manage their health in a way that is safe, within scope and not contraindicated.