Why All the Emphasis on Digestion?
As a liver surgeon, Dr Bernhoft always considered the liver to be the “seat of the soul.” So much goes on in the liver – processing of food, removal of toxins, fighting against infection – that it is probably the only organ which could not be replaced with a machine. But the intestines are equally important. The surface area of the small intestine, alone, is roughly equal in size to a tennis court. It has more solid contact with reality (in the form of the pounds of material we ingest each day) than any other part of the body.
That being the case, the small intestine’s job is a very big one. It is responsible for letting useable parts of the food and drink we consume into our bodies, but also for keeping out toxic things we swallow. It does that by maintaining integrity at the cellular level. A food component, toxin, virus or bacterium which wishes to get into the body via the gut has to go through the cells lining the gut (enterocytes), or through the “tight junctions” between enterocytes.
As long as the tight junctions stay tight, things function reasonably well. But if the junctions become leaky (so-called “leaky gut”), as can happen with excessive antibiotic use, ingestion of toxic chemicals (including low doses of toxic chemicals adding up over a long time), or various types of infection, people get sick. Various inappropriate materials (partially-digested food, viruses and other pathogenic bugs or chemicals) can be absorbed, to our peril1.
When these foreign materials invade the blood stream, bad things happen. The immune system sees them as foreign, and attacks. Sometimes it also attacks cells in the body with surfaces similar to the foreign materials. This can produce allergies, arthritis, odd neurological and psychiatric symptoms and a host of other problems.
Once the gut becomes leaky, it tends to remain so without treatment.
Treatment involves avoiding irritating foods and materials from the diet, replacement of specific amino acids which help the gut lining cells regenerate, repletion of favorable bacteria (probiotics) and their preferred foodstuffs (prebiotics). Sometimes it may take complete bowel rest with elemental or IV nutrition, but it can be done.
Once the gut regains its integrity, many other problems will often right themselves spontaneously, or with a little help. Restoration of gut integrity is usually required for other treatments – removal of heavy metals, balancing of hormones, relief of allergies – to respond effectively.
That’s why we put so much emphasis on digestion.
Selected References:
- DeMeo, MT et al, Intestinal permeation and gastrointestinal disease. J Clin Gastroenterol. 2002; 34:385-96.
- Musrat A, et al. Molecular physiology and pathophysiology of tight junctions IV. Regulations of tight junctions by extracellular stimuli: nutrients, cytokines and immune cells. Am J Physiol Gastrointest LIver Physiol. 2000; 279:G851-7.
- Gardner M. Gastrointestinal absorption of intact proteins. Ann Rev Nutr. 1988; 8:329-50.
- MacFie J, et al. Enteral versus parenteral nutrition: The significance of bacterial translocation and gut-barrier function. Nutrition 2000;16:606-11.
- Heine RG. Pathophysiology, diagnosis and treatment of food protein-induced gastrointestinal diseases. Curr Opin Allergy Clin Immunol. 2004; 4:221-9.
- Fink JP. Intestinal epithelial hyperpermeability: update on the pathogenesis of gut mucosal barrier dysfunction in critical illness. Curr Opin Crit Care. 2003; 9(2):143-51.
- De Giorgio R, Guerrini S, Barbara G, et al. Inflammatory neuropathies of the enteric nervous system. Gastroenterology. 2004; 126(7): 1872-83.
- D’Eufemia P, Celli M, Finocchiaro R, et al. Abnormal intestinal permeability in children with autism. Acta Paediatr. 1996:85:1076-79
- Rooney PJ, Jenkins RT, Buchanan WW. A short review of the relationship between intestinal permeability and inflammatory joint disease. Clin Exp Rheumatol. 1990; 8(1): 75-83.
- Wakefield AJ, Anthony M, Murch SH, et al. Enterocolitis in children with developmental disorders. Am J Gastroenterol. 2000; 95: 2285-95.
- Kruidenier L, Kuiper I, Lamers CB, et al. Intestinal oxidative damage in inflammatory bowel disease: semi-quantification, localization and association with mucosal antioxidants. J Pathol. 2003; 201:28-36.
- Blumgart DC et al. Intestinal barrier function. Curr Opin Clin Nutr Metab Care. 2002; 5:685-94.
- Kalliomaki M, et al. Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial. Lancet. 2001; 357(9262)1076-9.
- Isolauri E. Probiotics in human disease. Am J Clin Nutr. 2001; 73(Suppl):1142S-46S.
- Duggan C, et al. Protective nutrients and functional foods for the gastrointestinal tract. Am J Clin Nutr. 2002; 75(5): 798-808.