There are over 10 quadrillion (that's 10,000,000,000,000,000) little critters living in your intestines. That's more bacteria then the cells in your body -- by a factor of 10 -- even more then the total number of stars in the Milky Way Galaxy!
"Basically, we are a walking bacterial colony," said Professor Jeroen Raes, one of the researchers involved in a landmark study recently published in Nature. (1) There are more genes in the flora of the intestinal system than the rest of our body -- so much more that they are now being called a "second genome."
These bacteria have a profound influence on human physiology, your immune system, your nutrition, and are crucial for human life. The health of your body and mind is largely tied to the health of your gut.
The over 400 species of bacteria that reside in our gut are normally maintained in an elegant balance of good and bad species. (2) When in perfect tune they synthesize and excrete vitamins, prevent colonization by pathogens (bad bacteria) through competition or inhibition (3), stimulate the development of certain tissues, stimulate the immune system, metabolize drugs, produce gut-nourishing short chain fatty acids, stimulate the production of natural antibodies and help maintain a healthy gut lining (whose size is the area of a tennis court and our bodies' biggest exposure to the toxins of the outside world). (4)
When out of balance they create an environment of putrefaction and fermentation. This is often called "dysbiosis." (5) Adverse effects of dysbiosis include: production of all kinds of toxic enzymes (some are neurotoxic and others lead to colon cancer), interference with absorption of nutrients, increase in gut wall inflammation leading to food allergies (6), inflammatory bowel disease, atopic eczema (7), arthritis (8), irritable bowel disease, obesity (9), autism AND can even cause personality changes (10) (11) such as:
- Paranoia
- Hostility
- Altered visceral perception of our surroundings (12)
- Aggressive behavior
Many factors can alter the balance of gut bacteria:
- Antibiotic use
- Physical and emotional stress 13 14
- Diet
The typical American meat-eating diet -- high in animal protein, refined carbohydrates and sugar -- may cause an unhealthy imbalance of gut flora and the production of toxic amines (one of the possible causes of macular degeneration).
On the other hand, a healthier diet -- more vegetables, fruits, complex carbohydrates and less animal protein. With such a diet, you may begin to feel happier, saner and more intelligent.
And now you -- do you want to avoid one of the emerging causes of both obesity and food allergies? Lower your risk of inflammatory bowel disease, irritable bowel disease, eczema, colon cancer (15) strengthen your immune system? All this while reducing any levels of paranoia or hostility (and retaining your Jon Stewart sense of humor).
You can maintain your healthy gut flora with these simple steps:
- Eat a low fat diet rich in vegetables, fruits and complex carbohydrates
- Limit consumption of animal protein
- Reduce sugar consumption
- Increase pre-biotic and probiotic intake
Probiotics are bacteria beneficial to our gut -- the most common are Lactobacilis and Bifidobacterium. Typically found in various dairy products such as yogurt and kefir. Also in some fermented foods such as sauerkraut.
If eating yogurt as a source of probiotics be sure that the pasteurization process takes place before the live cultures are added.
Prebiotics such as Inulin and FOS (fructooligosacharides) are assist in the growth and activity of probioitcs. Asparagus, onions, garlic and sunchoke root are naturally high in inulin and FOS.
It's all in your gut. Listen to your gut. Ten quadrillion critters can't be all wrong. Maintaining healthy gut bacteria can keep you from getting sick, from feeling irritable, and, even from acting, well, downright crazy. When they are in balance, you can be too.
References:
Nature 464, 59 (2010) A human gut microbial gene catalogue.
Barrie S, Pizzorno J, Murray M. Comprehensive Digestive Analysis. A Textbook of Natural Medicine. Elsevier 2000
Malageladia G, et al. Gut Flora in Health and Disease. Lancet 361:9356;512-9/
Guarner F, Malagelada JR. Role of bacteria in experimental colitis. Best Pract Res Gastroenterol 17(5):793-804
Barrie S, Galland L, Intestianl Dybiosis and the Causes of Disease
Lionetti P, Effect of diet in shaping gut microbiota. PNAS; Aug 2 2010
Dotterud K, et al. Probiotics to prevent allergic disease. Brit J Dermatol, 2010
Bernoist C, Mathis D. But-residing bacteria trigger Arthritis. Immunity, June 25 2010
Turnbaugh P, Gordon J. An obesity-associated gut microbiome. Nature 444; Dec 2006
Goldberg D. A psychiatric study of patients with diseaes of the small intestine. Gut, 1970:11;459-465
Sandler RH. Botte ER. Relief of Psychiatric symptoms after metronidazole therapy. Clin Infect Dis 2000 Jan;30(1):213-4
Rousseaux C, Thurus X. Lactobacillus modulates intestinal pain and induces opiod and cannabinoid reeptors. Nat Med 2006;13:35-37
Bailey M, Dowd S. Stressor Exposure Disrupts Commensal Microbial Populations. Inf and Immun April 2010; 78(4): 1509-19
Holdeman L. Good I. Human Fecal Flora: Variation and Possible Effect of Emotional Stress. App Env Microbiol Mar 1976;21(3):369-75.
Moore W, Holdeman L. Discussion of Current Bacterial Investigations of the Relationship between Intestinal Flora, Diet and Colon Cancer. Cancer Res 1975 Nov:35;3418-29