Altered microbial ecology in the gut may produce disease and dysfunction because of the intense metabolic activity and the antigenic nature of bacterial flora. Bacterial enzymes can degrade pancreatic enzymes, damage the intestinal absorptive surface, release toxins that had previously been bound by conjugation and alter the intestinal milieu in numerous ways, some of which can be easily measured in a properly collected sample of stool.
Based on available research and clinical data, there are four general causes of intestinal dysbiosis:
1) PUTREFACTION -dysbiosis results from diets high in fat and animal flesh and low in insoluble fiber. This type of diet produces an increased concentration of Bacteroides species and a decreased concentration of Bifidobacteria in the stool. It increases bile flow and induces bacterial urease activity. The change in composition of the gut flora leads to an increase in bacterial enzymes which, amongst other things, increases cancer causing substances and interferes with the body's hormones. As there is a decrease in friendly bacteria, the production of short-chain fatty acids and other benefical nutrients is decreased. There is also an increase in ammonia which can have negative effects on numerous bodily functions. Research has implicated this type of dysbiosis in contributing to colon cancer and breast cancer .
In cases of Putrefaction Dysbiosis, the alterations in bacterial population dynamics which result from this diet are measured by an increase in stool pH (partly caused by elevated ammonia production) and in bile or urobilinogen and possibly by a decrease in short chain fatty acids, especially in BUTYRATE.
2) FERMENTATION/SMALL BOWEL BACTERIAL OVERGROWTH (SBBO) - This is a condition of carbohydrate intolerance induced by overgrowth of bacteria in the stomach, small intestine and beginning of the large intestine. Bacterial overgrowth here is promoted by hypochlorhydria, by stasis due to abnormal bowel motility, physical /surgical abnormalities, by immune deficiency or by malnutrition. Gastric bacterial overgrowth increases the risk of systemic infection and the sufferer developes an intolerance to carbohydrate. Any carbohydrate ingested is fermented by the bacteria and results in production of toxic waste products.
Carbohydrate intolerance may be the only symptom of bacterial overgrowth, making it indistinguishable from intestinal candidiasis; in either case dietary sugars can be fermented to produce endogenous ethanol. Chronic exposure of the small bowel to ethanol may itself impair intestinal permeability. British physicians working with the gut-fermentation syndrome have tentatively concluded, based on treatment results, that the majority of cases are due to yeast overgrowth and about 20% are bacterial in origin. The symptoms include abdominal distension, carbohydrate intolerance, fatigue and impaired mental function.
3) DEFICIENCY - Exposure to antibiotics or a diet depleted of soluble fiber may create an absolute deficiency of normal fecal flora, including Bifidobacteria, Lactobacillus and E. Coli. Direct evidence of this condition is seen on stool culture when concentrations of Lactobacillus or E. Coli are reduced. This condition has been described in patients with irritable bowel syndrome and food intolerances. Deficiency and putrefaction dysbiosis are complementary conditions which often occur at the same time and call for the same treatment regime.
4) SENSITIZATION - Aggravation of abnormal immune responses to components of the normal
intestinal microflora may contribute to the development of inflammatory bowel disease, spinal arthritis, other connective tissue disease and skin disorders such as psoriasis or acne. The responsible bacterial components include toxins which can cross-react with human tissue.
COMPLICATIONS - Bacterial antigens may elicit dysfunctional immune responses which contribute to autoimmune diseases of the bowel and of connective tissue.
Reference : http://www.diagnose-me.com/symptoms-of/bacterial-dysbiosis.php