normal microbial flora of the intestine
In the jejunum of healthy people is up to 10 5 bacteria in 1 ml
intestinal contents. The bulk of these bacteria are streptococci,
staphylococci, lactic acid bacillus, and other gram-positive aerobic bacteria and fungi
. In the distal ileum the number of microbes increases
to 10 7 -10 8 , primarily due to enterococci,
Escherichia coli, Bacteroides, and anaerobic bacteria. Recently, we
found that the concentration of parietal microflora of the jejunum at 6 orders
higher than in its cavity, and is 10 11 cells / ml. About 50% of the biomass
parietal microflora are actinomycetes, approximately 25% - aerobic cocci
(staphylococci, streptococci, enterococci and korineformnye bacteria), from 20 to 30%
accounted for bifidobacteria and lactobacilli.
number of anaerobes (peptostreptokokki, bacteroides, clostridia,
propionobakterii) is about 10% in the fine and up to 20% in the colon. At
share enterobacteria accounts for 1% of the total microflora of the mucous membrane.
to 90-95% of microbes in the large intestine are anaerobes (bifidobacteria and bacteroides
), and only 5-10 % of all bacteria have a strict aerobic and
optional flora (lactobacilli and E. coli, enterococci,
staphylococci, fungi, Proteus).
Escherichia coli, Enterococci, Bifidobacteria and Lactobacillus acidophilus have
marked antagonist properties. In a well-functioning
intestine they are able to inhibit the growth of normal microflora
unusual microorganisms.
internal surface area of the intestine is about 200 m 2 .
It is reliably protected from penetration of food antigens, microbes and viasses.
an important role in this defense is the immune system.
About 85% of human lymphatic tissue is concentrated in the intestinal wall, where
produced secretory IgA. Intestinal microflora stimulates the immune defense.
Intestinal antigens and toxins of intestinal bacteria significantly increases the secretion of
IgA in the intestine.
splitting of undigested nutrients in the colon by bacterial enzymes
, forming a variety of amines, phenols,
organic acids and other compounds. Toxic products of microbial metabolism
(cadaverine, histamine and other amines) excreted in the urine and is normally not
effect on the body. When disposing of microbes
indigestible carbohydrates (fiber) produced short-chain fatty acids. They provide
gut cells energy and, consequently, improve the trophic
mucosa. With a deficit of cellulose can be broken
permeability of the intestinal barrier due to lack of short-chain fatty acids. As a result of intestinal
microbes can penetrate into the blood.
Under the influence of microbial enzymes in the distal ileum is
dekonyugatsiya bile acids and the conversion of primary bile acids into secondary
. Under physiological conditions, from 80 to 95% of bile acids
reabsorbed, and the rest are excreted in faeces in the form of bacterial
metabolites. Last contributes to the formation of feces:
inhibit the absorption of water and thereby prevent excessive dehydration of feces.
Dysbacteriosis
The concept of intestinal dysbiosis include excessive microbial colonization
small intestine and changes in microbial composition of the colon. Violation
microbiota occurs in varying degrees in most patients with pathology
intestines and other digestive organs. Consequently, dysbacteriosis
a bacteriological concept. It can be seen as one of
manifestations or complications of the disease, but not an independent nosological
form.
by extreme intestinal dysbiosis is the emergence of bacteria
the gastrointestinal tract into the blood (bacteremia) or even the development of sepsis.
composition of intestinal microflora is disturbed in diseases intestines and other digestive organs
, antibiotics and immunosuppressants,
effects of harmful environmental factors.
clinical manifestations of dysbiosis depend on the localization of dysbiotic
changes.
Dysbacteriosis small intestine
dysbacteriosis In the small intestine of some number of microbes in the mucous membrane of the small intestine
increased and others decreased . The increase
Eubacterium (30 times),