Gut flora disorder
Introduction
Introduction to intestinal flora disorders A healthy person has a wide variety of microorganisms in the gastrointestinal tract. These microorganisms are called intestinal flora. The intestinal flora is combined in a certain proportion, and the bacteria are mutually restricted and interdependent, forming an ecological balance in quality and quantity. Once the environment changes inside and outside the body, it is characterized by long-term application of broad-spectrum antibiotics, and sensitive intestinal bacteria are inhibited. The uninhibited bacteria multiply and multiply, causing the flora to be dysfunctional, and its normal physiological combination is destroyed, resulting in a pathological combination, causing clinical symptoms called the intestinal aberration syndrome (alterationofintestinaflora). The incidence of this disease is about 2% to 3%. basic knowledge The proportion of illness: 10% Susceptible people: no specific population Mode of infection: non-infectious Complications: malnutrition food poisoning diarrhea diabetes
Cause
Causes of intestinal flora disorders
Dietary factors (25%):
Using the method of measuring bacterial enzymes to study the metabolic activity of the flora showed that the diet can make a significant change in the fecal flora, and the fiber-free food can promote the bacterial translocation. SpaethG is used in rats for experimental research, and the results show that the dietary fiber can maintain the intestine. The normal flora of the flora is balanced, and the end products of the bacterial metabolism fiber have a nutritional effect on the intestinal epithelium. The fiber can maintain the normal metabolism and cell dynamics of the intestinal mucosa cells. Hosoda et al reported that the low-slag diet of the fiber is added to preserve the structure of the intestine. The function has a good effect. Whether the protective effect of fiber directly stimulates the intestinal mucosa or induces the release of nutritive gastrointestinal hormone is not clear. The dietary fiber can reduce the bacterial translocation, but can not restore the barrier function to normal.
Factors that change the flora (20%):
The composition of the flora can vary from individual to individual, but for the same person, the composition of the flora is very stable over a long period of time, and the ecological status of each species is determined by the physiological state of the host, the interaction between bacteria and The influence of the environment determines that all ecological status is occupied under equilibrium, and the temporary habitat of bacteria can change the ecological balance.
Metabolic factors of the drug (18%):
Intestinal flora plays an important role in the metabolism of many drugs, including lactulose, sulfasalazine salicylate, levodopa, etc. Any antibiotic can cause changes in the colonic flora, depending on the antibacterial spectrum of the drug and Its concentration in the intestinal lumen, clindamycin and ampicillin can cause an ecological vacuum in the large intestine, allowing C. difficile to proliferate, and the use of H2-receptor antagonists such as cimetidine can lead to drug-induced low acid and Proliferation of bacteria in the stomach.
Age factor (15%):
With the increase of age, the balance of intestinal flora can be changed, the double-tailed bacteria is reduced, and the production of Clostridium perfringens is increased. The former may weaken the stimulation of immune function, and the latter cause the increase of toxin to inhibit immunity. If you can maintain the balance of intestinal flora when you are young, you may be able to improve your immunity.
Gastrointestinal immune dysfunction factors (10%):
The normal immune function of the gastrointestinal tract comes from the plasma cells of the lamina propria. The plasma cells can produce a large amount of immunoglobulin, the secretory IgA, which is the main substance that prevents the invasion of bacteria in the gastrointestinal tract. Once the gastrointestinal mucosa synthesizes monomers, Or double-body IgA, or the function of synthetic secretory tablets, resulting in the lack of typing IgA in the gastrointestinal secretions, can cause over-reproduction of aerobic and anaerobic bacteria in the small intestine, resulting in dysbacteriosis, causing chronic diarrhea, no In patients with IgA deficiency, the intestinal flora can also overproduce, and the incidence of dysbacteriosis in the neonatal period is high, which may be related to the immature or imperfect development of the immune system.
(1) excessive growth of bacteria: anatomical and physiological abnormalities of the gastrointestinal tract will lead to the proliferation of colonic plexus in the proximal small intestine, and various metabolic disorders, including steatorrhea, vitamin deficiency and carbohydrate malabsorption, may occur in the small intestine Pseudo-obstruction, scleroderma, diabetic autonomic neuropathy, chronic malnutrition, etc., bacterial growth in the small intestine, a variety of anaerobic bacteria (mainly Bacteroides, Bifidobacterium, Veillonococcus, Enterococcus and Clostridium can hydrolyze and bind bile salts, leading to microcapsule formation disorders, cirrhosis, low acidosis without obvious metabolic disorders, etc. Changes in colonic flora can lead to D with neurological insufficiency after extensive small bowel resection - Lactic acidosis, the use of broad-spectrum antibiotics, especially clindamycin and ampicillin can proliferate C. difficile, produce a proteinmycin, causing colonic mucosal necrosis and ulcers, known as pseudomembranous colitis.
(2) Bacterial production of IgA-degrading enzymes: hemolytic streptococcus, green streptococci, Streptococcus pneumoniae, Haemophilus influenzae, meningococcus, gonococcus, etc. can produce proteases that decompose IgA, and can decompose humans IgA1 in serum and secretory IgA in colostrum, of which the first 2 bacteria are the main species that constitute the oral flora, and the latter 4 are the virulence pathogens that adhere to the mucosal surface. It can be seen that IgA protease is essential for the survival or pathogenesis of these bacteria on the mucosal surface as a resident microorganism.
(3) Intestinal plexus and tuberculosis: The colonic flora produces a variety of metabolically active enzymes that mediate the reaction of some natural products, food preservatives, dyes, additives and pollutants into mutagenic substances, many bacteria The activity of the bacterial enzyme system can be increased due to prolonged exposure to the substrate. If the substrate is a procarcinogen, prolonged exposure can increase the production of carcinogens.
Prevention
Intestinal flora imbalance prevention
Rational use of antibiotics. For elderly frail and chronic wasting diseases, when using antibiotics or hormones, strictly control the indications. It is best to use drug sensitivity tests and select the most sensitive antibiotics. For those who are old, thin and infirm, use antibiotics together with lactobacillus or Bifidobacterium live bacteria preparations and vitamin B or vitamin C to prevent intestinal flora imbalance.
Complication
Intestinal flora disorder complications Complications, malnutrition, food poisoning, diarrhea, diabetes
Often complicated by indigestion, malnutrition, food poisoning, summer diarrhea in infants and young children, diabetes, acute necrotizing tumors, wasting diseases, malignant tumors, toxemia, and even shock.
Symptom
Symptoms of intestinal flora disorders Common symptoms Diarrhea, abdominal pain, nausea, vomiting, abdominal pain, loose stool, abdominal distension, belching, dyspepsia, blood pressure, fungal infection, stool, soreness
This disease is mainly caused by severe diarrhea or chronic diarrhea. In the course of antibiotic treatment, such as sudden onset of diarrhea, or the original diarrhea is aggravated, it may occur. The diarrhea is mostly yellowish green watery stool, sometimes Egg pattern, fungal infection can be foamy, loose, smelly, pus and bloody; staphylococcal infection can be yellow and green loose, 3 to 20 times a day, accompanied by abdominal distension, abdominal pain is generally not, vomiting and diarrhea can be severe Accompanied by dehydration, electrolyte imbalance, blood urea nitrogen increased, blood pressure decreased; Candida albicans infection generally begins from the upper digestive tract and spreads to the small intestine or even the perianal area. Thrush is often the earliest signal of Candida albicans enteritis, such as small intestinal mucosa Erosion or ulcer can cause multiple odorless mucus purulent feces, sometimes with watery diarrhea, accompanied by indigestion, such as treatment is not timely, can spread to the respiratory tract, urinary tract and even brain tissue; Pseudomonas aeruginosa infection can produce blue-green Fluorescein causes the feces to be green, but it does not often cause diarrhea. In some cases, there is powder in the feces, and the abdominal pain is light. A few have nausea, vomiting, water, electrolyte imbalance. In severe cases, shock can occur. Some tourists may suffer from intestinal flora imbalance due to changes in climate and environment. In recent years, due to the widespread use of refrigerators, some families store large amounts of meat and sparsely. Storage causes the food to deteriorate. After eating, it causes intestinal flora imbalance, causing vomiting, diarrhea, mental discomfort and even mental paralysis.
The types of clinical common intestinal flora disorders are as follows:
1, Candida albicans: is the most common type of intestinal flora disorders, more common in thin infants, indigestion, malnutrition, diabetes, malignant tumors, long-term use of antibiotics or hormones in patients.
2, staphylococcal enteritis: more common in long-term application of antibiotics (tetracyclines, ampicillin, etc.), adrenal cortical hormone and elderly patients with intestinal surgery or chronic disease patients.
3, Clostridium perfringens acute necrotic enteritis: -mycin produced by Clostridium perfringens can cause acute necrotizing tumors, wasting diseases, and the most prone to infections when using antibiotics, corticosteroids, etc.
4, Pseudomonas aeruginosa intestinal infection: Pseudomonas aeruginosa is a conditional pathogen, often secondary infection, in infants, the elderly, some malignant tumors, wasting diseases, and the use of antibiotics, corticosteroids, etc. An infection has occurred.
5, Proteus enteroinfection: Bacterium can be a conditional pathogen under certain conditions, such as common bacilli, singular bacillus, Proteus mirabilis can cause food poisoning, no permanent Proteus can cause infantile summer diarrhea.
6, enterobacteria enteroinfection: When the body's resistance is reduced or other reasons, normal parasitic bacteria in the intestinal tract can cause infection, especially in children with severe diarrhea.
Examine
Examination of intestinal flora disorders
First, the flora analysis: for the main inspection methods, there are two types of qualitative analysis and quantitative analysis.
1. Qualitative analysis: same as general microbiological examination, such as staphylococcal smear smear Gram stain can find piles of positive grape balls and neutral polymorphonuclear cells, feces culture can have a large number of staphylococcus growth, white rosary Bacterial enteritis can be directly smeared with its pathological material, treated with potassium hydroxide solution and Gram stain, microscopic examination can be seen clustered oval white Candida, Gram stain positive, intracellular coloration uneven, bacteria Culture can form a creamy surface with a smooth bacterial surface with a yeast odor, but except for the three-degree imbalance (ie, flora alternation) can be detected, other proportions are difficult to analyze, so in addition to qualitative examination, Further quantitative examination is required to determine whether the value is normal.
2. Quantitative examination: Firstly, the faeces should be homogenized and diluted according to a certain ratio. After the culture, the counts of various cell colonies must be calculated to determine the total number of bacteria. The procedure is troublesome, and the general laboratory rarely uses the normal flora. The medium used for the analysis is required to have a high degree of selectivity, such as S medium for intestinal pathogens, eosin blue medium for intestinal aerobic Gram-negative bacilli, 7.5% sodium chloride agar versus grapes Cocci, less Bow's agar on fungi, etc. In addition to aerobic culture, culture methods require anaerobic culture, aerobic culture is the same as general bacterial culture, and anaerobic culture uses biological anaerobic or anaerobic tank method.
Second, colonoscopy: intestinal mucosa is diffuse hyperemia, edema, vascular branches are blurred or disappear, there are scattered erosion ulcers and bleeding, sometimes visible yellow pseudomembrane adhesion.
Diagnosis
Diagnosis and identification of intestinal flora disorders
diagnosis:
Can be diagnosed based on clinical performance and laboratory tests.
Differential diagnosis:
The disease needs to be distinguished from diarrhea caused by other causes, and the bacterial culture can identify the types of intestinal pathogenic bacteria.
Diarrhea is a common symptom, commonly known as "diarrhea", which means that the frequency of bowel movements is significantly higher than the frequency of usual habits. The faecal is thin, the water is increased, the daily defecation is more than 200g, or contains undigested food or pus and mucus. Diarrhea is often accompanied by symptoms such as urgency of bowel movements, anal discomfort, and incontinence. Diarrhea is divided into acute and chronic. The incidence of acute diarrhea is acute, and the course of disease is within 2 to 3 weeks. Chronic diarrhea refers to recurrent diarrhea with a course of disease of more than two months or intermittent within 2 to 4 weeks.
