The gastrointestinal tract of healthy people is inhabited by a wide variety of microorganisms, which are called intestinal flora. Once the internal and external environment of the body changes, especially the long-term application of broad-spectrum antibiotics, sensitive intestinal bacteria are inhibited, and the uninhibited bacteria multiply, thus causing dysbiosis, and the normal physiological combination is destroyed, and the pathological combination, causing clinical symptoms is called intestinal The clinical symptoms are called intestinal flora dysbiosis.
Etiology: 1, dietary factors: diet can cause significant changes in the fecal flora. Fiber-free food promotes bacterial translocation. Fiber can maintain the normal metabolism and cellular dynamics of the intestinal mucosa cells. Food fiber can reduce bacterial translocation, but can not make the barrier function back to normal.
2, the change factors of the bacterial flora: 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 fairly long period of time. The ecological status of each strain is determined by the physiological state of the host, the interaction between bacteria and the influence of the environment.
3, the metabolic factors of drugs: intestinal flora plays an important role in the metabolism of many drugs, including lactulose, salicylic acid azo sulfadiazine pyridine, levodopa, etc.. Any antibiotic can lead to changes in the intestinal flora, which depends on the antibacterial spectrum of the drug and its concentration in the intestinal lumen. Clindamycin and ampicillin, among others, tend to cause dysbiosis, which results in the proliferation of drug-resistant Clostridium difficile and causes antibiotic-associated diarrhea (pseudomembranous enteritis). Application of H2-receptor antagonists such as metformin can lead to drug hypogastric acidity and bacterial proliferation in the stomach.
4, age factors: as age increases, the balance of intestinal flora can be changed, bifidobacteria decreased, the aerobic bacillus increased, the former may weaken the stimulation of immune function, the latter leads to increased toxins so that immunity is suppressed. If the elderly can maintain the balance of intestinal flora when they were young, they may be able to improve immunity.
5, gastrointestinal immune dysfunction: The normal immune function of the gastrointestinal tract comes from the plasma cells in the lamina propria of the mucosa, which can produce a large amount of immunoglobulin, i.e. secretory IgA, the main substance of the gastrointestinal tract to prevent bacterial invasion. Once the mucosa of the gastrointestinal tract synthesizes monomeric or bimodal IgA, or the synthesis and secretion of the sheet is impaired, resulting in the lack of fractional IgA in the secretory fluid of the gastrointestinal tract, it can cause overgrowth of aerobic and anaerobic bacteria in the small intestine, resulting in dysbiosis and chronic diarrhea. In asymptomatic IgA deficient patients, the small intestine flora can also overgrow. The higher incidence of dysbiosis in the neonatal period may also be related to the immature or imperfect development of the immune system.