Most of the bacteria that enter the stomach from the mouth are killed by gastric acid, and the rest are mainly Gram-positive aerobic bacteria. Bacterial concentration in stomach
The composition of small intestinal flora is between stomach and colon. The flora in the proximal small intestine is similar to that in the stomach, but Escherichia coli and anaerobic bacteria can often be separated. Between the terminal ileum and anaerobic.
The flora in the proximal small intestine is similar to that in the stomach, but Escherichia coli and anaerobic bacteria can often be separated.
At the end of ileum, the number of anaerobic bacteria began to exceed that of aerobic bacteria, among which Escherichia coli always existed, and there were quite a few anaerobic bacteria such as Bacteroides, Bifidobacterium and Clostridium.
The bacterial concentration in the distal ileocecal valve increased sharply, and the bacterial concentration in the colon was as high as10.1~10.12cfu/ml, and the total number of bacteria almost accounted for 1/3 of the dry weight of feces. Among them, anaerobic bacteria are 10.3 ~ 10.4 times that of aerobic bacteria. The main strains are fecal bacilli, bifidobacteria and eubacteria.