Table 2.

Distribution of normal gut flora in different parts of intestine

Intestine sections	Function	Normal flora
Stomach	Acid production, pepsin, amylase, CFU < 103/mL	Lactobacillus; Streptococcus; Helicobacter pylori
Small intestine: Duodenum, jejunum	Pancreatic enzymes, bicarbonate ions, bile salts, CFU: 103-104/mL	Lactobacilli; Enterococci, Streptococci; Actinobacteria
Small intestine: Ileum	CFU: 103-109/mL	Enterococcus; Bacteroidetes; Lactobacillus; Clostridium; Corynebacteria
Large intestine: Cecum, colon	Mucus and bicarbonate; CFU: 1010-1012/mL	Bacteroidetes; Clostridium; Eubacterium; Ruminococcus; Streptococcus; Enterococcus; Lactobacillus; Fusobacteria

CFU: Colony-forming unit.