Chitosan oligosaccharides generally refer to 2-20 units of oligosaccharides, produced by chitosan degradation, better water solubility than chitosan, can be directly absorbed by the human body, widely used in medicine, food, beverage, cosmetics, printing and other industrial fields. The inhibition of chitosan oligosaccharides on Helicobacter pylori was studied.
The results of different concentrations of chitosan oligosaccharides and the antibacterial circle of sugar raw materials showed that the chitosan oligosaccharides degraded by exonuclease or mixed enzyme had no antibacterial effect. its bacteriostasis ability is enhanced in the molecular weight range of 1.5 kD-10 kD with the decrease of molecular weight and with the increase of concentration. this is due to the fact that chitosan oligosaccharides with smaller molecular weight are more conducive to entering the cell interior, adsorbing the cytoplasm with anion in the cell body, and flocculating, disrupting the normal physiological activities of the cell and thus inhibiting its growth. However, the chitosan oligosaccharides degraded by exonuclease or mixed enzyme were absorbed as carbon source because of the large amount of monosaccharides. the results of the four shell oligosaccharides C3, C5, C6 and C7 obtained from endonuclease degradation under different ph conditions showed that the bacteriostatic effect of the four shell oligosaccharides was significantly enhanced with the decrease of pH value in the range of 1.90-3.86, and the bacteriostatic effect was more significant at pH1.90. because the normal pH of gastric contents varies from 1.35 to 2.65 day and night, this indicates that the acidic environment in the stomach is more conducive to the development of the bacteriostatic properties of chitosan oligosaccharides.