Short communicationsEffect of depolymerized sodium alginate on Salmonella Typhimurium infection in human enterocyte-like HT-29-Luc cells and BALB/c mice

- Alginate (HM-NA) is a highly viscous polysaccharide in brown algae.
- Depolymerized alginate (LM-NA) is less viscous with low molecular weight (∼50 kDa).
- Both alginates inhibited S. Typhimurium adhesion and invasion in HT-29-Luc cells.
- Both alginates (2%) in the diet suppressed S. Typhimurium infection in mouse liver.
- LM-NA (2.5%) drinking water inhibited S. Typhimurium infection in liver and spleen.

Depolymerized low-molecular-weight sodium alginate (LM-NA) has been developed as functional component for beverages. Solubility of LM-NA is far higher than that of general high-molecular-weight sodium alginate (HM-NA). To evaluate the effects of the alginates on infection of food related pathogens, the adhesion and invasion of Salmonella Typhimurium in human enterocyte-like HT-29-Luc cells and the infection in BALB/c mice were studied. Both the alginates (0.1% w/v) inhibited the adhesion and invasion in HT-29-Luc cells by 70-80%. Dietary intake of both alginates (2% w/v) reduced the infection in the liver of BALB/c mice from 5.0 to 4.4 log CFU/g tissue. Drinking water containing LM-NA (2.5% w/v) also reduced the infection in the liver from 5.5 to 4.6 log CFU/g tissue and in the spleen from 4.6 to 3.6 log CFU/g tissue. These results suggest that LM-NA can exert positive immunomodulatory effects and would be useful as a functional food material.