Prevention of chronic gastritis by fermented milks made with exopolysaccharide-producing Streptococcus thermophilus strains

Light micrographs (original magnification 1,000×) of hematoxylin-eosin stained mouse gastric mucosa belonging to different experimental groups: A) healthy group (H); and B) gastritis group (G), which shows lymphocytes and macrophage infiltration in the superficial mucosa.

Effect of preventive treatments with different fermented milks or exopolysaccharide suspension from Streptococcus thermophilus CRL 1190 and oral administration of acetyl-salicylic acid on the number of A) IL-10⁺- and B) IFN-γ⁺-producing cells on histological slices of mice stomachs; i) preventive treatments on gastritis, and ii) control groups without gastritis induction. Results are presented as means of 3 determinations and are expressed as the number of IFN-γ and IL-10-producing cells per 10 fields (original magnification 100×). *P<0.05 compared with the controls.

Histopathological inflammation score of healthy control group (H); gastritis group (G); and mice preventively treated for gastritis induced by acetyl-salicylic acid: milk group (M-ASA); artificially acidulated milk group (AM-ASA); fermented milk with Streptococcus thermophilus CRL 728 group (FM 728-ASA); fermented milk with Strep. thermophilus CRL 804 group (FM 804-ASA); fermented milk with Strep. thermophilus CRL 1190 group (FM 1190-ASA); exopolysaccharide produced by Strep. thermophilus CRL 1190 dissolved in milk group (M-EPS 1190-ASA); exopolysaccharide produced by Strep. thermophilus CRL 1190 dissolved in water group (W-EPS 1190-ASA). Data are expressed as means±SD.

Light micrographs (original magnification 100×) of hematoxylin-eosin stained gastric mucosa of mice preventively treated on gastritis induced by acetyl-salicylic acid (ASA). Determinations were done at d 18. A) milk group (M-ASA), B) artificially acidulated milk group (AM-ASA), C) fermented milk with Streptococcus thermophilus CRL 728 group (FM 728-ASA), D) fermented milk with Strep. thermophilus CRL 804 group (FM 804-ASA), presenting chronic inflammatory infiltration in mucosa's surface, E) fermented milk with Strep. thermophilus CRL 1190 group (FM 1190-ASA), F) exopolysaccharide produced by Strep. thermophilus CRL 1190 dissolved in milk group (M-EPS 1190-ASA) showed conserved histological structure similar to the control (H), and G) exopolysaccharide produced by Strep. thermophilus CRL 1190 dissolved in water group (W-EPS 1190-ASA) displayed chronic inflammatory infiltration.

Effect of preventive treatments with different fermented milks, EPS 1190 and oral administration of acetyl-salicylic acid (ASA) on periodic acid-Schiff-positive mucus on the mice gastric mucosa. Original magnification=400×. A) Thickness ratio of the mucus gel layer to the lamina propria mucosae in corpus and antrum mucosa. Values represent means±SEM for 5 mice. *P<0.05 compared with the healthy group (H). **P<0.05 compared with the gastritis group (G). B) Representative photomicrographs of corpus mucosa from H, G, M-ASA, AM-ASA, FM 728-ASA, FM 804-ASA, FM 1190-ASA, M-EPS 1190-ASA, and W-EPS 1190-ASA. Sections were stained using periodic acid-Schiff reagent.