Biomedical subjects
Publications and source records attributed to Katsunori Kimura.
Twenty lactobacilli isolated from human feces were studied for binding to the human blood type B-antigen [Galalpha1-3 (Fucalpha1-2) Gal-] and H-antigen (Fucalpha1-2Gal-] expressed sugar chains in human intestinal mucosa. We found two strains, L. gasseri OLL2755 and L. gasseri OLL2877 that firmly adhere to human B-antigen, and we found L. gasseri OLL2827 bound to the H-antigen.
Adherent lactic acid bacteria (LAB) in the human intestine were investigated using the surface plasmon resonance technique with the biosensor BIACORE-1000. Ninety-three LAB strains were isolated from human feces and evaluated for binding to human blood type-A antigen [GalNAcalpha1-3 (Fucalpha1-2) Gal-: A-trisaccharide] expressed in the intestinal mucosa. Eleven strains showed strong adherence to an A-trisaccharide biotinyl polymer (BP) probe, and slightly or no adherence to a B-trisaccharide BP probe. Four strains with high adherence (high A/B ratio) were selected and their surface layer proteins (SLPs) were evaluated for A-antigen ligand binding using BIACORE. The SLP from L. brevis strain OLL2772 showed a single band at ca. 48 kDa by SDS-PAGE analysis and it had a very strong adherence to the human A-antigen, as shown using an anti-A lectin blocking technique. A partial N-terminal sequence of the band showed strong homology to an S-layer protein of L. brevis ATCC8287T. The probiotic LAB binds to human blood type-A antigen expressed in the intestinal mucosa which may aid in colonization of the gut.
Non-Helicobacter bacteria can be cultured from the gastric mucosa in adults but in children, there are no studies about such microflora. The purpose of this study, therefore, was to clarify whether gastric biota develops in children. In 10 children and 10 adults or elderly (5 H. pylori-infected and 5 uninfected in each group), biopsy specimens of the gastric antrum and corpus and gastric juice were studied for bacterial examinations and the data were compared between both age groups in relation to H. pylori status and luminal pH. Bacterial genera and species were analyzed using both culture and real-time polymerase chain reaction (PCR) with the 52 genus- and species-specific primer sets. Non-Helicobacter bacteria in the mucosa were cultured from all adult patients, whereas microorganisms were cultured in only one child (p < .001). Gastric pH was lower in children (median, 1.4) than in adults (median, 2.6) (p < .005). The grade of endoscopic gastric atrophy was moderate or severe in 8 adults, but absent or mild in all 10 children. Among adults, there was a significant positive correlation between gastric pH and total bacterial counts of both the mucosa and juice. These data indicate that impaired gastric acid secretion associated with long-term H. pylori infection enables non-Helicobacter bacteria to colonize in the human stomach. Such microorganisms rarely colonize in the gastric mucosa in children regardless of H. pylori status.