| abstract |
Provided is an isolated B. fragilis bacterial cell producing a native capsular polysaccharide A (PSA), wherein the cell is incapable of producing capsular polysaccharides PSB, PSC, PSD, PSE, PSF, PSG, and PSH because the cell's biosynthetic genes for native capsular polysaccharides PSB, PSC, PSD, PSE, PSF, PSG, and PSH have been deleted from the cell's genome. The isolated or wild type B. fragilis cell, or an extract obtained from said B. fragilis cell, can be used to treat individuals with inflammation. |