Bacteria in the resting zone

(A) Habitual colonic bacteria in the healthy wild-type mouse are diffusely distributed and have similar high concentrations at the center of stool and in the "germinal" zone indicating normal function of colonic bioreactor.
(B) Bacteria are suppressed in a 28-week-old mouse with IL-10 deficiency, at the center of stool, but are unchanged at the "germinal" zone. The reaction is general and is indicative for any disturbance of the colonic bioreactor. Bacteroides is orange, Eubacterium rectale is red, all other bacteria are green (x400). The suppression of bacteria precedes the inflammation. The animals had no symptoms.