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Related to normal flora: resident flora
nor·mal flor·a(nōr'măl flōr'ă)
The largest concentration of bacteria in humans is in the colon, where more than 400 genera may coexist. In the colon, anaerobic bacteria outnumber aerobic bacteria 1000:1, and there may be 1011 per g of fecal material. The anaerobic gram-positive lactobacilli may be concentrated in the vagina at the 105 to 108/ml level, but 20% of women have no detectable anaerobes in the vagina. In dental plaque and gingival sulci, the bacteria may reach a concentration of 1012/ml.