This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
The predominant colonic bacteria are 
Select and explain. 
A. Largely aerobic, B. Largely anaerobic, C. Bacteroides, D. Staphylococci
B: Largely anaerobic
Answer: B: Largely anaerobic 
Explanation: The normal flora of adult colon contains 96 to 99%anaerobess and only 1 to 4% of aerobs. Ref: Baveja textbook of microbiology; 4th edition. .