最近十几年来,由于厌氧菌分离和培养技术的发展,厌氧菌的检出率逐渐提高,国内外大量实验证明在健康人和动物体内不仅有需氧菌,也有大量的厌氧菌。以肠道菌群为例,其厌氧菌总数竞占细菌总量的95％以上,而需氧菌或兼性厌氧菌总和不超过5％。这就是为什么把正常菌群与厌氧菌联系在一起的原因。正常微生物群的定义早在本世纪20年代德国细菌学家就提出病理微生物和生理微生物的概念,但由于种种原 In recent ten years, due to the development of anaerobic bacteria separation and culture technology, the detection rate of anaerobic bacteria has gradually increased. A large number of experiments at home and abroad have proved that not only aerobic bacteria but also anaerobic bacteria are present in healthy humans and animals. Taking gut flora as an example, the total number of anaerobic bacteria occupies more than 95% of the total bacteria, while the sum of aerobic bacteria or facultative anaerobe does not exceed 5%. This is why the normal flora is associated with anaerobic bacteria. The Definition of Normal Microbiology As early as the 1920s, German bacteriologists proposed the concept of pathogenic microorganisms and physiological microorganisms. However,