Inside a sick patient, antibiotics wipe out infectious bacteria by the millions.

抗生素消灭了患者体内几百万的传染性细菌。

This lab belongs to Alexander Fleming, a Scottish scientist investigating the properties of infectious bacteria.

该实验室属于亚历山大·弗莱明（Alexander Fleming），他是苏格兰科学家，负责研究传染性细菌的特性。

This infectious bacterium forms spores in the colon that are immune to antibiotics and very difficult to destroy.

这种具备传染性的细菌在结肠中形成对抗生素免疫且难以消灭的芽孢。

Even though mucus protects against the infectious bacteria, the vast majority of your body's bacterial tenants are not harmful, and many are actually beneficial.

尽管黏液保护我们不受细菌感染，你身体中大多数的细菌其实是无害的，甚至很多是对人体有益的。

In fact, some of the most toxic substances we know of are membrane-breaching proteins made by infectious bacteria.

事实上，我们所知道的一些毒性最强的物质是由传染性细菌产生的破膜蛋白。

For example, a nutritional epidemiologist studying malnutrition may find that infectious bacteria in contaminated water can change a child's gut bacteria, making them more prone to malnutrition.

例如，研究营养不良的营养流行病学家可能会发现，受污染的水中的传染性细菌会改变儿童的肠道细菌，使他们更容易营养不良。

Pollen from trees and grass, and mold spores from tiny fungi find their way into your mucous membranes and your body attacks these innocuous travelers the same way it would infectious bacteria.

来自树上和草地上的花粉，和来自真菌的霉菌孢子都能够进入你的黏膜而你的身体就会像对待感染性细菌一样攻击这些无辜的来访者。