What is Germ theory denialism?

Germ theory denialism is the pseudoscientific belief that germs do not cause infectious disease, and that the germ theory of disease is wrong. It usually involves arguing that Louis Pasteur's model of infectious disease was wrong, and that Antoine Béchamp's was right. In fact, its origins are rooted in Béchamp's empirically disproven theory of pleomorphism. Another obsolete variation is known as terrain theory and postulates that the state of the internal environment determines if germs cause disease rather than germs being the sole cause of it. Terrain theory explains why so many people can encounter germs without getting sick, while other people do get sick.