Who was the scientist that first linked illness to microbes?

Louis Pasteur is recognized for being the scientist who first linked illness to microbes through his groundbreaking work on germ theory. In the late 19th century, Pasteur conducted experiments that demonstrated the role of microorganisms in causing diseases. He disproved the theory of spontaneous generation, showing that microorganisms were responsible for fermentation and putrefaction, which paved the way for understanding how pathogens could cause illness.

Pasteur's work laid essential foundations for both microbiology and immunology. His development of the vaccination process, especially against rabies and anthrax, further underscored the importance of microbes in health and disease. This significant contribution helped shift medical thinking toward recognizing microbes as the primary agents of infectious diseases, ultimately leading to advancements in hygiene, sterilization, and preventive medicine.

Other scientists, such as Robert Koch, built upon Pasteur's theories and established principles for identifying specific pathogens, but it was Pasteur who made the initial critical connection between microbes and disease.