Bill Nye the Science Guy (1993)

S3E9 Germs

Stay calm, but remember that microbes are everywhere you look. These tiny single-celled entities include bacteria, viruses, protozoa, and fungi. Fortunately, your skin acts as a barrier, preventing many of these organisms from entering your body. If some manage to get through, your immune system is equipped with robust defenses to combat and eliminate them. It's also worth noting that not all microbes are harmful; many beneficial ones, like those residing in our gut, play a crucial role in our digestive health.