"Journey to the Microcosmos: Are Microbes Good or Bad for Humans?" explores microbiology through the history of germ theory, microscopy, and the complex roles microbes play in human health and ecosystems. The video explains pathogens, parasites, bacteria, nematodes, microbiomes, probiotics, and antibiotic resistance, showing that while some microorganisms cause disease, most are harmless or beneficial. It highlights examples such as swimmer’s itch, nutrient cycling in soil, bacterial uses in food production, and Euglena toxins studied for cancer research. With clear scientific vocabulary and real-world context, this documentary supports life science curricula in biology, ecology, public health, and scientific inquiry by examining how microbes influence bodies, environments, and modern medicine. Part of the "Journey to the Microcosmos" series.