Side-effects range from mild to very serious depending on the antibiotics used, the microbial organisms targeted, and the individual patient.

Some animals also have digestive adaptations to improve their ability to digest woody plants either with or without the aid of microbial organisms.

All plants and animals, from protists to humans, live in close association with microbial organisms, cf. the human microbiome.

Bacteriophages, and microbial organisms, can be frozen in stasis, facilitating comparison of evolved strains to ancestors.

Back-contamination is the informal but widely employed name for the hypothetical introduction of microbial extraterrestrial organisms into Earth's biosphere.

Back-contamination - The theoretical contamination of Earth's biosphere from microbial extraterrestrial organisms.

A paradoxical observation has been the strong association of certain microbial organisms with autoimmune diseases.

The chemicals may be nutrients, neutral or biocides for the microbial organisms.

(b) inhibit vital processes of endo- or ectoparasites and microbial organisms.

Most plants have endophytes, microbial organisms that live within them.