Perhaps you should try some spelling variations:
plant microbiomes » plant microbiome, plant microbes, plant microbe
plant microbiota » plant microbiome, plant microbial, tract microbiota
what microbiota » bat microbiota, tract microbiota, wheat microbiome

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: immunosuppression ((what microbiota) OR (((plant microbiota) OR (plant microbiomes)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "immunosuppression ((what microbiota) or (((plant microbiota) OR (plant microbiomes))))".
• Adding a wildcard symbol may retrieve word variants: immunosuppression ((what microbiota) or (((plant microbiota) OR (plant microbiomes))))*.