Join the open source uBiome GitHub repository for microbiome data and tools
ubiomeblog.com
ubiomeblog.com
The resolution from uBiome data is also 16s, and (likely) too low to yield good information.
There is no definition of a good microbiome. The research is still in its infancy. Attempting to 'improve' your microbiome would likely be a mistake. The upside is that you may have contributed by paying uBiome.
https://help.github.com/articles/conditions-for-large-files/