Google scholar and ckntact relevant folks at NIH https://www.nih.gov/news-events/nih-research-matters/healthy-human-microbiome

NIH Human Microbiome Project - Home (hmpdacc.org)

There was a virtual conference in November 2021 "Reshaping the Microbiome through Nutrition". I believe there have been presentations with the control cohorts. Check the agenda and talks if interested. The link to the conference: https://conferences.nature.com/event/83bbeaa0-9f04-42f4-a69c-beb294c7a3b6/summary

thank you all for your suggestions! I did explore the Human Microbiome Project and their data portal but it was too much for me. I don't have the skills yet to utilise the raw data. However, I discovered many other projects along the way.

GutFeelingKB—A reference list for healthy human gut organisms. GutFeelingKB is a compilation of highly curated data and metadata associated with organisms identified as present in the samples they analyzed. GutFeelingKB consists of 157 organisms which fall into sixty distinct genera, as seen in S2 Table which is arranged by species. Published article: Article Baseline human gut microbiota profile in healthy people and ...

The full table can be down-loaded at https://hive.biochemistry.gwu.edu/gfkb.

I had been using the online app Calypso, but that is down at the moment. I found another free online tool: Microbiome Analyst from Xia Lab https://www.microbiomeanalyst.ca/

Here you can do stats and charts but also compare with published data in various populations. You can upload your OTU table and compare with published data.

I am still struggling with my OTU table because it has been formatted in the Calypso format which is not compliant with the standard way eg Greengenes taxonomy. My table has taxonomy headers but each row does not included the full taxons so I can't compare it to anything else until I manage to reformat it.