This 2021 review subject was berries and health:
“Phenolic compounds present in different berries (raspberry, blueberry, goji berry, black currant, strawberry, cranberry, and blackberry) were summarized based on up-to-date information and their beneficial health effects. Compounds such as anthocyanins, flavonols, and phenolic acids occur in different concentrations depending on berry type.
Polyphenols are the ‘new’ prebiotics. A more recent definition of prebiotics is ‘a substrate that is selectively utilised by host microorganisms and conferring a health benefit.’
Only 5–10% of total intake is absorbed in the small intestine. Remainders can reach the large intestinal lumen, where they may be subjected to gut microbial community enzymatic activities. Microbiota can catabolize flavonoids that have not been absorbed into smaller molecules, such as phenolic and aromatic acids, which can then be absorbed by intestinal villi.
Increase of beneficial bacteria such as Bacteroidetes, decrease of Firmicutes, and production of short-chain fatty acids is almost consensus among studies. More in vivo data are required to understand mechanisms of action, while clinical trials using different characteristics (i.e., gender, age, existence of diseases) should be performed so new information on bioactivity of berries can be unveiled.”
https://www.sciencedirect.com/science/article/abs/pii/S2214799321001028 “Berry polyphenols and human health: evidence of antioxidant, anti-inflammatory, microbiota modulation, and cell-protecting effects (not freely available) Thanks to Dr. Anderson S. Sant’Ana for providing a copy.
It’s summer, and time to gorge on berries! We’ll deal with overindulgences later.
Surface Your Real Self 
So, it seems like everyone should be eating stuff like berries (blue, black, rasp, straw, etc.), oats, and, of course, broccoli sprouts, daily? Of course, other stuff like green leafy vegetables, cruciferous vegetables, garlic, and spices are probably good to include too. That would appear to help ensure a healthy gut (along with, obviously, cutting out processed foods, sugars, alcohol, etc.).
Hi Carl! Thanks for commenting.
One thing I didn’t mention about this review was that if it was going to redefine polyphenols as the ‘new’ prebiotics, and estimate only 5-10% absorption in the small intestine, they needed to keep going onto the large intestine and disclose prebiotic evidence for estimates there.
The Measuring bioavailability human study found 15% of ingested raspberry anthocyanins were absorbed. Better than 5-10%, but not anywhere near sulforaphane’s 80%.