Earlier quoted context omitted.
IIRC inflammation is linked to endotoxins produced by bacteria in the gut. Apparently curcumin has a good reputation for helping people with inflammatory conditions like that. And it's been proposed that it yields positive benefits by modulating the gut rather than being bioactive (curcumin is famously not bioactive).
You’re being downvoted because it sounds like woo but the people downvoting aren’t up to speed on the latest science. Nightshades are tolerated by people with healthy guts and there is a smaller set of people with a gut dysfunction that means the solanine (alkaloids) in nightshades causes leaky gut syndrome leading to the inflammation you are talking about. Curcumin (turmeric) does alleviate this inflammation pretty…
We absolutely know for a fact that some people can have dysfunction of the tight junctions which make up the lining of the intestines. We don't know too much about it, but the idea that bacteria and endotoxins can pass through the gut wall and into the bloodstream is established fact at this point. "Endotoxin" has the sound of a pseudoscientific word, but it simply refers to the lipopolysaccharides that bacteria use to build their outer membranes.
People with some autoimmune diseases have been found to have circulating endotoxins and other bacterial byproducts in their peripheral blood, though the process (bacterial translocation) and the mechanism by which these affect the body are both poorly understood. There's been very little research into what processes can cause intestinal permeability and gut dysbiosis in autoimmune patients. For example, it's unclear if it's the cause of the autoimmunity (permeability leading to SIBO-like bacterial overload leading to an aberrant immune response), or if the autoimmune disease causes it (systemic inflammation leading to permeability).
I've not seen any peer reviewed evidence about nightshades or glycoalkaloids. There's some research on curcumin and quercetin that's interesting.