https://www.ffhdj.com/index.php/ffhd/article/view/268
Decaffeinated coffee induces expression of tight junction proteins in rats with NAFLD (non-alcoholic fatty liver disease.)
Conclusions: HFD (high fat diet) impairs the intestinal tight junction barrier integrity. Coffee increases the expression of tight junctions proteins reverting the altered gut permeability, and reduces TLR4 expression.
So, high fat diets make your gut more permeable, but decaffeinated coffee can reverse some of that damage, by rebuilding the tight junctions. Therefore, decaf coffee is pretty good for you! Just don’t load it down with sugar and cream.