Transformation pathways and metabolic activity of free chlorophyll compounds from chloroplast thylakoid membrane under in vitro gastrointestinal digestion and colonic fermentation in early life

Abstract

Abstract Thylakoid membrane was subjected for the first time to an in vitro gastrointestinal digestion and colonic fermentation process in early life to investigate transformation pathways and metabolic activity of free chlorophyll compounds. Volume-mean diameters proved that the thylakoid membrane was digested, releasing free chlorophylls. The released chlorophylls favored the pheophytinisation reaction under in vitro gastrointestinal digestion, leading to the formation of pheophytin a and pheophytin b. Gut microbiota in early life of Blautia, Bacteroides and Enterococcus utilized a wide range of pheophytin-types derivatives, which stimulated the production of pheophorbide a, pheophorbide b, 151-hydroxy-lactone pheophorbide a and 132-hydroxy pheophorbide a. Accordingly, a high increase in the concentration of acetic acid, propionic acid, butyric acid and valeric acid was observed due to fermentation of pheophytins by the intestinal microbiota. We believe that this systematic investigation will be extended to in vivo to better understand health benefits of chlorophylls.