Bioaccessibility, antioxidant activity and modulation effect on gut microbiota of bioactive compounds from <i>Moringa oleifera</i> Lam. leaves during digestion and fermentation <i>in vitro</i>

Researchers examined how bioactive compounds from moringa leaves behave during human digestion and their effects on gut bacteria using laboratory simulation models. The study tracked the release of phenolic compounds (plant antioxidants) and flavonoids as moringa leaves passed through simulated oral, gastric, and small intestine digestion, then observed their impact during colonic fermentation. During digestion, 24.95 mg of phenolic compounds and 21.66 mg of flavonoids were released per gram of dried moringa material. Different beneficial compounds emerged at each digestive stage: 6,8-di-C-glucosylapigenin during oral digestion, catechin in the stomach, and quercetin-3-O-β-d-glucoside plus ferulic acid in the small intestine. The antioxidant activity remained strong throughout digestion, correlating with the release of these compounds. When the digested moringa reached the simulated colon environment, it promoted the growth of beneficial bacteria and increased production of short-chain fatty acids including acetic, propionic, and butyric acids. These fatty acids are important for colon health and caused the pH to decrease, creating conditions that favor beneficial microbes. The findings demonstrate that moringa leaves maintain their bioactive properties through the digestive process and can positively influence gut microbiota composition, supporting their potential as a functional food ingredient.