Microbiome, Probiotics & Gut Nutrition

Biography

Biography: Pamela Genereux

Abstract

Porphyra sp. (Nori) is a red macroalga mainly composed of porhyran, a bioactive sulfated polysaccharide. Studies on monoand oligosaccharides derived from porphyran hydrolysis have demonstrated that their beneficial properties could be improved. However, the antimicrobial properties and their effects on gastrointestinal health as a prebiotic remains poorly documented. This study focuses on the production of porphyran hydrolysates extracted in Atlantic Nori (Océan de Saveurs) with potential biological activities for health (antimicrobial and prebiotic effects) thanks to two specific enzymes discovered by Roscoff Biological Station (RBS). Porphyran hydrolysis were performed with β-agarase and β-porphyranase. To characterize the hydrolysates, the determination of reducing and total sugars as well as high-performance liquid chromatography (HPLC) were carried out. The antimicrobial capacity against various microbes was tested by well diffusion. The prebiotic potential was evaluated by micro fermentations of the different hydrolysates at different doses and with the multicompartment dynamic simulator of the human intestinal microbial ecosystem (SHIME). The porphyran hydrolysis using β-agarase generated oligosaccharides of smaller sizes compared to the one using β-porphyranase. Additionally, no antimicrobial effect was obtained with the hydrolysates. As a prebiotic, no significative results were noted for the hydrolysates using the micro fermentations. On the other hand, in SHIME, short-chain fatty acids (SCFA) analysis showed that the hydrolysates obtained with β-porphyranase caused an increase in the propionate ratio and a modulation of the butyric ratio in the two intestinal regions tested for the two donors. Finally, these observations suggest that a porphyran hydrolysate could modulate the intestinal microbiota by increasing the production of propionate, a metabolite associated with the reduction of obesity