Fermentation of alginate and its derivatives by different enterotypes of human gut microbiota: Towards personalized nutrition using enterotype-specific dietary fibers.

Alginate and its derivatives are widely used as food additives and dietary fibers. Previous studies indicated that alginate, polyguluronate (PG) and polymannuronate acid (PM) could be fermented by human gut microbiota. However, how different compositions of the microbiota may affect the fermentation outcomes of these polysaccharides remains unknown. Here we show that Bacteroides-dominated microbiota (Bacteroides enterotype) is more proficient at degrading and utilizing PG and PM as compared to Prevotella-dominated (Prevotella enterotype) and Escherichia-dominated microbiota (Escherichia enterotype). Enterotype dictates the fermentation outcomes of the three fibers and the amount of short-chain fatty acids (SCFAs) that are produced. Fermentation of alginate and PM by Bacteroides-dominated microbiota produced the highest amount of total SCFAs and butyrate. Our study demonstrates an enterotype-specific effect of microbiota on the fermentation of alginate and its derivatives and highlights that personalized nutrition using dietary fibers should be tailored according to individual's composition of the gut microbiome.