Isomaltooligosaccharides Sustain the Growth of Both and in Animal Models.

The human digestive tract is colonized by trillions of bacterial cells that play important roles in human health and diseases. It is well known that dietary habits are associated with human microbiota enterotypes. However, the factors that determine the enterotype still remain elusive. In this study, it was first examined, via batch fermentation, how different carbohydrates affect the and enterotypes. Among the 11 substrates (fructo-, galacto-, xylo-, manno-, and isomalto-oligosaccharides [IMO] and lactulose, raffinose, starch, inulin [INU], mannitol, and xylitol) tested, IMO, INU, and starch were found to sustain the growth of through batch fermentation. The development of the and enterotypes was further simulated in chemostats using fecal samples. IMO coupled with faster dilution rates and lower pH were required to sustain the growth of Prevotella copri in the chemostat based on 16S rRNA gene and metagenomic sequencing. Meanwhile, starch with relatively lower dilution rates and higher pH was required to support the development of the enterotype. Amylo-α-1,6-glucosidase, pectin, and xylan lyases were the carbohydrate-active enzymes associated with the enterotype. The enterotype was associated with more diversified carbohydrate-active enzymes. Consistently, since honey contains high isomaltose content, mice fed IMO and honey displayed an increased relative abundance of in the colon. In conclusion, both systems and a mouse model were used to demonstrate that IMO maintains the enterotype. This result provides insight into the nutritional requirements underlying gut enterotype formation. The enterotype type is a human traditional enterotype with high dietary fiber intake, which is related to healthy ageing and Parkinson's disease development. Manipulations of the dwelled gut microbes by dietary isomalto-oligosaccharides efficiently sustained type enterotypes, indicating that it can be used in the improvement of elderly health by increasing the gut transit time.