High Viscosity Slows the Utilization of Rapidly Fermentable Dietary Fiber by Human Gut Microbiota

In the present study, the influence of viscosity on the fermentation characteristics of fructooligosaccharides (FOS) by gut microbiota was examined. Different concentrations of methylcellulose (MC) were added to create varying viscosities and the mixture was fermented with FOS by gut microbiota. The results demonstrated that higher viscosity had a significant impact on slowing down the fermentation rate of FOS. Specifically, the addition of 2.5 wt% MC, which had the highest viscosity, resulted in the lowest and slowest production of gas and short-chain fatty acids (SCFAs), indicating that increased viscosity could hinder the breakdown of FOS by gut microbiota. Additionally, the slower fermentation of FOS did not significantly alter the structure of the gut microbiota community compared to that of FOS alone, suggesting that MC could be used in combination with FOS to achieve similar prebiotic effects and promote gut health while exhibiting a slower fermentation rate.