Precision approaches to microbiota modulation: Using specific fiber structures to direct the gut microbial ecosystem for better health

By now, hundreds of scientific articles show the differences in gut microbiota composition and function between states of health and disease, leading to the idea that gut microbiota modulation is a promising way to achieve better health. But in practice, changing the complex community of microbes in the gut has proved challenging—the gut microbiota of the average adult is remarkably stable.

When it comes to diet, non-digestible carbohydrates are the main way to provide nutritional support to microbial populations and to modulate these communities, either in composition or in function. Can these dietary fibers be used to modulate the gut microbiota in a precise manner, with the aim of inducing certain health effects?

Prof. Jens Walter of APC Microbiome Ireland addressed this topic in a plenary lecture at the ISAPP 2020 annual meeting, titled: Precision microbiome modulation through discrete chemical carbohydrate structures.

Walter sees the gut microbiota as an complex ecological community of interacting microbes that is remarkably stable in healthy adults (albeit with a high degree of inter-individual variation). In order to precisely modulate gut microbiomes through diet, scientists must consider the ecological principles that shape these communities and determine how they function.

In the lecture, Walter introduced a perspective for using discrete fiber substrates to precisely modulate gut microbiota – a framework first articulated in a 2014 paper by Hamaker and Tuncil. According to this framework, gut microbiomes can be precisely manipulated, whether to achieve a certain microbiota composition or the production of health-relevant metabolites, through the use of specific fiber structures that are aligned with microbes that have the ability to utilize them. Walter explains some of the main challenges of the framework, which relate to the vast inter-individual differences in the gut microbes that are present, and their response to fiber; and discovering the exact dose of a fiber required for reliable changes in a person’s gut microbiota.

At the core of the presentation is a study by the Walter Lab that systematically tested the framework through a human dose-response trial using resistant starches with slight differences in their chemical structure. The findings of the study, which were published this year, illustrate how this ecological concept can be successfully applied. This shows the colonic microbiota can be successfully shaped in a desired manner with discrete dietary fiber structures.

See Prof. Walter’s presentation in full here.