Microgels from food waste as a tool to understand microbe interactions with hierarchical fiber networks

The gut microbiome can drastically influence mortality and disease progression for end stage kidney disease patients. This is largely due to their production of toxic metabolites known as uremic toxins that originate in the intestinal tract and are absorbed into the blood stream. Recent studies demonstrated that switching patients to a high fiber diet composed of structurally complex foods can completely alter the gut microbiome by promoting beneficial communities and binding and removing toxins. However, this proactive action is not well understood. Our work focuses on demystifying the structure-function relationships of indigestible fibrous biomaterials and the effects of structural hierarchy on toxin binding and microbial interactions. We have developed microgel sorbents from cellulose extracted from food waste with the goal of binding and removing uremic toxins from simulated intestinal conditions. We can tune the hierarchical structure of the cellulose using small molecule additives that control gelation during microgel formation. The resistance of the microgels to digestion were investigated by exposing them to an in vitro digestive system and simultaneously tracking changes in structure and mechanics with time. Finally, the microgels are introduced to microbial communities to understand how structure and mechanics influence microbial interactions and toxin absorption.