Image credit: David Todd McCarty (CC0)
Tens of trillions of microbes living in the gut help humans and other animals digest their food. In the process, the microbes provide necessary nutrients for themselves and the animal. Learning more about the interaction of food components and gut bacteria could help scientists to better understand how different diets affect human health. Currently, studying these complex interactions is challenging, but new technologies that measure microbial nutrient processing in the gut could help.
Now, Wesener et al. show that swallowable microscopic biosensors can measure how gut bacteria break down nutrients from food. To make the biosensors, Wesener et al. attached complex carbohydrates extracted from peas and fluorescent tags to microscopic beads. In the experiments, mice colonized with human gut microbes were fed the beads along with a traditional low fiber, Western diet. Some of the animals also received fiber supplements.
The microscopic beads were then recovered from the intestines after digestion and the remaining carbohydrates on the beads were measured. The genetic makeup of the gut microbiome and the expression of microbial genes was also examined. The experiments revealed which pea carbohydrates the gut microbes consumed and showed that pairing certain carbohydrates together on the microbead surface increased their digestion in mice that received fiber supplements.
If future studies prove that the microbead biosensors created by Wesener et al. are safe for humans to ingest, they could be used to help diagnose how well a person’s gut microbiota can process different foods. Studies using the microbead sensors may also help scientists develop more nutritious foods or supplements that promote the growth of microbes important for health.
