"The device's design is analogous to a continuous glucose monitor that sits on your arm and measures levels right beneath your skin," said Northwestern's Shana O. Kelley, who led the study.

Mrs Carr-Gomm, from Lewes in East Sussex, had Type 1 diabetes, meaning she had to take insulin every day to keep her blood glucose levels under control.

After introducing the gut microbes into microbe-free mice, the researchers measured changes in mouse physiology over time, including weight gain, fat percentage, fasting glucose, liver function and other traits.

The sensing system accurately determined pH, temperature and dissolved oxygen level in these samples and identified changes in the concentrations of the ions and glucose.

Experimental studies have shown that the use of significantly higher doses of vitamin D than recommended slightly reduces the risk of developing type 2 diabetes in individuals with impaired glucose metabolism, i.e., those with prediabetes.