Researchers find metformin turns gut cells into glucose absorbers

Researchers have uncovered how metformin, one of the most commonly prescribed medications for type 2 diabetes in the U.S., works within the body. A recent study reveals that metformin transforms gut cells into a "sugar sink," significantly lowering glucose levels. This discovery sheds light on a mechanism that has puzzled scientists for decades.

The interest in metformin's function has grown since its FDA approval in 1995, even though evidence of its effects on glucose absorption dates back to 1989. Initially, research focused on the drug's ability to reduce glucose production in the liver. However, recent imaging studies showed that metformin causes the gut to absorb more sugar, prompting researchers to reconsider earlier findings. Notably, University of Cambridge researcher Stephen O’Rahilly noted that previous studies seemed to have been overlooked as new theories emerged.

In their recent study, a team led by Northwestern University biologist Navdeep Chandel investigated how metformin affects both glucose absorption in the gut and mitochondrial oxygen use. They conducted experiments with mice that involved replacing a crucial enzyme in the mitochondria with a yeast enzyme unaffected by metformin. The results confirmed that while respiration proceeded normally, metformin did not reduce blood sugar levels. This indicates that high levels of metformin prompt gut cells to switch their energy production method, utilizing more sugar.

This breakthrough could have significant implications for understanding metformin's broader effects, including its potential connections to anti-aging. As researchers continue to explore the drug's mechanisms, they may uncover new avenues for diabetes treatment and metabolic health. Understanding how metformin operates could lead to improved therapies and enhance its role in managing blood sugar levels effectively.