• Posted May 21, 2024

'Hungry Gut' Gene Test Shows Who'll Benefit Most From Wegovy

You've watched others shed pounds in a matter of weeks after taking one of the new blockbuster weight-loss drugs, so you decide to try one of the medications yourself, only to discover the needle on your bathroom scale barely budges.

Why? New research presented Monday at the Digestive Disease Week conference in Washington, D.C., suggests genes might be at play.

Some patients will lose 20% or more of their body weight, but one study found that roughly 1 in 7 people who used the GLP-1 agonist semaglutide for more than a year didn't lose at least 5% of their starting weight.

Now, research shows that a new test that assigns a genetic risk score to patients may be able to spot who is likely to be successful on injected weight-loss medications.

The test, MyPhenome, was developed by researchers at the Mayo Clinic and licensed last year by a company they founded called Phenomix Sciences. It costs $350 and must be ordered by a health care provider, CNN reported.

"Our data support that obesity has a strong genetic and biological basis that varies within patients living with obesity," lead investigator Dr. Maria Daniela Hurtado Andrade said in a company news release. "Furthermore, our results underscore the potential of individualizing therapy to improve outcomes that will ultimately translate into improved health."

"We think that the test will be able to explain who will be able to lose weight, and we can predict with 95% accuracy who will lose more than 5% with this genetic test,"said Dr. Andres Acosta, a gastroenterologist and researcher at the Mayo Clinic who helped develop the test, told CNN. He is also president of Phenomix.

Being able to predict success, or the likelihood of failure, could save time and money: These medications aren't cheap, and they aren't always covered by insurance or may come with a high copay, Acosta noted.

What does the test find?

It looks for 6,000 changes in 22 genes in the signaling pathway for the GLP-1 hormone, and it assigns each person a score that classifies them as either "hungry gut"-positive or "hungry gut"-negative.

People who are hungry gut-positive have normal responses to hormone signaling in the brain, the researchers said. Meanwhile, people who are hungry gut-negative don't respond as well to hormonal signals from the stomach that tell the brain it's time to stop eating. 

Acosta says the test classifies those people as having a hungry brain, and they may need different types of interventions to lose weight, such as weight-loss surgery.

In the recent small study of 84 people enrolled in a weight loss registry at the Mayo Clinic, researchers ran the test on stored blood or saliva samples.

After a year, people who were hungry gut-positive lost an average of 19% of their starting weight while on semaglutide, nearly double the 10% of body weight lost by people who were hungry-gut negative.

Importantly, the new research has not been published in a peer-reviewed medical journal, so the findings are considered preliminary.

"We do need to test these in a randomized, double-blinded, placebo-controlled trial that we have done for other medications. That's the highest gold standard,"Acosta said.

"But at this point, we can say that these outcomes were in patients who were blinded to the results as well as the investigation,"he added, meaning that patients didn't know whether they were hungry gut-positive or hungry gut-negative while they were using the drug.

More information

The Obesity Medicine Association has more on weight-loss drugs.

SOURCE: Phenomix Sciences, news release, May 20, 2024; CNN