Can a saliva test predict the best way to treat obesity?
May 23, 2023 – Sounds like a simple solution to a complicated problem: Find out what nice about obesity based on a one-time genetic saliva test. Then you and your doctor can get a better idea of whether obesity medications or other treatments are more likely to work for you.
The goal of creating obesity types and tests is to increase your chances of losing weight and improving your health and well-being, as opposed to a one-size-fits-all approach. This is what Mayo Clinic researchers had in mind when they created the four phenotypes of obesity.
Obesity experts unaffiliated with the research have concerns and say independent studies are needed to prove the strategy’s potential.
This research could help predict who will respond best to popular anti-obesity drugs, said Andres Acosta, MD, PhD, co-founder of Phenomix Sciences, the company behind the tests. These drugs include drugs called glucagon-like peptide receptor agonists (GLP-1s), such as liraglutide (Saxenda, Victoza) and semaglutide (Ozempic, Wegovy).
“We know that not everyone responds to GLP-1. In fact, about one-third of patients do not do well with GLP-1s,” said Acosta, MD, assistant professor of medicine and investigator in the Division of Gastroenterology and Hepatology at the Mayo Clinic in Rochester.
Longest in development is the “My Phenome Hungry Gut” test for predicting GLP-1 response. People in the hunger group tend to empty their stomachs more quickly after eating and are more likely to feel hungry after a while, as shown by the company’s website.
A pilot study to test how well it works began in April in three primary care practices. Plans are to expand real-world testing to this and other obesity types later this year.
The other obesity categories:
- “Hungry brain”, where the brain does not recognize the signs of stomach fullness
- “Emotional hunger”, where the desire to eat is driven by emotions, anxiety and negative feelings
- “Slow burn” where people have a slow metabolism and low energy levels
People in these categories may be more likely to benefit from other obesity management strategies, such as changing their diet or intragastric balloon.
A few things to consider
While they applaud their efforts to more accurately treat obese people, not all experts are convinced that this saliva test will be the answer. The company’s research may seem promising, but checking the results is warranted.
“Can we get better results with things like this? Well, that’s the hope,” said Jaime Almandoz, MD, medical director of Weight Wellness at the University of Texas Southwestern Medical Center in Dallas.
“We still don’t have randomized trials looking at obesity phenotyping,” said Almandoz, who is also a spokesperson for The Obesity Society, a professional group of clinicians, researchers, educators and others dedicated to the science of obesity. treatment, prevention.
There’s always concern when a diagnostic test is developed for commercial use, said Daniel Bessesen, MD, professor of medical endocrinology, metabolism and diabetes at the University of Colorado School of Medicine in Denver. “What they are talking about is extremely important. But it’s a company. I think it’s a company that sells a product.”
In an online search, Bessesen couldn’t find any outside studies showing how well the saliva test works. Referring to the work of De Acosta and Michael Camilleri, MD, another co-founder of Phenomix, he said, “I found that they did some papers that I hadn’t read before, and they were good.”
“These guys are smart guys. And they worked a lot on it [the movement of food through the gut] and how it relates to obesity and response to certain therapies,” said Bessesen, who is also a spokesperson for The Obesity Society. “So their scientific work is aligned with this field.”
Validation of any research is important because the obesity industry is known for many quick weight loss strategies with little or no science behind them, he said.
It’s also essential, he said, because “anytime you’re doing something commercial in obesity, you have to recognize that obese people are a vulnerable population. These people constantly face stigma and prejudice.”
Removing the stigma
If knowing the type of obesity makes a difference, it could change the conversation between people and their medical providers, Acosta said. It can also help remove some of the stigma surrounding obesity.
“We’re changing the conversation because now we can say, ‘Hey, you’re obese because you have the Hungry Gut phenotype.’ And because of that, you’re going to respond to this drug,” Acosta said. Phenotyping suggests a strong genetic predisposition—the biological basis of obesity.
“So it’s not just a way to deflect responsibility, it’s a way to explain that there’s a reason for obesity,” Acosta said. It tells people, “You are not a failure.”
A more cost-effective treatment?
According to Almandoz, targeting obesity treatment can also save overall healthcare costs. He estimated the cost at $1,400 a month for “semaglutide forever and ever,” or at least $1,400 a month for a 3-month trial to see if the drug works in a specific obese person.
“That’s a lot of money when you extrapolate that to people who are likely to qualify for treatment,” he said. A total of 42% of Americans meet the CDC definition of obesity.
“You can imagine the cost of providing obesity therapy to everyone and using the most effective class of drugs, which is over a thousand dollars a month indefinitely,” Almandoz said. “It’s not like we shouldn’t treat everyone. That’s not the message I’m saying. But if we’re looking at yield or value for obesity management in a resource-constrained setting, it might be best to start with who is most likely to benefit.”
How four types of obesity were created
Starting in 2015, Acosta and his colleagues began comparing tests in normal-weight and obese people. With the help of artificial intelligence and machine learning, obesity was initially classified into 11 types. They realized that many types of obesity were impractical for doctors and obese people, so they combined them into four phenotypes.
“Artificial intelligence was followed by machine learning, as I like to call it, HI, or human intelligence,” he said.
The saliva test checks about 6,000 relevant genetic SNPs. SNPs are “single nucleotide polymorphisms”, or changes in genes. Six thousand genetic changes may seem like a large number to check until you learn that humans have 5-6 million SNPs in their DNA.
The results are translated into a score that represents a low or high risk for the hungry gut or other types of obesity. “You can have all six thousand genetic mutations or zero,” Acosta said.
To move forward
After soft launching the Hungry Gut test in April, Phenomix plans to continue studying the saliva test in other types of obesity.
Acosta is not aware of any direct competition for Phenomix, although that may change. “I think we’re the only diagnostic company in the field right now. But if it really is a $14.8 billion market, we’re going to see a lot of diagnostic companies try to do what we’re doing — if we’re successful,” he said.
An October 2022 report Polaris Market Research estimates that the global market for obesity treatment—drugs, surgery, and all—was about $14 billion in 2021. The same report predicts that the market will grow to $32 billion by 2030.
Source: https://www.webmd.com/obesity/news/20230525/can-a-saliva-test-predict-the-best-way-to-manage-obesity?src=RSS_PUBLIC
