May 23, 2023 – It seems like a straightforward solution to an advanced problem: Find out what Type A one-time genetic saliva test will determine your risk of obesity, which can enable you and your doctor determine whether obesity medications or other treatments usually tend to give you the results you want.
The goal of developing obesity types and tests is to extend your likelihood of shedding weight and improving your health and well-being, somewhat than taking a one-size-fits-all approach. That's exactly what Mayo Clinic researchers had in mind once they developed 4 obesity phenotypes.
Obesity experts not involved within the research have some concerns and say independent studies are needed to substantiate the potential of this strategy.
This research could help predict who will respond best to common obesity drugs, said Andres Acosta, MD, PhD, co-founder of Phenomix Sciences, the corporate behind the tests. These drugs include a category of medication called glucagon-like peptide receptor (GLP-1) agonists, corresponding to liraglutide (Saxenda, Victoza) and semaglutide (Ozempic, Wegovy).
“We know that not everyone responds to GLP-1. In fact, about a third of patients do not tolerate GLP-1 well,” said Acosta, an assistant professor of medication and researcher within the division of gastroenterology and hepatology on the Mayo Clinic in Rochester, Minnesota.
The most advanced test in development is the My Phenome Hungry Gut test for predicting the GLP-1 response. People on this hungry gut group are likely to empty their stomachs more quickly after a meal and usually tend to feel hungry again shortly afterwards, as shown in the company website.
A pilot study to check the effectiveness of this system began in April in three GP practices, and real-world testing shall be expanded to incorporate these and other varieties of obesity later this yr.
The other obesity categories are:
- “Hungry brain,” where the brain doesn’t recognize signals that the stomach is full
- “Emotional hunger,” where the need to eat is triggered by emotions, fears, and negative feelings
- “Slow burn” when those affected have a slow metabolism and low energy levels
People in these categories could also be more more likely to profit from other strategies to combat obesity, corresponding to changing their weight-reduction plan or using a intragastric balloon.
Some things to think about
While the corporate's efforts to supply more precise treatment for obesity patients are welcomed, not all experts are convinced that this saliva test is the answer. The company's research could seem promising, but verification of the outcomes is required.
“Can we get better results with things like this? Well, that's the hope,” said Dr. Jaime Almandoz, medical director of Weight Wellness on the University of Texas Southwestern Medical Center in Dallas.
“We still don't have randomized trials looking at obesity phenotyping,” said Almandoz, who can also be a spokesperson for the Obesity Society, an expert association of clinicians, researchers, educators and others focused on the science, treatment and prevention of obesity.
There are all the time concerns when a diagnostic test is developed for industrial use, says Dr. Daniel Bessesen, professor of medicine-endocrinology, metabolism and diabetes on the University of Colorado School of Medicine in Denver. “What they're saying is super important. But this is a company. I think this is a company selling a product.”
In a web based search, Bessesen found no outside studies showing how well the saliva test worked. But citing the work of Acosta and Dr. Michael Camilleri, Phenomix's other co-founder, he said, “I found some work by them that I hadn't read before that is good.”
“These guys are smart guys. And they have a lot of work in [the movement of food through the gut] and how that correlates with obesity and response to some therapies,” said Bessesen, who is also a spokesperson for the Obesity Society. “So their scientific work actually fits into that area.”
Validating any research is important because the obesity industry is known for many quick weight-loss strategies, some of which have little or no scientific basis, he said.
This is also important because “any commercial action in the area of obesity must take into account that obese people are a vulnerable population group. These people are constantly confronted with stigma and prejudice.”
Eliminate the stigma
If knowing the type of obesity makes a difference, it could change conversations with doctors, Acosta says. It could also help reduce the stigma around obesity.
“We're going to change the conversation because now we can say, 'Hey, you're obese because you have the hungry gut phenotype. And that's why you're going to respond to this drug,'” Acosta said. Phenotyping suggests a strong genetic predisposition – a biological basis for obesity.
“So it's not only a way to deflect blame, but also to explain that there's a reason for the obesity,” Acosta said. It tells people, “You're not a failure.”
Cheaper treatment?
Targeting obesity could also reduce overall health care costs, Almandoz said. He estimated costs at $1,400 a month “for semaglutide forever and ever,” or at least $1,400 a month for a three-month trial to see if this drug works for a specific person with obesity.
“That's a lot of money when you extrapolate that to the number of people who probably meet the criteria for treatment,” he said. Overall, 42% of Americans meet the CDC definition of obesity.
“You can imagine the potential cost if we were to offer obesity treatment to everyone using the most effective drugs. That would be over a thousand dollars a month, indefinitely,” Almandoz said. “That's not to say we shouldn't treat everyone. That's not the message I'm trying to convey. But when we consider the benefit or utility of treating obesity in a resource-limited setting, it may be best to start with those who are most likely to benefit.”
How they created four obesity types
Starting in 2015, Acosta and his colleagues began comparing tests in normal-weight people with obesity. They used artificial intelligence and machine learning to initially classify obesity into 11 types. They realized that so many obesity types were not practical for doctors and obesity patients, so they grouped them into four phenotypes.
“The machine learning of AI was followed by what I like to call 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 sound like a big number to check until you learn that there are people walking around with 5 to 6 million SNPs in their DNA.
The results are translated into a score that indicates a low or high risk of hungry gut or other types of obesity. “You can have all six thousand genetic mutations, or you may have zero,” Acosta said.
Moving forward
Following the soft launch of the Hungry Gut test in April, Phenomix plans to continue testing its saliva test on other types of obesity.
Acosta is not aware of any direct competitors to Phenomix, but that could change. “I believe we're the one diagnostics company on this space straight away. But if it truly is a $14.8 billion market, we're going to see plenty of diagnostics corporations attempting to do what we're doing — if we're successful,” he said.
A Report from October 2022 of Polaris Market Research estimates that the worldwide marketplace for obesity treatment — drugs, surgery, and the whole lot else — was about $14 billion in 2021. The same report predicts the market will grow to $32 billion by 2030.