This breath test can detect liver disease earlier
Every year, around two million people worldwide die of liver disease. While some people inherit the disease, it’s most commonly caused by hepatitis, obesity and alcoholism. These underlying conditions kill liver cells, causing scar tissue to form until eventually the liver cannot function properly. Since 1979, deaths due to liver disease have increased by 400 percent.
The sooner the disease is detected, the more effective treatment can be. But once symptoms appear, the liver is already damaged. Around 50 percent of cases are diagnosed only after the disease has reached the final stages, when treatment is largely ineffective.
To address this problem, Owlstone Medical, a biotech company in England, has developed a breath test that can detect liver disease earlier than conventional approaches. Human breath contains volatile organic compounds (VOCs) that change in the first stages of liver disease. Owlstone’s breath test can reliably collect, store and detect VOCs, while picking out the specific compounds that reveal liver disease.
“There’s a need to screen more broadly for people with early-stage liver disease,” says Owlstone’s CEO Billy Boyle. “Equally important is having a test that's non-invasive, cost effective and can be deployed in a primary care setting.”
The standard tool for detection is a biopsy. It is invasive and expensive, making it impractical to use for people who aren't yet symptomatic. Meanwhile, blood tests are less invasive, but they can be inaccurate and can’t discriminate between different stages of the disease.
In the past, breath tests have not been widely used because of the difficulties of reliably collecting and storing breath. But Owlstone’s technology could help change that.
The team is testing patients in the early stages of advanced liver disease, or cirrhosis, to identify and detect these biomarkers. In an initial study, Owlstone’s breathalyzer was able to pick out patients who had early cirrhosis with 83 percent sensitivity.
Boyle’s work is personally motivated. His wife died of colorectal cancer after she was diagnosed with a progressed form of the disease. “That was a big impetus for me to see if this technology could work in early detection,” he says. “As a company, Owlstone is interested in early detection across a range of diseases because we think that's a way to save lives and a way to save costs.”
How it works
In the past, breath tests have not been widely used because of the difficulties of reliably collecting and storing breath. But Owlstone’s technology could help change that.
Study participants breathe into a mouthpiece attached to a breath sampler developed by Owlstone. It has cartridges are designed and optimized to collect gases. The sampler specifically targets VOCs, extracting them from atmospheric gases in breath, to ensure that even low levels of these compounds are captured.
The sampler can store compounds stably before they are assessed through a method called mass spectrometry, in which compounds are converted into charged atoms, before electromagnetic fields filter and identify even the tiniest amounts of charged atoms according to their weight and charge.
The top four compounds in our breath
In an initial study, Owlstone captured VOCs in breath to see which ones could help them tell the difference between people with and without liver disease. They tested the breath of 46 patients with liver disease - most of them in the earlier stages of cirrhosis - and 42 healthy people. Using this data, they were able to create a diagnostic model. Individually, compounds like 2-Pentanone and limonene performed well as markers for liver disease. Owlstone achieved even better performance by examining the levels of the top four compounds together, distinguishing between liver disease cases and controls with 95 percent accuracy.
“It was a good proof of principle since it looks like there are breath biomarkers that can discriminate between diseases,” Boyle says. “That was a bit of a stepping stone for us to say, taking those identified, let’s try and dose with specific concentrations of probes. It's part of building the evidence and steering the clinical trials to get to liver disease sensitivity.”
Sabine Szunerits, a professor of chemistry in Institute of Electronics at the University of Lille, sees the potential of Owlstone’s technology.
“Breath analysis is showing real promise as a clinical diagnostic tool,” says Szunerits, who has no ties with the company. “Owlstone Medical’s technology is extremely effective in collecting small volatile organic biomarkers in the breath. In combination with pattern recognition it can give an answer on liver disease severity. I see it as a very promising way to give patients novel chances to be cured.”
Improving the breath sampling process
Challenges remain. With more than one thousand VOCs found in the breath, it can be difficult to identify markers for liver disease that are consistent across many patients.
Julian Gardner is a professor of electrical engineering at Warwick University who researches electronic sensing devices. “Everyone’s breath has different levels of VOCs and different ones according to gender, diet, age etc,” Gardner says. “It is indeed very challenging to selectively detect the biomarkers in the breath for liver disease.”
So Owlstone is putting chemicals in the body that they know interact differently with patients with liver disease, and then using the breath sampler to measure these specific VOCs. The chemicals they administer are called Exogenous Volatile Organic Compound) probes, or EVOCs.
Most recently, they used limonene as an EVOC probe, testing 29 patients with early cirrhosis and 29 controls. They gave the limonene to subjects at specific doses to measure how its concentrations change in breath. The aim was to try and see what was happening in their livers.
“They are proposing to use drugs to enhance the signal as they are concerned about the sensitivity and selectivity of their method,” Gardner says. “The approach of EVOC probes is probably necessary as you can then eliminate the person-to-person variation that will be considerable in the soup of VOCs in our breath.”
Through these probes, Owlstone could identify patients with liver disease with 83 percent sensitivity. By targeting what they knew was a disease mechanism, they were able to amplify the signal. The company is starting a larger clinical trial, and the plan is to eventually use a panel of EVOC probes to make sure they can see diverging VOCs more clearly.
“I think the approach of using probes to amplify the VOC signal will ultimately increase the specificity of any VOC breath tests, and improve their practical usability,” says Roger Yazbek, who leads the South Australian Breath Analysis Research (SABAR) laboratory in Flinders University. “Whilst the findings are interesting, it still is only a small cohort of patients in one location.”
The future of breath diagnosis
Owlstone wants to partner with pharmaceutical companies looking to learn if their drugs have an effect on liver disease. They’ve also developed a microchip, a miniaturized version of mass spectrometry instruments, that can be used with the breathalyzer. It is less sensitive but will enable faster detection.
Boyle says the company's mission is for their tests to save 100,000 lives. "There are lots of risks and lots of challenges. I think there's an opportunity to really establish breath as a new diagnostic class.”
As a child, Wendy Borsari participated in a health study at Boston Children’s Hospital. She was involved because heart disease and sudden cardiac arrest ran in her family as far back as seven generations. When she was 18, however, the study’s doctors told her that she had a perfectly healthy heart and didn’t have to worry.
A couple of years after graduating from college, though, the Boston native began to experience episodes of near fainting. During any sort of strenuous exercise, my blood pressure would drop instead of increasing, she recalls.
She was diagnosed at 24 with hypertrophic cardiomyopathy. Although HCM is a commonly inherited heart disease, Borsari’s case resulted from a rare gene mutation, the MYH7 gene. Her mother had been diagnosed at 27, and Borsari had already lost her grandmother and two maternal uncles to the condition. After her own diagnosis, Borsari spent most of her free time researching the disease and “figuring out how to have this condition and still be the person I wanted to be,” she says.
Then, her son was found to have the genetic mutation at birth and diagnosed with HCM at 15. Her daughter, also diagnosed at birth, later suffered five cardiac arrests.
That changed Borsari’s perspective. She decided to become a patient advocate. “I didn’t want to just be a patient with the condition,” she says. “I wanted to be more involved with the science and the biopharmaceutical industry so I could be active in helping to make it better for other patients.”
She consulted on patient advocacy for a pharmaceutical and two foundations before coming to a company called Tenaya in 2021.
“One of our core values as a company is putting patients first,” says Tenaya's CEO, Faraz Ali. “We thought of no better way to put our money where our mouth is than by bringing in somebody who is affected and whose family is affected by a genetic form of cardiomyopathy to have them make sure we’re incorporating the voice of the patient.”
Biomedical corporations and government research agencies are now incorporating patient advocacy more than ever, says Alice Lara, president and CEO of the Sudden Arrhythmia Death Syndromes Foundation in Salt Lake City, Utah. These organizations have seen the effectiveness of including patient voices to communicate and exemplify the benefits that key academic research institutions have shown in their medical studies.
“From our side of the aisle,” Lara says, “what we know as patient advocacy organizations is that educated patients do a lot better. They have a better course in their therapy and their condition, and understanding the genetics is important because all of our conditions are genetic.”
Founded in 2016, Tenaya is advancing gene therapies and small molecule drugs in clinical trials for both prevalent and rare forms of heart disease, says Ali, the CEO.
The firm's first small molecule, now in a Phase 1 clinical trial, is intended to treat heart failure with preserved ejection fraction, where the amount of blood pumped by the heart is reduced due to the heart chambers becoming weak or stiff. The condition accounts for half or more of all heart failure in the U.S., according to Ali, and is growing quickly because it's closely associated with diabetes. It’s also linked with metabolic syndrome, or a cluster of conditions including high blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels.
“We have a novel molecule that is first in class and, to our knowledge, best in class to tackle that, so we’re very excited about the clinical trial,” Ali says.
The first phase of the trial is being performed with healthy participants, rather than people with the disease, to establish safety and tolerability. The researchers can also look for the drug in blood samples, which could tell them whether it's reaching its target. Ali estimates that, if the company can establish safety and that it engages the right parts of the body, it will likely begin dosing patients with the disease in 2024.
Tenaya’s therapy delivers a healthy copy of the gene so that it makes a copy of the protein missing from the patients' hearts because of their mutation. The study will start with adult patients, then pivot potentially to children and even newborns, Ali says, “where there is an even greater unmet need because the disease progresses so fast that they have no options.”
Although this work still has a long way to go, Ali is excited about the potential because the gene therapy achieved positive results in the preclinical mouse trial. This animal trial demonstrated that the treatment reduced enlarged hearts, reversed electrophysiological abnormalities, and improved the functioning of the heart by increasing the ejection fraction after the single-dose of gene therapy. That measurement remained stable to the end of the animals’ lives, roughly 18 months, Ali says.
He’s also energized by the fact that heart disease has “taken a page out of the oncology playbook” by leveraging genetic research to develop more precise and targeted drugs and gene therapies.
“Now we are talking about a potential cure of a disease for which there was no cure and using a very novel concept,” says Melind Desai of the Cleveland Clinic.
Tenaya’s second program focuses on developing a gene therapy to mitigate the leading cause of hypertrophic cardiomyopathy through a specific gene called MYPBC3. The disease affects approximately 600,000 patients in the U.S. This particular genetic form, Ali explains, affects about 115,000 in the U.S. alone, so it is considered a rare disease.
“There are infants who are dying within the first weeks to months of life as a result of this mutation,” he says. “There are also adults who start having symptoms in their 20s, 30s and 40s with early morbidity and mortality.” Tenaya plans to apply before the end of this year to get the FDA’s approval to administer an investigational drug for this disease humans. If approved, the company will begin to dose patients in 2023.
“We now understand the genetics of the heart much better,” he says. “We now understand the leading genetic causes of hypertrophic myopathy, dilated cardiomyopathy and others, so that gives us the ability to take these large populations and stratify them rationally into subpopulations.”
Melind Desai, MD, who directs Cleveland Clinic’s Hypertrophic Cardiomyopathy Center, says that the goal of Tenaya’s second clinical study is to help improve the basic cardiac structure in patients with hypertrophic cardiomyopathy related to the MYPBC3 mutation.
“Now we are talking about a potential cure of a disease for which there was no cure and using a very novel concept,” he says. “So this is an exciting new frontier of therapeutic investigation for MYPBC3 gene-positive patients with a chance for a cure.
Neither of Tenaya’s two therapies address the gene mutation that has affected Borsari and her family. But Ali sees opportunity down the road to develop a gene therapy for her particular gene mutation, since it is the second leading cause of cardiomyopathy. Treating the MYH7 gene is especially challenging because it requires gene editing or silencing, instead of just replacing the gene.
Wendy Borsari was diagnosed at age 24 with a commonly inherited heart disease. She joined Tenaya as a patient advocate in 2021.
Wendy Borsari
“If you add a healthy gene it will produce healthy copies,” Ali explains, “but it won’t stop the bad effects of the mutant protein the gene produces. You can only do that by silencing the gene or editing it out, which is a different, more complicated approach.”
Euan Ashley, professor of medicine and genetics at Stanford University and founding director of its Center for Inherited Cardiovascular Disease, is confident that we will see genetic therapies for heart disease within the next decade.
“We are at this really exciting moment in time where we have diseases that have been under-recognized and undervalued now being attacked by multiple companies with really modern tools,” says Ashley, author of The Genome Odyssey. “Gene therapies are unusual in the sense that they can reverse the cause of the disease, so we have the enticing possibility of actually reversing or maybe even curing these diseases.”
Although no one is doing extensive research into a gene therapy for her particular mutation yet, Borsari remains hopeful, knowing that companies such as Tenaya are moving in that direction.
“I know that’s now on the horizon,” she says. “It’s not just some pipe dream, but will happen hopefully in my lifetime or my kids’ lifetime to help them.”
Last November, when the U.S. Food and Drug Administration disclosed that chicken from a California firm called UPSIDE Foods did not raise safety concerns, it drily upended how humans have obtained animal protein for thousands of generations.
“The FDA is ready to work with additional firms developing cultured animal cell food and production processes to ensure their food is safe and lawful,” the agency said in a statement at the time.
Assuming UPSIDE obtains clearances from the U.S. Department of Agriculture, its chicken – grown entirely in a laboratory without harming a single bird – could be sold in supermarkets in the coming months.
“Ultimately, we want our products to be available everywhere meat is sold, including retail and food service channels,” a company spokesperson said. The upscale French restaurant Atelier Crenn in San Francisco will have UPSIDE chicken on its menu once it is approved, she added.
Known as lab-grown or cultured meat, a product such as UPSIDE’s is created using stem cells and other tissue obtained from a chicken, cow or other livestock. Those cells are then multiplied in a nutrient-dense environment, usually in conjunction with a “scaffold” of plant-based materials or gelatin to give them a familiar form, such as a chicken breast or a ribeye steak. A Dutch company called Mosa Meat claims it can produce 80,000 hamburgers derived from a cluster of tissue the size of a sesame seed.
Critics say the doubts about lab-grown meat and the possibility it could merge “Brave New World” with “The Jungle” and “Soylent Green” have not been appropriately explored.
That’s a far cry from when it took months of work to create the first lab-grown hamburger a decade ago. That minuscule patty – which did not contain any fat and was literally plucked from a Petri dish to go into a frying pan – cost about $325,000 to produce.
Just a decade later, an Israeli company called Future Meat said it can produce lab-grown meat for about $1.70 per pound. It plans to open a production facility in the U.S. sometime in 2023 and distribute its products under the brand name “Believer.”
Costs for production have sunk so low that researchers at Carnegie Mellon University in Pittsburgh expect sometime in early 2024 to produce lab-grown Wagyu steak to showcase the viability of growing high-end cuts of beef cheaply. The Carnegie Mellon team is producing its Wagyu using a consumer 3-D printer bought secondhand on eBay and modified to print the highly marbled flesh using a method developed by the university. The device costs $200 – about the same as a pound of Wagyu in the U.S. The initiative’s modest five-figure budget was successfully crowdfunded last year.
“The big cost is going to be the cells (which are being extracted by a cow somewhere in Pennsylvania), but otherwise printing doesn’t add much to the process,” said Rosalyn Abbott, a Carnegie Mellon assistant professor of bioengineering who is co-leader on the project. “But it adds value, unlike doing this with ground meat.”
Lab-Grown Meat’s Promise
Proponents of lab-grown meat say it will cut down on traditional agriculture, which has been a leading contributor to deforestation, water shortages and contaminated waterways from animal waste, as well as climate change.
An Oxford University study from 2011 concludes lab-grown meat could have greenhouse emissions 96 percent lower compared to traditionally raised livestock. Moreover, proponents of lab-grown meat claim that the suffering of animals would decline dramatically, as they would no longer need to be warehoused and slaughtered. A recently opened 26-story high-rise in China dedicated to the raising and slaughtering of pigs illustrates the current plight of livestock in stark terms.
Scientists may even learn how to tweak lab-grown meat to make it more nutritious. Natural red meat is high in saturated fat and, if it’s eaten too often, can lead to chronic diseases. In lab versions, the saturated fat could be swapped for healthier, omega-3 fatty acids.
But critics say the doubts about lab-grown meat and the possibility it could merge “Brave New World” with “The Jungle” and “Soylent Green” have not been appropriately explored.
A Slippery Slope?
Some academics who have studied the moral and ethical issues surrounding lab-grown meat believe it will have a tough path ahead gaining acceptance by consumers. Should it actually succeed in gaining acceptance, many ethical questions must be answered.
“People might be interested” in lab-grown meat, perhaps as a curiosity, said Carlos Alvaro, an associate professor of philosophy at the New York City College of Technology, part of the City University of New York. But the allure of traditionally sourced meat has been baked – or perhaps grilled – into people’s minds for so long that they may not want to make the switch. Plant-based meat provides a recent example of the uphill battle involved in changing old food habits, with Beyond Meat’s stock prices dipping nearly 80 percent in 2022.
"There are many studies showing that people don’t really care about the environment (to that extent)," Alvaro said. "So I don’t know how you would convince people to do this because of the environment.”
“From my research, I understand that the taste (of lab-grown meat) is not quite there,” Alvaro said, noting that the amino acids, sugars and other nutrients required to grow cultivated meat do not mimic what livestock are fed. He also observed that the multiplication of cells as part of the process “really mimic cancer cells” in the way they grow, another off-putting thought for would-be consumers of the product.
Alvaro is also convinced the public will not buy into any argument that lab-grown meat is more environmentally friendly.
“If people care about the environment, they either try and consume considerably less meat and other animal products, or they go vegan or vegetarian,” he said. “But there are many studies showing that people don’t really care about the environment (to that extent). So I don’t know how you would convince people to do this because of the environment.”
Ben Bramble, a professor at Australian National University who previously held posts at Princeton and Trinity College in Ireland, takes a slightly different tack. He noted that “if lab-grown meat becomes cheaper, healthier, or tastier than regular meat, there will be a large market for it. If it becomes all of these things, it will dominate the market.”
However, Bramble has misgivings about that occurring. He believes a smooth transition from traditionally sourced meat to a lab-grown version would allow humans to elide over the decades of animal cruelty perpetrated by large-scale agriculture, without fully reckoning with and learning from this injustice.
“My fear is that if we all switch over to lab-grown meat because it has become cheaper, healthier, or tastier than regular meat, we might never come to realize what we have done, and the terrible things we are capable of,” he said. “This would be a catastrophe.”
Bramble’s writings about cultured meat also raise some serious moral conundrums. If, for example, animal meat may be cultivated without killing animals, why not create products from human protein?
Actually, that’s already happened.
It occurred in 2019, when Orkan Telhan, a professor of fine arts at the University of Pennsylvania, collaborated with two scientists to create an art exhibit at the Philadelphia Museum of Art on the future of foodstuffs.
Although the exhibit included bioengineered bread and genetically modified salmon, it was an installation called “Ouroboros Steak” that drew the most attention. That was comprised of pieces of human flesh grown in a lab from cultivated cells and expired blood products obtained from online sources.
The exhibit was presented as four tiny morsels of red meat – shaped in patterns suggesting an ouroboros, a dragon eating its own tail. They were placed in tiny individual saucers atop a larger plate and placemat with a calico pattern, suggesting an item to order in a diner. The artwork drew international headlines – as well as condemnation for Telhan’s vision.
Telhan’s artwork is intended to critique the overarching assumption that lab-grown meat will eventually replace more traditional production methods, as well as the lack of transparency surrounding many processed foodstuffs. “They think that this problem (from industrial-scale agriculture) is going be solved by this new technology,” Telhan said. “I am critical (of) that perspective.”
Unlike Bramble, Telhan is not against lab-grown meat, so long as its producers are transparent about the sourcing of materials and its cultivation. But he believes that large-scale agricultural meat production – which dates back centuries – is not going to be replaced so quickly.
“We see this again and again with different industries, like algae-based fuels. A lot of companies were excited about this, and promoted it,” Telhan said. “And years later, we know these fuels work. But to be able to displace the oil industry means building the infrastructure to scale takes billions of dollars, and nobody has the patience or money to do it.”
Alvaro concurred on this point, which he believes is already weakened because a large swath of consumers aren’t concerned about environmental degradation.
“They’re going to have to sell this big, but in order to convince people to do so, they have to convince them to eat this product instead of regular meat,” Alvaro said.
Hidden Tweaks?
Moreover, if lab-based meat does obtain a significant market share, Telhan suggested companies may do things to the product – such as to genetically modify it to become more profitable – and never notify consumers. That is a particular concern in the U.S., where regulations regarding such modifications are vastly more relaxed than in the European Union.
“I think that they have really good objectives, and they aspire to good objectives,” Telhan said. “But the system itself doesn't really allow for that much transparency.”
No matter what the future holds, sometime next year Carnegie Mellon is expected to hold a press conference announcing it has produced a cut of the world’s most expensive beef with the help of a modified piece of consumer electronics. It will likely take place at around the same time UPSIDE chicken will be available for purchase in supermarkets and restaurants, pending the USDA’s approvals.
Abbott, the Carnegie Mellon professor, suggested the future event will be both informative and celebratory.
“I think Carnegie Mellon would have someone potentially cook it for us,” she said. “Like have a really good chef in New York City do it.”