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.”
On today’s podcast episode, I had a chance to speak with Shai Efrati, a physician and professor in the schools of medicine and neuroscience at Tel Aviv University. Efrati also directs the Sagol Center for Hyperbaric Medicine and Research, and our conversation in this episode focuses on the potential health benefits of hyperbaric oxygen therapy.
Efrati's studies point to a connection between the use of hyperbaric chambers and improvements for a range of health problems such as Long Covid, strokes and traumatic brain injuries. Plus, Efrati has an early line of research suggesting that hyperbaric oxygen therapy could help protect against cognitive decline in healthy people and perhaps even slow down the overall aging process.
We talk about what’s going in on the body during hyperbaric oxygen therapy that could possibly lead to transformative benefits for patients, some of whom had searched for treatments previously and come up empty. We also discuss exactly where Efrati is with this line of inquiry, both what his studies have shown and the great deal of additional research that’s needed before the healthcare system can and should fully embrace hyperbaric oxygen therapy.
Efrati and I talk about why you can’t just go on Amazon and buy something that says hyperbaric – the only way it can have a positive effect is if you access the real version of the chamber and use it correctly under the supervision of a knowledgeable physician.
I also ask Efrati what we know about the short- and long-term risks for those who follow the research-based protocol on a regular basis. And what about accessibility to people without a lot of extra cash to spend on their health? Efrati is already rolling out this therapy at a small number of specialized clinics in places like the Villages retirement community in Florida.
Shai Efrati
A vaccine for Lyme disease could be coming. But will patients accept it?
For more than two decades, Marci Flory, a 40-year-old emergency room nurse from Lawrence, Kan., has battled the recurring symptoms of chronic Lyme disease, an illness which she believes began after being bitten by a tick during her teenage years.
Over the years, Flory has been plagued by an array of mysterious ailments, ranging from fatigue to crippling pain in her eyes, joints and neck, and even postural tachycardia syndrome or PoTS, an abnormal increase in heart rate after sitting up or standing. Ten years ago, she began to experience the onset of neurological symptoms which ranged from brain fog to sudden headaches, and strange episodes of leg weakness which would leave her unable to walk.
“Initially doctors thought I had ALS, or less likely, multiple sclerosis,” she says. “But after repeated MRI scans for a year, they concluded I had a rare neurological condition called acute transverse myelitis.”
But Flory was not convinced. After ordering a variety of private blood tests, she discovered she was infected with a range of bacteria in the genus Borrelia that live in the guts of ticks, the infectious agents responsible for Lyme disease.
“It made sense,” she says. “Looking back, I was bitten in high school and misdiagnosed with mononucleosis. This was probably the start, and my immune system kept it under wraps for a while. The Lyme bacteria can burrow into every tissue in the body, go into cyst form and become dormant before reactivating.”
The reason why cases of Lyme disease are increasing is down to changing weather patterns, triggered by climate change, meaning that ticks are now found across a much wider geographic range than ever before.
When these species of bacteria are transmitted to humans, they can attack the nervous system, joints and even internal organs which can lead to serious health complications such as arthritis, meningitis and even heart failure. While Lyme disease can sometimes be successfully treated with antibiotics if spotted early on, not everyone responds to these drugs, and for patients who have developed chronic symptoms, there is no known cure. Flory says she knows of fellow Lyme disease patients who have spent hundreds of thousands of dollars seeking treatments.
Concerningly, statistics show that Lyme and other tick-borne diseases are on the rise. Recently released estimates based on health insurance records suggest that at least 476,000 Americans are diagnosed with Lyme disease every year, and many experts believe the true figure is far higher.
The reason why the numbers are growing is down to changing weather patterns, triggered by climate change, meaning that ticks are now found across a much wider geographic range than ever before. Health insurance data shows that cases of Lyme disease have increased fourfold in rural parts of the U.S. over the last 15 years, and 65 percent in urban regions.
As a result, many scientists who have studied Lyme disease feel that it is paramount to bring some form of protective vaccine to market which can be offered to people living in the most at-risk areas.
“Even the increased awareness for Lyme disease has not stopped the cases,” says Eva Sapi, professor of cellular and molecular biology at the University of New Haven. “Some of these patients are looking for answers for years, running from one doctor to another, so that is obviously a very big cost for our society at so many levels.”
Emerging vaccines – and backlash
But with the rising case numbers, interest has grown among the pharmaceutical industry and research communities. Vienna-based biotech Valneva have partnered with Pfizer to take their vaccine – a seasonal jab which offers protection against the six most common strains of Lyme disease in the northern hemisphere – into a Phase III clinical trial which began in August. Involving 6,000 participants in a number of U.S. states and northern Europe where Lyme disease is endemic, it could lead to a licensed vaccine by 2025, if it proves successful.
“For many years Lyme was considered a small market vaccine,” explains Monica E. Embers, assistant professor of parasitology at Tulane University in New Orleans. “Now we know that this is a much bigger problem, Pfizer has stepped up to invest in preventing this disease and other pharmaceutical companies may as well.”
Despite innovations, patient communities and their representatives remain ambivalent about the idea of a vaccine. Some of this skepticism dates back to the failed LYMErix vaccine which was developed in the late 1990s before being withdrawn from the market.
At the same time, scientists at Yale University are developing a messenger RNA vaccine which aims to train the immune system to respond to tick bites by exposing it to 19 proteins found in tick saliva. Whereas the Valneva vaccine targets the bacteria within ticks, the Yale vaccine attempts to provoke an instant and aggressive immune response at the site of the bite. This causes the tick to fall off and limits the potential for transmitting dangerous infections.
But despite these innovations, patient communities and their representatives remain ambivalent about the idea of a vaccine. Some of this skepticism dates back to the failed LYMErix vaccine which was developed in the late 1990s before being withdrawn from the market in 2002 after concerns were raised that it might induce autoimmune reactions in humans.
While this theory was ultimately disproved, the lingering stigma attached to LYMErix meant that most vaccine manufacturers chose to stay away from the disease for many years, something which Gregory Poland, head of the Mayo Clinic’s Vaccine Research Group in Minnesota, describes as a tragedy.
“Since 2002, we have not had a human Lyme vaccine in the U.S. despite the increasing number of cases,” says Poland. “Pretty much everyone in the field thinks they’re ten times higher than the official numbers, so you’re probably talking at least 400,000 each year. It’s an incredible burden but because of concerns about anti-vax protestors, until very recently, no manufacturer has wanted to touch this.”
Such was the backlash surrounding the failed LYMErix program that scientists have even explored the most creative of workarounds for protecting people in tick-populated regions, without needing to actually vaccinate them. One research program at the University of Tennessee came up with the idea of leaving food pellets containing a vaccine in woodland areas with the idea that rodents would eat the pellets, and the vaccine would then kill Borrelia bacteria within any ticks which subsequently fed on the animals.
Even the Pfizer-Valneva vaccine has been cautiously designed to try and allay any lingering concerns, two decades after LYMErix. “The concept is the same as the original LYMErix vaccine, but it has been made safer by removing regions that had the potential to induce autoimmunity,” says Embers. “There will always be individuals who oppose vaccines, Lyme or otherwise, but it will be a tremendous boost to public health to have the option.”
Vaccine alternatives
Researchers are also considering alternative immunization approaches in case sufficiently large numbers of people choose to reject any Lyme vaccine which gets approved. Researchers at UMass Chan Medical School have developed an artificially generated antibody, administered via an annual injection, which is capable of killing Borrelia bacteria in the guts of ticks before they can get into the human host.
So far animal studies have shown it to be 100 percent effective, while the scientists have completed a Phase I trial in which they tested it for safety on 48 volunteers in Nebraska. Because this approach provides the antibody directly, rather than triggering the human immune system to produce the antibody like a vaccine would, Embers predicts that it could be a viable alternative for the vaccine hesitant as well as providing an option for immunocompromised individuals who cannot produce enough of their own antibodies.
At the same time, many patient groups still raise concerns over the fact that numerous diagnostic tests for Lyme disease have been reported to have a poor accuracy. Without this, they argue that it is difficult to prove whether vaccines or any other form of immunization actually work. “If the disease is not understood enough to create a more accurate test and a universally accepted treatment protocol, particularly for those who weren’t treated promptly, how can we be sure about the efficacy of a vaccine?” says Natasha Metcalf, co-founder of the organization Lyme Disease UK.
Flory points out that there are so many different types of Borrelia bacteria which cause Lyme disease, that the immunizations being developed may only stop a proportion of cases. In addition, she says that chronic Lyme patients often report a whole myriad of co-infections which remain poorly understood and are likely to also be involved in the disease process.
Marci Flory undergoes an infusion in an attempt to treat her Lyme disease symptoms.
Marci Flory
“I would love to see an effective Lyme vaccine but I have my reservations,” she says. “I am infected with four types of Borrelia bacteria, plus many co-infections – Babesia, Bartonella, Erlichiosis, Rickettsia, and Mycoplasma – all from a single Douglas County Kansas tick bite. Lyme never travels alone and the vaccine won’t protect against all the many strains of Borrelia and co-infections.”
Valneva CEO Thomas Lingelbach admits that the Pfizer-Valneva vaccine is not perfect, but predicts that it will still have significant impact if approved.
“We expect the vaccine to have 75 percent plus efficacy,” he says. “There is this legacy around the old Lyme vaccines, but the world is very, very different today. The number of clinical manifestations known to be caused by infection with Lyme Borreliosis has significantly increased, and the understanding around severity has certainly increased.”
Embers agrees that while it will still be important for doctors to monitor for other tick-borne infections which are not necessarily covered by the vaccine, having any clinically approved jab would still represent a major step forward in the fight against the disease.
“I think that any vaccine must be properly vetted, and these companies are performing extensive clinical trials to do just that,” she says. “Lyme is the most common tick-borne disease in the U.S. so the public health impact could be significant. However, clinicians and the general public must remain aware of all of the other tick-borne diseases such as Babesia and Anaplasma, and continue to screen for those when a tick bite is suspected.”