A Continuous Sensor for Broad-Spectrum Metabolic Monitoring Could Help Unlock the Gut-Brain Link
Inspired by natural metabolic pathways, a novel "TMR" sensor provides ongoing monitoring of multiple metabolites — up to thousands.
A research team from the University of California, working with colleagues at the Stanford University School of Medicine, has come up with a sensor capable of monitoring a living creature's metabolism — using natural biochemical processes to track thousands of metabolites, the compounds involved in the process of living.
"To understand how metabolites affect biological processes or reflect health, we need to monitor different groups of metabolites based on our specific interest," explains senior corresponding author Sam Emaminejad of the team's work. "So we aimed to develop a sensor platform that can be applied to a wide range of metabolites while ensuring reliable operation in the body — and for that, we tapped into natural metabolic processes."
Traditionally, attempts at tracking metabolic processes have relied on taking samples for resource-intensive processing in the lab — providing only a snapshot in time. Sensors capable of continuous monitoring have had to pick one or two metabolic compounds to target, typically focusing on blood sugar levels. The team's new "tandem metabolic reaction-based sensors" (TMRs), though, are claimed to both work continuously and be able to monitor multiple metabolites simultaneously — up to thousands, potentially.
"Decades of research have mapped natural metabolic pathways linking metabolites to specific enzymatic reactions," Emaminejad explains. "By adapting carefully selected enzymes and cofactors for different functions, our electrodes replicate these complex reactions, enabling reliable detection of a far broader set of metabolites than conventional sensors. The robustness comes from evolution itself — enzymes and cofactors, refined over tens of millions of years, are highly sensitive, specific, and stable. We're harnessing nature’s own blueprint and molecular machinery to track the very biochemical processes they sustain."
"The TMR electrode has additional special features for high-performance biosensing," adds co-first author Xuanbing Cheng. "Made from single-wall carbon nanotubes, it offers a large active area for loading enzymes and cofactors. Reactions occur efficiently at low voltage, reducing undesired side reactions while maximizing the utility of enzyme activity. This allowed us to achieve exceptionally high signal-to-noise ratio measurements across a wide range of applications."
The team is hoping to see the technology adopted for use in diagnosis, monitoring, and treatment of a variety of metabolic and cardiovascular disorders, for drug development, and even industrially — monitoring the yield and efficiency of engineered microbes, for example. The hardware may even help to unlock the secret of how the gut and the brain influence each other. "We're finally equipped to test important hypotheses that lacked key data," Emaminejad claims, "helping us better understand how gut activity impacts overall health, from driving inflammation and affecting mental well-being to shaping chronic disease progression."
The team's work is published in the Proceedings of the National Academy of Sciences (PNAS) under open-access terms.
Main article image courtesy of Xuanbing Cheng and Zongqi Li/Emaminejad Lab.
