Decoding Stress: What Your Biology Is Really Telling You

Chronic stress is often spoken about in broad terms, yet its impact is anything but uniform. In this exclusive interview, Dr. Fernando Porras, Medical Director at Omics Precision Health, explores how stress is uniquely expressed at a biological level in each individual. From hormonal disruption and immune imbalance to shifts in metabolism and mood, he explains why resilience varies so widely and how advances in omics testing are helping clinicians move beyond symptom management toward truly personalised and data-driven care.

From a precision health perspective, how does chronic stress manifest differently from person to person at a biological level?

The key is to define what chronic stress is, because in general, most people think of psychological or emotional stress. But stress is whatever the body is being stressed by at the biological level. It could be emotional stress, poor sleep, overexertion, lack of exercise, or other factors. All these things cause stress in the body, and that's going to affect a person’s physiology.

However, the impact of stress varies from person to person, as everyone has their own limits and thresholds. It’s important for practitioners to measure the burden of these stresses on the body to understand an individual’s resilience or susceptibility to chronic stress.

There are various ways to measure this. At our clinic, we go beyond standard assessments by combining detailed clinical questioning with multi-layered omics testing, which allows us to understand how different biological systems are responding to stress together, rather than in isolation.

We often hear about cortisol as the “stress hormone.” What actually happens in the body when stress becomes prolonged or dysregulated?

Cortisol often gets a bad rap. It is important as a stress hormone and we need it. For example, it supports the fight-or-flight response and acts as a natural anti-inflammatory. But whenever levels of cortisol remain elevated for a prolonged period or go unchecked, it can have adverse effects, including weight gain, muscle weakness, high blood pressure, and type 2 diabetes.

For the patient, it can feel like their body is trying to suppress inflammation without knowing where it's coming from. In this scenario, testing can reveal whether the patient’s cortisol levels are normal.

How does stress impact key systems such as metabolism, hormones, and the immune system over time?

Chronic stress can disrupt hormonal function and significantly affect the body's hormonal balance by keeping the fight-or-flight response constantly active. Elevated cortisol levels can suppress or inhibit the function of other essential hormones. When cortisol remains high for prolonged periods, it takes precedence over other bodily processes, disrupting the balance of hormones required for metabolic and cognitive health.

When someone pushes themselves to the limit by overworking, getting insufficient sleep, and feeling anxious, their body may show disruption across hormonal, metabolic, and immune systems. It is not always easy for the body to return to normal, and this particularly applies to the immune system, which has a long memory.

Is there much of a relationship between chronic stress and depression?

Chronic stress causes dysregulation of hormones and metabolism, which affects the body's ability to produce and respond to neurotransmitters such as serotonin, dopamine, or oxytocin, which affect mood, emotion, and overall well-being. Chronic stress can desensitize the body to these neurotransmitters, so in the case of serotonin, an individual might lose out on its positive effects on emotion, sleep, and anxiety reduction.

In your clinical experience, what are the most overlooked or misunderstood symptoms of chronic stress?

One of the most overlooked symptoms of chronic stress is the harm it does to the body’s resilience, including its ability to remain healthy and recover from illness. When someone is experiencing chronic stress, they tend to let things slip without noticing, such as exercise, diet, and good quality sleep. When they try to fix these things after experiencing chronic stress, they might find it more difficult than they anticipated, and this is not just from a psychological standpoint. What we see is that the body does not respond in the same way as it did before.

This is often overlooked or misunderstood because many people attribute symptoms such as struggling to lose weight or gain muscle mass to aging, when they may in fact be related to a loss of resilience caused by chronic stress. Similarly, people who have experienced prolonged stress might not associate their weakened immune system with stress, though they will likely be more susceptible to illness and take longer to recover from common infections such as a cold.

How can emerging tools like biomarkers or omics testing help us better understand an individual’s stress response?

There have been significant advances in tests that can indicate chronic stress in recent years. Just a few years ago, testing relied on more general, single time-point blood tests that provided limited information.

At our clinic we have introduced omics testing, which allows us to see what’s going on inside the body and spot patterns. Instead of relying solely on traditional blood markers, omics testing integrates genomics (DNA), proteomics (proteins), and metabolomics (metabolites) to comprehensively map biological systems for biomarker discovery, disease diagnostics, and personalized medicine. Combined, these tests tell us a lot about the patient’s body and how it’s functioning, including genetic predisposition to illness and the current state of their physiology and metabolism.

These tests yield unprecedented amounts of useful data, which clinicians can analyze using AI-based systems to spot patterns and make predictions. We also compare results against large datasets, which allows us to identify patterns and early deviations that would not typically be visible through conventional testing.

With omics, we can also gain a detailed understanding of the impact that chronic stress might have on the patient’s body, including on their brain, heart function, and endocrine system. This allows us to recommend a course of action, including lifestyle changes and treatments tailored to their individual needs.

Sleep, nutrition, and movement are often cited as pillars of stress management. From a scientific standpoint, which has the most immediate impact and why?

While all these areas are important, I would highlight sleep as critical, as it plays a key role in stress management and in most areas of general health. When a patient improves their sleep, it helps to correct problems in other areas, including the endocrine and immune systems, while also reducing feelings of anxiety because the person wakes up feeling rested and in a better frame of mind.

Sleep is vital to the body’s ability to repair itself and clear metabolic waste. It is critically important for the glymphatic system, allowing it to remove metabolic waste, including neurotoxic proteins such as amyloid-beta and tau, which have been linked to Alzheimer's. This system is highly active during deep, slow-wave sleep, where waste clearance increases significantly compared to wakefulness.

What role does the gut-brain connection play in stress, and how can people support it through lifestyle or nutrition?

People used to talk about the gut as being the “second brain,” and for good reason. A significant portion of the body's neurotransmitters, such as serotonin and dopamine, are produced in the gut, which underscores the major role it plays in helping to regulate stress and anxiety.

The gut-brain connection is a complex, bidirectional communication system through which stress can trigger physical symptoms in the digestive tract, while an unhealthy gut can contribute to anxiety and depression. Chronic stress disrupts this gut-brain axis by altering the gut microbiome and increasing intestinal permeability, also known as ‘leaky gut’, which can trigger inflammation, autoimmune conditions, and affect mood, cognition, and stress resilience.

People can support a healthier gut by eating the right types of fiber and natural anti-inflammatory and antioxidant foods such as polyphenols. Good examples include fruits such as apples, grapefruit, blueberries, raspberries, and strawberries. Just like exercise, it’s beneficial to find something you enjoy and fit it into your lifestyle so that it is sustainable, rather than a chore that you eventually stop.

Everyone’s gut is different, which makes it important to define what their balance is. It can be useful to do this with assistance from a qualified health coach, dietitian, or functional medicine doctor. This is another area where our clinic’s omics testing can help to reveal a person’s optimal diet and foods to avoid.

For high-performing individuals with demanding lifestyles, what practical, evidence-based strategies do you recommend to regulate stress daily?

High-performing individuals are often perfectionists who set a very high bar for themselves. But they should learn when they have done enough and stop pushing themselves to the limit all the time. They may need to take a step back and reflect on areas they may have neglected, such as their own health and well-being.

If this is the case, it is important for a high-performing individual to relax and stop treating everything like a competition, because that can lead to burnout and increased chronic stress. Sometimes less is more, and reducing perfectionism can be a healthy step. On a daily basis, this could translate into dedicated time for relaxing activities: time spent with family and friends, a gentle walk, or simply quiet time alone.

In terms of evidence-based strategies, we believe that combining lifestyle changes with a detailed understanding of an individual’s biology allows for a more targeted and sustainable approach to stress management than general recommendations alone.