Gut health - beyond what you eat

Written by: Clarissa Lenherr


Healf Journal

The human gut, home to trillions of microorganisms, plays a crucial role in pretty much every aspect of our health. And while nutrition undeniably plays a pivotal role in maintaining a healthy gut, it’s crucial to understand that gut health extends far beyond just what we eat. Achieving great gut health involves a diverse interplay of lifestyle factors, nervous system health, and even social influences.

Written by Registered Nutritionist and Gut Health Expert  Clarissa Lenherr.

The impact of stress

Ever get twinges and butterflies in your stomach? Feel as though your stomach is tied in knots? Changes in your bowel movements, unrelated to food changes? Stress is one of the main drivers and triggers of digestive symptoms.

The body’s response to stress is mediated through the hypothalamic-pituitary-adrenal (HPA) axis. When someone experiences stress, the HPA axis is activated, leading to the release of cortisol and other stress hormones. These hormones prepare the body for a 'fight or flight' response by redistributing energy and resources to essential functions, such as to blood flow and muscle function, leaving the digestive system under-resourced.

One significant impact of stress hormones is on gut motility. Under stress, the rate of peristalsis, the wave-like contractions that move food through the digestive tract, can change. This can result in either accelerated transit times, causing diarrhoea, or slowed transit times, leading to constipation. In addition, cortisol and other stress hormones can increase intestinal permeability, a condition often referred to as "leaky gut." This allows bacteria and toxins to pass from the gut into the bloodstream, potentially triggering systemic inflammation.

Stress can also have an impact on the gut microbiome, the diverse community of microorganisms residing in the digestive system. A healthy gut microbiome is crucial for maintaining digestive health, but stress can disrupt this balance, leading to dysbiosis (an imbalance in the harmony of these microorganisms). And dysbiosis is associated with a range of symptoms, including bloating, abdominal pain, irregular bowel movements and much more.

The solution, work on your stress, but easy for me to say, much harder to put into practice. Here are some great places to start:

  • Breathe - So many of us don't take time out during our hectic daily lives to stop and take a deep breath. Deep breathing exercises activate the parasympathetic nervous system, often referred to as the "rest and digest" response. By engaging in slow, deep breathing techniques, such as diaphragmatic breathing or paced breathing, we stimulate the vagus nerve, which also helps regulate our digestion.

  • Regular exposure to nature - Studies have found a correlation between spending more time outdoors, especially in green spaces, and reduced stress levels. Going for a walk in nature is one of my favourite (and free) ways to calm the nervous system

  • Support your body with adaptogens -  Adaptogens adapt to your bodies stress responses, and may help with stress resilience. My favourites are Rhodiola and Ashwagandha

Sleep - the unsung hero

Many of us are aware that sleep is a vitally important part of our every day and contributes to various aspects of our health, but not enough people talk about the impact of sleep on our digestive system and gut health.

Wonder why you are more hungry after a bad nights sleep? Studies have suggested that just one night of bad sleep can increase our hunger hormone ghrelin! And when we are more hungry, there is an increased likelihood that we are going to reach for satiating and satisfying foods, which can often be choices that are high in sugar or ultra processed foods. Long term consumption of these foods can have an impact on our microbiome health, and for some people even trigger digestive symptoms.

In addition, the health of our microbiome might actually have a role on our sleep quality. One study found that a more diverse microbiome resulted in better sleep efficiency and longer sleep time.

So how can we get the best night’s sleep?

  • Reduce blue lights before bed – these interrupt your circadian rhythm that governs your wake and sleep cycles

  • Consider a magnesium glycinate supplement – I like the Pure Encapsulations Magnesium Glycinate for my clients, and recommend taking it with dinner for a deeper, more quality rich sleep

  • Avoid caffeine in the later part of the day – caffeine interferes with sleep by blocking adenosine receptors, increasing alertness, delaying sleep onset and disrupting sleep architecture. The cut off I normally recommend is 2pm.

Gut moves

Regular physical activity helps in enhancing gut motility, reducing the risk of constipation and promoting regular bowel movements. This is because exercise stimulates the muscles of the gastrointestinal tract, supporting the movement of food through the digestive system.

When it comes to the microbiome and exercise, observational studies seem to suggest that increased levels of fitness are correlated with microbial diversity – a good thing!

So does that mean we should be pounding the treadmill for an hour every day? Absolutely not. As we know, stress can impact our digestive health, and intense exercise can put our body into a fight or flight response.

The key here is balance. Daily movement is wonderful for every aspect of our health, but that doesn’t mean you need to book into daily classes where you are being screamed at to run faster whilst looking into a flat wall. That I would say is counterproductive! 

The way we eat

Eating habits, including meal timing, portion sizes, the speed we eat at and external distractions at meal times, can all significantly affect digestive processes and contribute to various gut symptoms – the two most common ones I see in practice is acid reflux and bloating.

Chewing is our first step of digestion. It breaks down food into smaller pieces, increasing the surface area for enzymes to work on, it stimulates the production of saliva, which contains enzymes like amylase that start breaking down carbohydrates in the mouth, and it stimulates stomach acid production. So why don’t we do more of it…

Distractions at meal times is a major culprit. When we eat our meals distracted, we are less likely to pay attention to our body’s hunger and satiety signals, which can lead to overeating. Distracted eating also tends to coincide with faster eating speeds, which can leading to swallowing air, contributing to gas and bloating.

How can we work on the way we eat to support our gut health and reduce the likelihood of digestive symptoms? Try these 3 eating habits:

  • Put your fork and knife down between each bite

  • Chew as many mouthfuls as you can remember (or be bothered to!) until the consistency of apple puree

  • Put away the laptops, phones and turn off the TV. Take a moment to enjoy your meal and activate your senses.

Get socialising

Who would have thought that people you do (or don’t!) hang out with, can impact your digestive health? Perhaps there is something to say that you have a gut feeling, even when it comes to people!

Studies have shown that those who have strong social networks tend to have a more diverse range of gut bacteria. Close contact with family members, friends, and even pets can expose us to a broader range of microbes, promoting microbial diversity within the gut.

My top tip – pretty obvious but get friendly!


Clarissa is the founder of My IBS Solution – the UK's pioneering online programme tailored specifically for people battling IBS.

Designed by gut health nutritionist Clarissa Lenherr, this comprehensive programme offers a holistic approach to managing IBS symptoms, all from the comfort of your own home. Say goodbye to generic solutions and hello to long-term, digestive relief.

This article is for informational purposes only, even if and regardless of whether it features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The views expressed in this article are the views of the expert and do not necessarily represent the views of Healf