The Gut-Immune Axis
We all recognise that feeling – the sudden tickle in your throat or the onset of the sniffles. Whether it’s a shift in the seasons or just a particularly busy time of year, we often scramble for the usual remedies to stay well.
And for many of us, the first sign of a cold means reaching for an orange. While oranges are a great source of vitamin C (ascorbic acid), the idea that they can prevent a cold is a common misconception. Research suggests that taking vitamin C supplements regularly doesn’t stop most people from catching a cold, although it may slightly reduce the duration and severity of symptoms.1
But did you know that looking after your gut health actually can support your immune system?
Welcome to the world of the gut-immune axis:
What is the Gut-Immune Axis?
It may come as a surprise, but your digestive system and your immune system are closely connected. In fact, around 70-80% of your immune cells are found in the gut!2
The “gut-immune axis” is the constant, two-way conversation between the trillions of microbes living in your digestive tract (your microbiome) and your immune cells. Think of your gut bacteria as a coach for your immune system. They help to “educate” your immune cells, teaching them the difference between harmless visitors (like the food you eat) and unwanted invaders (like everyday viruses).3
When your gut is happy and filled with a diverse community of beneficial bacteria, it sends signals that keep your immune system balanced and ready to defend you. When it’s out of balance, your immune defences can struggle to respond effectively.
Top Tips for Supporting the Gut-Immune Axis
Eat a Gut-Friendly Diet:
Focus on incorporating fibre-rich foods, which act as a fuel for good gut bacteria. Aim for 30 or more different plant-based foods a week, as this variety helps to build a diverse and healthy gut community. 4
These can include fruit, vegetables, wholegrains, beans, lentils, nuts, seeds, herbs and spices. Finally, include fermented foods such as yoghurt, fermented milk drinks, kimchi and sauerkraut.
Prioritise Sleep:
Just like you, your gut microbes also follow a circadian rhythm, a natural 24-hour pattern influenced by your body’s internal clock. A lack of sleep can disrupt this rhythm and alter the balance of your microbiome, which in turn can lower your immune defences. Aiming for 7 to 9 hours of quality sleep each night gives both your gut and your immune system the critical downtime they need to repair and regenerate.5
Stay Active:
Exercise can help to promote healthy bacteria in the gut, which can in turn reduce inflammation and support immune function.6 The key is to find something you enjoy doing, or combine it with something you already do, such as walking the dog or having a dance during the commercial break of your favourite tv programme.
Manage Stress Levels:
It’s important to find ways to manage everyday stress through activities such as meditation, yoga, walking in nature and breathing exercises. Research suggests that prolonged psychological stress may negatively affect the composition of the gut microbiota through several pathways, including an increased release of stress hormones and inflammation.7
LYG Recipes to Support Immune Health:
- Poke bowl with sticky miso aubergine and kimchi
- Quinoa with salmon and pesto dressing
- Simple red lentil dal
References:
- Hemilä et al. (2013) Cochrane Database Syst Rev, 2013(1), CD000980
- Furness et al. (1999) Am J Physiol 277(5): G922–G928
- Zheng et al. (2020) Cell Res 30: 492–506
- McDonald et al. (2018) mSystems 3(3): e00031-18
- Madison et al. (2019) Curr Opin Behav Sci 28: 105–110
- Monda et al. (2017) Oxid Med Cell Longev 2017: 3831972
- Besedovsky et al. (2012) Pflügers Arch 463: 121–137