Supporting the mucosal immune system ahead of the cold and flu season

The mucosal immune system is a remarkable defence network that safeguards the body’s inner surfaces, such as those lining the respiratory, digestive, and urogenital tracts. Read on to find out how you can support your mucosal immune system through nutrition. 

By Neil Bridgeman
Oct 10, 2023 • 6 min read

Our immune system is made up of multiple levels of defence to protect and guard us from the daily onslaught of pathogens and toxins that try to enter our bodies and ultimately cause illness and disease. If our immune system is nourished and operating well, it’s able to repel these pathogens, like bacteria and viruses, and restore things back to normal. However, when our immune system is overloaded, operating at high intensity and just not getting enough support from us by way of nutrients, then we often find ourselves in a cycle of colds, flus and other illnesses especially through the colder months. 

Read on to understand how you can support your immune system, starting with our first line of defence – our mucosa. 

The innate immune system – our first line of defence

Our innate immune system is support by two layers of defence:

1/ Physical barriers like our skin and mucous membranes 

2/ Chemical barriers like sweat, sebum, our stomach acid, tears, mucus, tissue fluids and vaginal bacteria. 

Our mucous membranes which form part of our mucosal immunity play an enormous role in our first line defence system. A keen focus on this part of our immune system can be incredibly supportive in preventing sickness over the winter months. 

What’s the mucosal immune system? 

The mucosal immune system is a remarkable defence network that safeguards the body’s inner surfaces, such as those lining the respiratory, digestive, and urogenital tracts. It is a complex and highly specialised system designed to protect against a barrage of potential threats, including pathogens, allergens, and toxins, that constantly seek entry through these vulnerable spaces.

Composed of a web of immune cells, antibodies, and mucous-secreting cells, this system acts as a vigilant guardian, rapidly identifying and neutralising invaders while maintaining a delicate balance to prevent excessive immune responses.

Its ability to discriminate between harmful intruders and beneficial substances, while ensuring tolerance to harmless commensal microorganisms, highlights just how remarkably adaptable and precise the mucosal immune system is in preserving our overall health and wellbeing.

Ok, got it! So how can nutrition play a role in supporting our mucosa? 

Diet and nutrition play a crucial role in supporting the mucosal immune system’s health and function. A well-balanced diet rich in vitamins, minerals, and antioxidants provides the essential nutrients required for the production of mucosal antibodies and immune cells. 

Nutrients like vitamin C, vitamin D, zinc, and omega-3 fatty acids, for instance, can enhance immune responses and mucosal barrier integrity. Consider adding more of the following to your diet over the coming months:

  • Citrus fruit, kiwis, melons, berries, broccoli, Brussels sprouts, kale, cabbage are all packed full of vitamin C
  • For zinc; lean red and white meats, oysters, firm organic tofu, lentils, oats, shitake mushrooms and most nuts and seeds are all great sources
  • Omega-3 fatty acids are most abundant in oily fish like salmon, mackerel, anchovies, herring, sardines, chia seeds, walnuts, ground flax seeds, flaxseed oil, dark green leafy vegetables
  • Food sources containing vitamin D tend to be scant beyond eggs, salmon and mushrooms and ultimately we need to ensure adequate sun exposure during the sunnier months of the year to build up our stores to support us during winter. For those who have limited sun exposure during the summertime or if you have dark skin – for example you have an African, African-Caribbean or of south Asian background – you may also not make enough vitamin D from sunlight. October is often a good time of year to get your vitamin D levels tested to see if there is any deficiency so that it can be corrected ahead of the cold and flu season. 

Additionally, a diet that includes diverse sources of fibre can promote the growth of beneficial gut bacteria, which can positively influence mucosal immunity. Gut-associated lymphoid tissue, often abbreviated as GALT, is a critical component of the mucosal immune system and serves as a primary defence mechanism in the gastrointestinal tract. It is home to 60% of our immune system, so adequate and diverse fibre intake plays a crucial role in priming our overall immune system. 

Think about the following sources of fibres to include in your diet over the coming months;

  • Ample servings of fruits (1-2 servings per day) and vegetables (5-6 servings per day)
  • Snacking on nuts and seeds 
  • Aiming for a serving of pulses and legumes each day
  • Incorporating unrefined wholegrains like; brown rice; pearled spelt, quinoa, barley, oats, millet into your diet

Saving the simplest tactic for last…staying well hydrated!

Proper hydration helps ensure that mucous membranes remain moist and functional. These mucous membranes serve as a physical barrier against pathogens and irritants, and they are also involved in trapping and eliminating potential threats. Insufficient hydration can lead to dry and compromised mucous membranes, making it easier for pathogens to penetrate and cause infections. Additionally, well-hydrated mucous membranes are more effective at producing mucus, which can help trap and eliminate pathogens.

I recommend aiming for at least 1.5 – 2 litres per day of water. That can also include non-caffeinated herbal teas which are nice and warming during the cooler months and offer a multitude of herbally-health benefits too. My favourites are; chamomile, lemon balm, hawthorn berry, elderberry & echinacea and dandelion.

In summary…

So there you have it – a few simple tactics to prime your mucosal immune system to set you up for success this cold and flu season. Remember:

  • Ample sources of vitamin C, zinc, vitamin D and omega-3 fatty acids
  • Consider testing your vitamin D levels if you suspect they could be low or at high risk of vitamin D deficiency
  • Aim for plenty of fibre and diversify your sources
  • Stay well hydrated through the winter months


DISCLAIMER: The information provided on this website is for informational purposes only and should not be used for diagnosis. It is not intended as a substitute for advice from your GP or other qualified health practitioner.

Recent articles