Support your microbiome through winter

’Tis the season to be snotty? No thanks, writes Christine Stewart.

As the days get colder (and shorter) it seems that staying healthy and avoiding “germs” is high priority. While the thought of staying home, watching Netflix and sipping hot soup under a blankie seems appealing, dealing with blocked noses, pounding heads and body aches does not.

However, did you know that it is possible to support your immune system (during any season) through your gut? This is good news!

But first, let’s take a brief look at what the immune system is and what it does.

What is the immune system?

When a pathogen or disease-producing microbe has been detected in the body, the network of cells and organs that are our immune system launches its defense mechanisms in order to neutralise the invader and protect healthy cells from infection.

However, when infection does occur, the immune system not only steps up its defense, it also helps the body to recover by leaving behind a permanent memory of the pathogen. This process is called adaptive or acquired immunity.

Overtime, this ongoing recollection and identification of pathogens provides greater protection and results in fewer infections.

How is immunity linked to gut health?

Traditionally, when most people think of the immune system, their first thought is usually inflamed lymph nodes (remember mum feeling behind your ears), white blood cells or perhaps even the spleen. However, the spotlight has recently turned towards our gastrointestinal system, which we now know plays a role in immunity.

Despite being located deep within the body, our gastrointestinal tract is a potential entry site for pathogens wanting to wreak havoc. Our large intestine or colon is host to the largest collection of microorganisms that live in and on us and is commonly termed the gut microbiome. Most of our gut bugs or bacteria are known for their ability to help us digest food, but they also play a vital role in the preparation and training of the immune system.

Our resident bacteria, which is the bacteria who have made our bowel their home, can interact with potential pathogens and provide barrier immunity (protection of the gut lining) through a process called colonisation resistance. This is where a competition for space and nutrients takes place and harmful bacteria are prevented from colonising or living in the gut.

Some of our resident bacteria can also produce substances called short chain fatty acids (SCFAs) such as butyrate, propionate and acetate. These substances have been shown to help intestinal cells mount an immune defence against invading pathogens and prevent inflammation in the gut. They can also boost systemic or whole-body immunity during an immune response by enhancing gut barrier function and recruiting immune cells to fight invading pathogens.

Overall, SCFAs are thought to be highly beneficial for our immune system due to their ability to reduce inflammation and improve the host’s immunity.

How does an imbalanced gut impact immunity?

Put simply, if an imbalance exists, it’s entirely possible that poor immunity could result. This is because not all gut bacteria are able to produce the valuable SCFAs that assist the body to ward off opportunistic pathogens.

We can help our bacteria to produce butyrate, propionate and acetate by consuming an assortment of adequate prebiotics, which are foods that promote the growth of beneficial gut species. For instance, when we supply the microbiome with an array of prebiotics such as fibre, resistant starch and phytochemicals, we support the beneficial bacteria to produce helpful substances that support good health and immunity.

Help your gut health and immunity with diet

The key here is plants! And lots of different types. Like us, it seems variety is the spice of life for our microbes, too.

Adopting a plant-based diet chock-full with fruits, vegetables, nuts, seeds, legumes and whole grains will contribute an array of prebiotics to the microbiome and ultimately strengthen immunity.

When sneezing, coughing and blocked noses seem to be everywhere, try these easy ways to ensure your gut is getting enough prebiotics this winter:

Get into whole grains

• Start the day with a gut nourishing bowl of porridge topped with a mix of your favourite seeds and a shake or two of cinnamon.
• Add some barley to your veggie soup and try a new type of bread to dunk into it, such as seeded or rye bread.
• Try buckwheat, quinoa or brown rice with your favourite curry to mix up your grain choices.

Go for plenty of seasonal vegetables

• Add a few spears of asparagus to your favourite savoury-style breakfast.
• Roast beetroots, pumpkin, sweet potato and Brussels sprouts to create a warm wintery salad.
• Bulk up your bolognese with mushrooms, carrots or cooked red lentils.

Love your legumes

• Choose refried beans instead of meat fillings when next enjoying a Mexican-style dish.
• Relish in some hearty baked beans on whole grain toast.
• Snack on a bowl of freshly cooked edamame.

Snack sensibly

• Enjoy a selection of nuts and seeds with your afternoon cuppa.
• Go for seasonal fruits such as oranges or kiwi fruit for an added dose of vitamin C and a little extra immune boost.
• Add green banana flour to your smoothies to increase the resistant starch content.

Christine Stewart is a Microba coach and nutritionist.