These gut health tweaks will get you through winter bug season

Give your gut health an extra boost with these recipes, or try a whole winter gut health reset . Alternatively, these foods might help if you already have a cold…

Did you know that, on average, adults catch the common cold 2-3 times a year, and children 5-8 times a year? While there’s no cure for winter bugs like colds, you can still lower your risk of getting sick and shorten the length and severity if you do catch something.

Around 70 per cent of immune cells exist in your gut, meaning your gut plays a key role in your immunity through what we call the gut-immune connection. Your microbes teach your immune cells what they need to protect you against (for instance, flu-causing viruses) and what is safe (e.g. the protein in milk). My colleagues at King's College London found that people who ate a more varied diet full of plants (which nourish your gut bacteria) had up to 40 per cent lower risk of becoming unwell with certain viruses. But it’s not just the foods you eat that can have an impact on your gut microbiome…

Here are 5 small tweaks to support against those winter bugs:

1. Get smart with supplements

Vitamin D is a supplement worth considering, not only for directly supporting your immune function but also for your gut health, as it helps to strengthen your gut lining. Our main source of vitamin D is sunlight, so limited daylight in autumn and winter makes it challenging to maintain adequate levels (particularly in the UK). That’s why NHS guidance recommends everyone take at least 10 micrograms per day through the winter. Vitamin D3 (cholecalciferol) is the most effective form for raising your levels, according to a review of 20 studies (compared to vitamin D2, often found in plant foods like mushrooms). Also, vitamin D is fat-soluble, meaning it’s best taken with a meal that includes healthy fats to aid absorption. Think oily fish (like salmon or mackerel), extra virgin olive oil, avocado, nuts, seeds or full-fat kefir yogurt.

On the probiotic front, you need to get specific about the strains (the scientific name for each different bacteria) that you choose. The idea that you should take a probiotic for general gut health is outdated (and the science doesn’t support this approach). Instead, you should be looking at the right strain, at the right time (for the specific health issue, e.g. immune support), in the right format. For example, the combination of Lactobacillus rhamnosus GG (LGG) and Bifidobacterium BB-12 has been shown in clinical trials to reduce the severity of colds and flu by over 30 per cent and cut duration by around two days. In infants, this exact formulation of the two strains has been found to halve the risk of infections compared with placebo.

2. De-stress and digest

Stress can strangle your digestive system and has even been shown in studies to increase your risk of colds. A simple trick? Try just 10 minutes of belly breathing, a body scan, a family walk or even some simple yoga – whatever works for you and can easily fit into your day.

3. Chew it over

Even if you’re eating all the right foods, if you’re not chewing properly, you might not reap the immune-nourishing rewards. It might sound too simple to matter, but there’s real science behind it. Chewing thoroughly essentially ‘activates’ enzymes in your saliva, helping your body break down food and absorb nutrients more effectively, and supports that gut-immune connection. Aim for 20-30 chews per bite, depending on texture or start small by adding just two extra chews per week and building from there.

4. Step up your sleep

With parties and family gatherings coming up, your regular sleep routine might fall by the wayside. But skimping on sleep can affect more than just your energy levels – it can also impact your gut microbes. During deep sleep, your body produces and releases important immune cells and signalling proteins called cytokines, which help fight infection and reduce inflammation. When sleep is cut short or disrupted, these processes can be compromised, making your defences less effective. Research shows that even a couple of nights of poor sleep can cause changes in the balance of your gut microbes, key players in regulating your immune system. Try to keep your sleep schedule as regular as possible, but if that feels unrealistic with your plans (or personal responsibilities) over the season, focus on the other tweaks such as destressing and diet instead.

5. Embrace the 'super six'

Thanks to that gut-immune connection we covered earlier, keeping your microbiome well nourished is key. One of the simplest ways to do this is to focus on plant diversity, with variety across what I call the 'super six' (fruits, vegetables, legumes, wholegrains, nuts, seeds, herbs and spices). Think of each plant as a unique fertiliser, feeding the trillions of different types of bacteria in your gut. The more variety, the stronger your army of microbes, which can support your immune resilience this winter.

You should be aiming to eat foods from each group daily. Small daily changes, like adding mixed seeds to your porridge topping, stirring a portion of lentils into your bolognese or adding frozen vegetables like cauliflower to your smoothies, can all make a real difference. And that leads me nicely onto the 10 foods to support your gut-immune connection...

Here are the 10 best gut-immune supporting foods to eat

1. Broccoli – It’s rich in sulforaphane and fibre. Sulforaphanes have been shown to boost antioxidant defence and the fibre is converted into short-chain fatty acids by your gut bacteria, which help to reduce inflammation.
2. Blueberries – They’re packed with anthocyanins – antioxidants that are linked with reducing inflammation and supporting the gut-immune link.
3. Oily fish (salmon, mackerel, sardines) – High in omega-3s (EPA/DHA), these help to regulate immune cell signalling.
4. Carrots – These are a great source of beta-carotene (the vitamin A precursor). Vitamin A helps maintain your skin and gut lining barrier, your body’s first line of defence against cold and flu.
5. Almonds – These provide vitamin E, an antioxidant that has been shown to protect immune cells from oxidative stress.
6. Garlic – If you slice or crush it and leave it to sit for around 10 minutes before eating, this allows the inactive compound, alliin, to be converted into the active allicin, which has been linked in studies to many of its health benefits, including fighting viruses and shortened cold duration.
7. Lentils – These are a good plant-based source of zinc, a mineral critical for immune cell development, wound healing and resistance to infections. Zinc deficiency is directly linked to impaired immunity.
8. Mushrooms (especially shiitake, maitake, reishi) – These contain beta-glucans, types of fibres that in lab studies have been shown to help “train” immune cells and support antibody production.
9. Kefir – This delivers a diverse range of gut microbes along with calcium, which is essential for the functioning of various immune-regulating cells.
10. Red peppers – These are one of the richest natural sources of vitamin C, containing even more than oranges. Vitamin C supports your white blood cells, which explains why it has been linked to supporting respiratory health.

Dr Megan Rossi, PhD, Rd, APD is an internationally renowned gut health scientist with an award-winning PhD in probiotics, dietitian, nutritionist and best-selling author with a mission to inspire and transform everyone’s gut health using the latest science.

She is a research fellow at King’s College London and is the founder of The Gut Health Doctor, The Gut Health Clinic, Bio&Me and SMART STRAINS®.

Go to theguthealthdoctor.com | @theguthealthdoctor