(A guest post by Joanna Scott-Lutyens of NutriEssence)

When you feel that dreaded scratchy throat, vice-like headache or sudden endless sneezing, you know it is typically the onset of a cold or flu. Although guzzling a bunch of vitamin C might seem like the best way to boost your immune system at this time this rarely has the effect of changing the course of the illness, which often leads you to submit to it with a sigh of resignation. You might even reach for cold and flu tablets to ease the symptoms knowing that it will be a battle with every day life for a few days or weeks and you can use all the help you can get.

But what if these symptoms didn’t make a cold or flu inevitable? What if there was another way to support your immune system that didn’t require eating a bag of oranges every day? Would you be interested to find out more?

I’d like to introduce you to your glorious gut bacteria!

Your gut and immunity are in fact inextricably linked. About 70% of your immune system is actually based in your digestive system, and the gut mucosa connects with a large collection of immune cells in the body. These come from what is known as the lymphoid system and are bundles of cells known as Peyer’s patches which work to protect the membranes of the small intestine from infections. They do this by releasing white blood cells known as T cells and B cells to defend from infection. These protect the gut from infection but they also migrate through to the lymphatic system preparing the whole body for an immune attack against a pathogen.

Although your digestive system’s main role is to digest and absorb your food it also has a major role in defence. Have you ever considered that your gut is actually on the outside of your body? If you think about it you are actually open from top to bottom (literally) making your digestive system very vulnerable to attack from the outside.

Other than the specialized immune cells, our friendly bacteria are absolutely vital to protecting our gut walls. When we take probiotics they travel to our gut and adhere to the gut wall and grow in numbers. These little bacteria are like soldiers protecting their fort wall and stopping any pathogen or infections from being absorbed into our blood stream. Sometimes called the ‘barrier effect’, this is a huge part of our immune system, and one we don’t really think of.

As well as this is the nutritional side of immunity. More and more of us are becoming increasingly aware of how important our food is. That is fantastic news, but in order to optimise the use of these wonderful nutrients we need to be absorbing them. The correct function of the gut wall is vital for overall digestion and absorption of foods and again probiotics have a fundamental role in this. Optimised absorption of nutrients is essential for a strong immunity (you can check out the research here).

So all of this sounds wonderful but is there any clinical evidence for this? The answer is yes. One meta-analysis1 found that the average duration of winter illness, and the number of days spent absent from work, were significantly reduced by taking a probiotic, compared to placebo.

Another trial2 looked at immune function in professional rugby players. It was found that the group of players who took a probiotic suffered approximately 40% fewer colds and gastrointestinal infections compared to those who didn’t.

So there are several studies highlighting the value of probiotics for keeping our cold and flu tablet bill down but how do we know which ones to buy? Well, the strain of the probiotic is very important. Different probiotics have different characteristics and are particularly beneficial for different things. In-vitro trials3 to investigate which probiotic strains were especially effective at combating food-borne bugs, found the strains L. acidiphilus UBLA-34 and B. longum UBBL-64 had excellent ability to inhibit Listeria, Yersina as well as a good ability to inhibit E. Coli and Salmonella. These strains of probiotic can be found in OptiBac Probiotics ‘For daily immunity’ (my preferred probiotic).

In another study4 which was run in the winter season, 326 children were randomly given a placebo or the probiotic strains Lactobacillus acidophilus NCFM® in combination with Bifidobacterium lactis Bi-07. Their immunity was monitored and it was concluded that these strains in combination were an effective way to reduce colds, coughs and fever as well as time off school in children between children aged 3-5. These strains can be found in OptiBac Probiotics ‘For every day EXTRA Strength’ which is also a good probiotic for support with more challenging digestive issues.

Want more confirmation that gut bacteria influence your immunity? Remember the last time you were stressed for a while? Did you come down with a cough or a virus you just couldn’t shake off? Stress is known to wreck havoc with gut bacteria, destroying the delicate balance of your microbiota and can be seen in how stress affects your ability to stave off bugs. Some people often get an upset tummy just before they come down with a cold or flu; another indicator that your gut is linked to your health. Antibiotics are also known to destroy not just bad bacteria but healthy bacteria too. It therefore follows that people often suffer from a bout of ill health following a course of antibiotics, again because the gut microbiota, and therefore the immune system is being compromised. These connections again underlie how inextricably connected your gut and immunity is, and therefore the importance of this surprising way to boost your immunity naturally.

It’s never too late to start looking after yourself with these little bacteria.

or more from Joanna Scott-Lutyens , passionate advocate of nutrition for wellbeing, nutritional therapist and founder of NutriEssence, visit www.nutriessence.co.uk and connect with her on Facebook @NutriEssence

To find out more about the probiotics that Joanna recommends check out OptiBac

References:

1.Sarah King et al (2014) Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis.British Journal of Nutrition. July 2014; 112(1): 41–54.

2.Haywood, Brylee A. et al. (2012) Probiotic supplementation reduces the duration and incidence of infections but not severity in elite rugby union players. Journal of Science and Medicine in Sport , Volume 17 , Issue 4 , 356 – 360

3. Laboratory analysis, Unique Biotech Limited, Hyderabad

4.Leyer GJ, et al. (2009) Probiotic effects on cold and influenza-like symptom incidences and duration in children. Official Journal of the American Academy of Pediatrics; Vol. 124, pp. 172-179