Written by Gauri Yardi
What do a cold, depression, and hayfever have in common? If you said “they’re all health conditions”, or even “they’re all inflammatory health conditions”, you would be right. However, there is something more unusual that connects the three.
All three are influenced by your gut microbiome, the microorganisms that call your digestive tract ‘home’. You may be wondering how these tiny gut inhabitants could have any bearing on your throat, joints, and/or brain. In this article, we will find out how your gut influences these seemingly unrelated areas, as well as how to prevent your gut from making you sick, sad or inflamed.
Cold-Busting Colleagues: Your Gut and Immune System Work Hand-in-Hand
Your immune system’s main job is to defend you from pathogens (disease-causing microorganisms). Since pathogens are typically inhaled or swallowed, it makes sense for the immune system to concentrate on your respiratory and digestive tracts. In fact, 70% of the immune system is housed in your gut.1 It lies beneath the lining of your intestines, ready to spring into action if a pathogen enters your gut, to try to prevent you getting sick.
By contrast, some bacteria have a positive influence on your immune system. A healthy gut microbiome interacts with the intestinal immune system in ways that increase your body’s immune defences.
However, a microbiome out of balance, which does not contain high levels of beneficial bacteria, is less likely to help you resist infection, including colds and flu (click here to read more about what might upset your gut microbiome).
Fortunately, certain strains (types) of probiotic bacteria improve the bacterial balance in your gut, with beneficial flow-on effects for your immune system. Lactobacillus rhamnosus (LGG®),2 Lactobacillus paracasei (8700:2) and Lactobacillus plantarum (HEAL 9)3 all stimulate the immune system and improve resistance to infection. In fact, the combination of 8700:2 and HEAL 9 has been shown to reduce the severity and duration of common cold symptoms.4 If you struggle with frequent colds and flu, working with a natural healthcare Practitioner to strengthen your gut microbiome may help.
A healthy gut microbiome interacts with the intestinal immune system in ways that increase your body’s immune defences. However, a microbiome out of balance, which does not contain high levels of beneficial bacteria, is less likely to help you resist infection, including colds and flu (click here to read more about what might upset your gut microbiome).
Jumping at Shadows: The Overactive Immune System
Another possible consequence of poor gut bacterial balance is inflammation, a key feature of autoimmune (e.g. rheumatoid arthritis) and allergic disease (e.g. hayfever). In these conditions, the immune system misidentifies harmless substances as threats, and launches an immune response against them. The resulting inflammation creates the symptoms you associate with allergy and autoimmunity, e.g. a blocked nose and watering eyes in hayfever, or joint pain and swelling in rheumatoid arthritis.
Fortunately, certain probiotic strains, namely LGG® and Lactobacillus paracasei (LP-33®), can stimulate your immune system to produce anti-inflammatory compounds, reducing inflammation and symptoms. For example, research in hundreds of people has shown that LP-33® significantly improves hayfever symptoms.5,6 Interestingly, LGG®, when taken during pregnancy and breastfeeding, can reduce the incidence of eczema (an inflammatory skin disease) in children, by supporting the healthy development of the gut microbiome and the immune system.7 If your immune system is in overdrive, make an appointment with a natural healthcare Practitioner to help bring it back into line.
Gut Feelings: How Bacteria Make or Break Your MoodMore and more research is supporting an unexpected cause of depression: inflammation. Specifically, inflammation throughout the body (known as systemic inflammation), and even inflammation of the brain, may contribute to depression.
As you have already learned, the interaction between bad gut bacteria and the immune system can cause inflammation. However, did you know that the inflammatory chemicals released within your gut can also cause an inflammatory response in your brain?
If gut inflammation can influence mood, you may be wondering if specific probiotics can improve mood or reduce the symptoms of depression. While this is a hot topic in scientific research, we do not currently know which specific probiotic strains can influence mood. However, a good start in supporting healthy mood is taking steps to reduce inflammation in the body.
What we do know is maximising your gut health, e.g. by eating plenty of fibre-rich wholefoods (to provide your gut bacteria with their preferred food), can also increase the numbers of good bacteria, which is the best way to influence your mood via your gut. If your bacterial balance has become disrupted due to a stomach bug, antibiotics, or other causes, strains which support beneficial bacteria, such as LGG®, Saccharomyces cerevisiae var. boulardii, and Bifidobacterium animalis ssp lactis (BB-12®) may help improve the composition of your gut microbiome.
Great Health is All in the Gut
By interacting with your immune system, your gut bacteria influences your ability to resist infection, reduce inflammation, and maintain a healthy mood. If you are wondering whether your gut may be making you sick, sad or inflamed, make an appointment with a natural healthcare Practitioner today. Together, you can assess your bacterial balance, and make a plan to improve your specific symptoms.
References1 Gill HS. Probiotics to enhance anti-infective defences in the gastrointestinal tract. Best Pract Res Clin Gastroenterol. 2003;17(5):755-773. doi: 10.1016/s1521-6918(03)00074-x.
2 Feleszko W, Jaworska J, Rha RD, Steinhausen S, Avagyan A, Jaudszus A, et al. Probiotic-induced suppression of allergic sensitization and airway inflammation is associated with an increase of Tregulatory-dependent mechanisms in a murine model of asthma. Clin Exp Allergy. 2007;37(4):498-505. doi: 10.1111/j.1365-2222.2006.02629.x.
3 Lavasani S, Dzhambazov B, Nouri M, Fåk F, Buske S, Molin G, et al. A novel probiotic mixture exerts a therapeutic effect on experimental autoimmune encephalomyelitis mediated by IL-10 producing regulatory T cells. PLoS One. 2010; 5(2): e9009. doi: 10.1371/journal.pone.0009009.
4 Berggren A, Lazou Ahrén I, Larsson N, Önning G.. Randomised, double-blind and placebo-controlled study using new probiotic lactobacilli for strengthening the body immune defence against viral infections. Eur J Nutr 2011; 50(3):203-210. doi: 10.1007/s00394-010-0127-6.
5 Costa DJ, Marteau P, Amouyal M, Poulsen LK, Hamelmann E, Czaaubiel M, et al. Efficacy and safety of the probiotic Lactobacillus paracasei LP-33 in allergic rhinitis: a double-blind, randomised, placebo-controlled trial (GA2LEN) study. Eur J Clin Nutr. 2014 May;68(5):602-7. doi: 10.1038/ejcn.2014.13.
6 Peng G-C, Hsu C-H. The efficacy and safety of heat-killed Lactobacillus paracasei for treatment of perennial allergic rhinitis induced by house-dust mite. Pediatr Allergy Immunol. 2005 Aug;16(5):433-438. doi: 10.1111/j.1399-3038.2005.00284.x.
7 Kalliomäki M, Salminen S, Arvilommi H, Kero P, Koskinen P, Isolauri E. Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial. Lancet. 2001;357(9262):1076-9.
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