We know that the gut and the brain are connected but it is unclear on how they communicate with each other. So far we believe that they communicate in a bidirectional way through the vagus nerve and that your amazing gut bugs use this pathway to nurture, or sometimes, accidentally give the brain a hard time.
When your gut is upset it is often linked to inflammation which can be from things like stress, overindulging, illness, infection, or just not looking after yourself. If you get very stressed, your body produces chemicals that will increase inflammation and alter the way your gut microbiota work. When your gut is inflamed that can also make the cells of your intestine less stable. If this happens, these chemicals (and bacteria and other molecules) may escape from your intestines into the bloodstream.
An increase of these chemicals is thought to cause responses like a foggy mind, sickness, abnormal sleep patterns and fatigue as they have made their way to your brain. There is a barrier around the brain called the Blood-Brain Barrier (BBB) but if they can get through this barrier they may cause neuroinflammation or inflammation in the brain. The take-home message here is to stay calm this Xmas and don’t overindulge too much. Let someone else look after everything and put your feet up.
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Valkanova, V., Ebmeier, K. P., & Allan, C. L. (2013). CRP, IL-6 and depression: a systematic review and meta-analysis of longitudinal studies. Journal of affective disorders, 150(3), 736-744. doi:10.1016/j.jad.2013.06.004
Walker, F. R., Nilsson, M., & Jones, K. (2013). Acute and chronic stress-induced disturbances of microglial plasticity, phenotype and function. Current drug targets, 14(11), 1262-1276. doi:10.2174/13894501113149990208