Our immune system is a fabulous system. Over the millions of years of our evolution from a single-celled living species to Homo sapiens, the complexity of this system and thus its extensive capabilities have greatly increased. To grasp this complexity, the immune system is described in two parts: innate immunity and acquired immunity. It is not the intention here to discuss the immune system in its entirety, but it is important to briefly touch on the innate immune system. A very important part of this system is formed by barriers such as the skin and mucous membranes. These form the boundary between our internal environment or "inner world" and the outside world which is full of stress, pathogens and toxins (food, environment and medication). Having these barriers intact and having the right humane bacteria protecting and maintaining these barriers are primordial to having a properly functioning immune system. The most important barrier system is formed by our intestines and in healthy individuals consists of an intact row of intestinal wall cells, a thick layer of mucus and the right intestinal bacteria. Chronic gut problems are therefore always going to have negative effects on our immune system and on our health. Hippocrates knew it already 400 years BC: "all diseases begin in the gut". More and more scientific evidence is appearing that healthy gut and in particular healthy gut flora is important to lower the risk of cardiovascular disease, neurological disorders, autoimmunity, allergy etc.... Secondly, the gut and our digestive system is also extremely important to absorb the right nutrients (vitamins, minerals, amino acids, etc.) so that we not only have the right building blocks to keep our body physically in order, but also to be able to make the right substances (enzymes, hormones, neurotransmitters, etc.) to keep our body metabolic, hormonal, immunological and neurological in the best condition. It is therefore obvious that a healthy diet with sufficient diversity and nutrients is one of the basic conditions for our health. And thirdly, the gut is a great detoxification organ that directs the waste out of the body. Constipation, for example, can be very detrimental to the health of the gut and thus the overall health.
Stress, of course, can harm intestinal health. Not only does the activation of our stress axis (HPA-axis) and adrenergic hormones reduce the energy supply to the digestive organ, but they also change the composition of the intestinal microbiome and reduce the integrity of the intestinal wall ("leaky gut"), which increases inflammation and further undermines the function of the barrier. However, it must also be said that "too little stress" can also trigger this: sitting on your butt all day without sitting breaks, eating too much and/or too frequently, not enough challenge, are all situations that are pathogenic for us humans. So "going the easy way" is not good advice either. Giving your body just that little bit of stress now and then keeps us healthy!
Drinking water is important, that goes without saying. But as also explained in our blog in October 2020 about drinking, you can also unbalance your water-skin balance by drinking too frequently and too much.
Ne quid nimis: nothing too much, everything in moderation. That also applies to your immune system.
Gut microbiota: Role in pathogen colonization, immune responses, and inflammatory disease.
Pickard JM, Zeng MY, Caruso R, Núñez G.Immunol Rev. 2017 Sep;279(1):70-89. doi:10.1111/imr.12567
The Microbiota-Gut-Brain Axis.
Cryan JF, O'Riordan KJ, Cowan CSM, et al. Physiol Rev. 2019 Oct 1;99(4):1877-2013. doi: 10.1152/physrev.00018. 2018.
Gut Microbiota and Immune System Interactions.
Yoo JY, Groer M, Dutra SVO, Sarkar A, McSkimming DI.Microorganisms. 2020 Oct 15;8(10):1587. doi: 10.3390/microorganisms 8101587
Interaction between the gut microbiome and mucosal immune system.
Shi N, Li N, Duan X, Niu H.Mil Med Res. 2017 Apr 27;4:14. doi: 10.1186/s40779-017-01229. eCollection 2017.
Role of intestinal microbiota and metabolites on gut homeostasis and human diseases.
Lin L, Zhang J.BMC Immunol. 2017 Jan 6;18(1):2. doi: 10.1186/s12865-016-0187-3