Our bodies play host to trillions of bacteria. But, contrary to popular belief, they’re not harming us - they’re helping us! In fact, we are piloted by our microbiome which outnumbers our bodies’ cells 10 to 1.
Furthermore, our gastrointestinal tract has its own nervous system: the enteric nervous system.
The enteric nervous system has 200 million neurons and is able to make decisions in the body without first talking to the brain! It communicates directly with both the central nervous system and autonomic nervous system. These connections influence our thoughts, cognitive function, and behavior.
It stands to reason that a healthy gut affects our day-to-day decisions - from the foods we choose to decisions we make on impulse.
Our immune system is another one of those complex systems. The central nervous system influences the activity of the immune system. The immune system modulates brain activity, including body temperature, sleep and feeding behavior.
In the case of injury or sickness, research shows that the central nervous system uses adrenal hormones as part of an indirect path of communication, which results in the rapid breakdown of many immune cells (1).
Since all these systems are so intricately connected, the health of one is dependent on the health of the next to function at its best.
The gut microbiome is rife with bacterial denizens who assist us in digesting our food. It's becoming increasingly clear that they have a huge impact on not just our overall metabolism but on our immune system as well.
Think of it this way: Over thousands of years of evolution humans (and other animals) have developed a symbiotic relationship with bacteria that help rather than hurt us.
Moreover, it only makes sense that part of their help comes in assisting us in fighting off other organisms (pathogenic bacteria, viruses, protozoa, and so on) that would otherwise do us harm. It is to their benefit to do so as well!
Make no mistake, friendly bacteria such as Bifidobacterium and Lactobacillus do not participate in our bodies’ defense against invading pathogens just because they are generous or kind little critters. Rather, it is simple evolutionary self-interest.
We play host to these bacteria, and they lead a comfortable, unseen life in our guts, reproducing and moving on when their time comes. But if they let some other bacterium or virus invade and overcome us, they lose their host, which means they too, die.
Clearly, the first line of defense against any viral or bacterial infection is the body’s own immune system, but it can’t do all the work on its own.
It needs good nutrition, including proper doses of vitamins and essential elements, a good night’s sleep, exercise – and a healthy gut microbiome.
Human beings are pattern-oriented creatures. Because of this, we do better with replacement than restriction. Rather than worrying about what we can’t eat to ensure good health, it’s a lot more fun to focus on what we should eat!
Taking a regular probiotic supplement not only helps your digestion and enables you to manage your weight more effectively. It also helps ensure that your gut can do its part in protecting you from those invaders we can’t see that seek to do us harm.
Science daily: An interconnection between the nervous and immune system
Neuroendocrine reflex triggers infections September 19, 2017
Cellular immune surveillance of central nervous system bypasses blood-brain barrier and blood-cerebrospinal-fluid barrier: revealed with the New Marburg cerebrospinal-fluid model in healthy humans.
Kleine TO.Cytometry A. 2015 Mar;87(3):227-43. doi: 10.1002/cyto.a.22589. Epub 2015 Jan 29.PMID: 25641944
The blood-central nervous system barriers actively control immune cell entry into the central nervous system.
Engelhardt B.Curr Pharm Des. 2008;14(16):1555-65. doi: 10.2174/138161208784705432.PMID: 18673197
Published: 26 May 2004
Elaborate interactions between the immune and nervous systems
Nature Immunology volume 5, pages 575–581(2004)