We all carry around millions of friends, bacteria, viruses, and yeasts; parasites, working together in perfect harmony to aid digestion, defensive protection, nutrient absorption, enzyme activity, and no doubt, dozens of yet unknown symbiotic relationships that keep us alive. We call these ‘colonies’ of friends flora. Though they aid in our immune responses, it is the role of our immune system to keep proper balance so there doesn’t rise up a revolution. Again, it’s all about balance. Should one colony reproduce more rapidly than an opposing colony – we have a rebellion needing to be squashed by an immune response. Balance.

This internal balance is matched by the external balance. We are at one with both environments. Night, and more specifically sleep – deep sleep, is our greatest ally in keeping our internal environment in balance. Every morning (assuming the victory occurred in the previous hours) your immune system’s internal balance has ‘set’ the day’s picture: from your ability to fight disease, get pregnant, have balanced thought and memory, maintain metabolic homeostasis, and ‘win’. We were created to live in community, not just with other humans but with other living organisms in the microcosm we call our body.

We feed these little fellows all day long. During the day, light energy strikes our skin and is carried by cryptochromes to our symbiotic partners, food is processed in our belly and shared with them, and they feed off our blood, oxygen, sugar, hormones, and dying cells. Reproductive adults feed them with sex hormones and make them grow big and strong. We’ll see that this is both a blessing and a curse, as it gives us a stronger immune system in our reproductive years (blessing), but it creates a more destructive response in those with autoimmune disorders (curse).

All day long our flora flourish; they are opportunistic organisms that take advantage of the environment and reproduce as rapidly as possible. As they do, they exude waste called endotoxins that buildup along the course of the day. If overgrowth (rebellion up- rises) happens, your immune system flexes its muscle to keep the peace. Night and sleep are important components of this balance-keeping. As a matter of fact, the buildup of these ‘endotoxin wastes’ help stimulate a melatonin release by our pineal gland that enables us to go to sleep. Let me give you an example of the mechanism:

During the day, my normal concentration of flora grows, reproduces, and strives to take over its host (me). As it does, it produces cellular wastes and byproducts of metabolism that increase in concentration in my intestinal and other bodily lumens. The increase concentration of endotoxin as well as a decrease in cortisol production from my adrenal glands (a function of balance from brain signals in the hippocampus) as the day progresses causes me to release melatonin that enables me to calm my brain (alpha wave production) and fall asleep. During sleep (stage 3, 4, and REM) my brain signals the release of Growth hormone which stimulates different chemicals called cytokines like interleukin-2 (a Th1 response) to kill-off the daily rise in flora and ‘thin the herd’.

Raising a garden of bacteria is like growing carrots. The garden can never be healthy if thousands of different seeds were simply cast into the soil without proper order, culling, tending, weeding, nourishment and care. Light and dark play a huge role in this matter.

The success of my reaching stages of sleep necessary for correct hormone release to maintain balance depends on light and dark cycles. Light hitting my eyes and skin activate specific neurons that tell my body what time it is and signal bacteria to feed, which hormones I release, and how I am to survive. Homeostasis is really my body’s attempt to thrive. Deep parts of my brain run on autopilot – Where’s food? Where’s air? Is it hot? Is it cold? Where’s danger? Where’s a mate?

Darkness is our friend. It is through these necessary dark cycles each day that enable hormone release. Just as light signals food gathering, action and reproduction, dark is equally important. God created the day and night and they were both “good”. Darkness stimulates melatonin release necessary for sleep. The deeper stage of sleep are necessary for balance of my immune system; the balance of my internal ‘friends’ is an absolute in maintaining gut health; the gut controls inflammatory responses in the body and brain, and the brain controls the rhythm of hormone and neurotransmitter release to keep us sane, productive, joyful members of society.