Posted by Tayler Albanese - (LinkedBiotics Research Team) on 4th Aug 2016
Isn't it awful how much you're affected when you don't get a good night's sleep? Insomnia, a disorder in which a person struggles to fall or stay asleep, affects one-third of Americans. Lack of sleep can decrease productivity, increase blood pressure and even give rise to symptoms of depression. Who would want any of that?! So what causes the sleep struggle? Great question. This next part may be overwhelming, but bear with me, I'll break it down. Two main causes of insomnia: a deficiency in neurotransmitters, a chemical messenger that tells your body to do something, and an increase in the hormone cortisol. I'll explain the first cause now: sleep is mainly regulated by the hormone melatonin. Melatonin is produced from the neurotransmitter serotonin, so anything that affects serotonin will ultimately affect melatonin and everything it's implicated in, such as sleep. Basically, no serotonin = no melatonin = no sleep. Of course, many more factors contribute to the quality of someone's sleep, such as cortisol levels as aforementioned. Now I'll explain how that plays a role. According to the article "Get Better Sleep: The Truth Behind Your Insomnia," cortisol can create large disturbances in a person's sleep cycle if it isn't properly balanced. When your body is under stress, many factors change such as blood sugar level, blood pressure, metabolism and immune response. Cortisol tries to regulate these levels. So when cortisol cannot be produced effectively, your body cannot maintain all the affected factors. This is exactly why you have difficulty sleeping when under a lot of stress.
How do we ensure serotonin is being produced so we can get our well-deserved beauty sleep? You'll soon find out. Interestingly, the digestive tract actually produces 90% of the body's serotonin, this makes it easy for serotonin, and everything it affects, to be modified if the gut has any complications. The gastrointestinal tract has a close relationship with immune cells. The website Gut Critters explains how an enzyme in the liver called indoleamine dioxygenase (IDO) suppresses T-cells, important cells that help fight off foreign substances invading a person's body. This causes an increase in cortisol and a decrease in serotonin because it attacks tryptophan, the amino acid responsible for producing serotonin. That gives us an answer for ensuring serotonin production: it's important to keep your digestive tract happy and healthy!
So how do we have a healthy gut? Gut flora is composed of the microorganisms that live within the digestive tract and help your body. Sleep can be negatively impacted if the gut flora is disturbed. Fortunately, Probiotics may help people get the sleep they deserve by utilizing these connections. Believe it or not, most bacteria is beneficial! When ingested, either through strain-specific supplements or fermented foods, the gut flora can be replenished. A domino-effect is then initiated: the gastrointestinal tract is able to function properly and relay information to the immune system appropriately. Because these systems are able to work normally, they can regulate cortisol and serotonin levels as needed and the chances of having a peaceful night should increase. Hallelujah! It's amazing how all these systems are connected.
Then how do Probiotics have an effect? Well, Dr. David Perlmutter describes Lactobacillus plantarum as being, "the one probiotic supplement you need to be taking" due to its effectiveness. This bacteria helps maintain the permeability of the gut, in other words, how easy or difficult it is to let substances through the intestinal lining. It creates a stronger guard, making the lining more selective about what enters the tract. Which is good, you don't want some Joe Shmoe entering your digestive tract, now do you? If the digestive system is optimally functioning (go Probiotics!), everything it impacts can therefore work properly too, including regulating neurotransmitters and hormones that perform to maintain a beneficial sleep cycle. A healthy gut yields serotonin, producing melatonin, leading to more sleep. Although there is not a copious amount of solidified evidence showing sleep improvements from ingesting probiotics, it is a promising idea that is being further researched and no substantial negative impacts have been founded.