If you have been following my conversations here in the blog, you already know that the microbiome plays a critical role in virtually all aspects of health, both mental and physical. The microbiome determines whether or not you are depressed or happy, have psoriasis or not, develop diverticulitis or colon cancer or not. And, not surprisingly, the gastrointestinal (GI) microbiome plays a prominent role in sleep.

I first came to appreciate the role of the microbiome on sleep when I unexpectedly experienced profound deep sleep when I consumed the Lactobacillus reuteri yogurt. Recall that, in order to boost the number of microbes beyond the relatively low quantity provided by the Gastrus tablets that serve as the starter (since these tablets are intended for consumption by infants to reduce colic and regurgitation of breastmilk or formula), we use my method of prolonged fermentation to allow a minimum of 12 doublings of the microbe and adding prebiotic fiber as “fertilizer” to ensure high bacterial counts. Our flow cytometry efforts yielded counts of 250-300 billion microbes per 1/2-cup serving. As a chronic insomniac, always struggling to fall asleep, plagued by frequent awakenings at the slightest disturbance, early awakening, etc., I was pleasantly surprised to find myself sleeping 9 hours straight-through, nights filled with vivid childlike dreams. (Not everyone experiences these effects, by the way, a phenomenon likely due to a different background microbiome context. Emerging evidence suggests that species such as Akkermansia and Ruminococcus may need to be present for full effects to be experienced, a conversation for another time.) People who wear various actigraphic devices (e.g., Apple Watch, Oura ring, Fitbit, Whoop, etc.) that (indirectly) quantify the duration of REM sleep report lengthening of this restorative phase of sleep. This sleep effect, by the way, has never been previously reported in any scientific study. For me, personally, the restoration of L. reuteri has been life-changing, freeing me from chronic sleep deprivation to enjoying night after night of undisturbed, deep sleep.

I learned another sleep lesson by cultivating the commercial microbe Lactobacillus casei Shirota that I have previously discussed for its important immune system-boosting effects, reducing the likelihood of acquiring upper respiratory viral illnesses by 50% and, should you still develop a viral infection, abbreviates the duration by 50%, phenomena demonstrated in three human clinical studies. The microbe is sold as a low-fat sugary product (that those of us around here would regard as a garbage product) so, once again, I applied my method of prolonged fermentation with the addition of prebiotic fiber to make a rich, thick yogurt. (The successive fermentations mean that the garbage ingredients are long gone.) I added consumption of L. casei yogurt to consumption of L. reuteri yogurt and, lo and behold, I was sleeping an astonishing 12 hours a night, often awakening and thinking “Maybe I’ll sleep a little more”—an effect so powerful that I had to stop the L. casei yogurt. Others (but not everyone) in my Inner Circle reported similar effects, obtaining profound sleep with the combination.

Why would these microbial species yield deep sleep? No one has formally explored these questions. If many of the benefits of L. reuteri are mediated via a boost in oxytocin, could this be yet another effect from higher oxytocin levels? We don’t yet know.

Another interesting experience: Martha Carlin and microbiologist Raul Cano, PhD, of BiotiQuest formulated a probiotic product called Simple Slumber. Once again, a number of members in my Inner Circle reported that, yes, they experienced deep sleep with this product. I asked Martha and Raul what the basis was for the formulation and they told me that they based it on observations that this collection of species/strains “collaborate” in producing melatonin—not stimulating the pineal gland to produce melatonin, but produce melatonin in the GI tract. While the beneficial effect on sleep is really interesting, there may be benefits beyond sleep, as preliminary evidence suggests that sleep deprivation not only reduces melatonin levels but also increases intestinal permeability and thereby endotoxemia while also reducing populations of the very important gut microbes Akkermansia and Faecalibacterium, among the most important of all gut microbes. The boost in melatonin combined with improved sleep therefore can be expected to exert some important health benefits. Interestingly, the quantity of melatonin produced by gut microbes is 400-times greater than the quantity produced by the pineal gland. The boost in melatonin may therefore yield other benefits such as lower blood pressure (especially during sleep), preservation of bone density, heightened immune responses, even reduction in risk for breast cancer. Intestinal melatonin is proving to be an important modulator of the intestinal barrier. (Please don’t interpret these comments to mean that you should supplement melatonin; interpret these comments to mean that we need to take steps to cultivate the microbes that produce melatonin within the GI tract.)

It is also becoming clear that the GI tract participates in the circadian cycle, i.e., the 24-hour light/dark cycle that all earth’s creatures follow and that GI microbes play a role in, as well. Insights into microbial contributions to sleep and circadian rhythm are completely changing our views of these phenomena in ways that will further empower our ability to obtain quality restful, deep sleep without reliance on such things as pharmaceuticals.

Some unanswered questions remain about the role of the microbiome in sleep that we and others will hopefully answer in future. Among them:

  • Do other Lactobacillus species share this sleep-enhancing effect?
  • How much of the sleep effect is due to melatonin, how much to oxytocin, or are there additional mechanisms at work?
  • Are there “collaborative” effects with other microbes that could enhance the effect or increase the effect in non-responders?
  • What role does SIBO, dysbiosis, and endotoxemia play? Does SIBO, for instance, block some of the beneficial effects? (I believe it does.)
  • If prolongation of the REM period of sleep is indeed confirmed by EEG (not actigraphy), does this mean that the emotional processing and memory consolidation that occurs during REM will be amplified? Could this become a tool for better dealing with, for instance, emotional trauma or loss?

Stay tuned. We are learning new lessons about sleep at breakneck speed.