In Part I, I reviewed the holistic wellness properties of essential oils, how they impact our gut health, and that they have the potential to enhance the beneficial impact of balanced belly bugs! In Part II, I discuss why the microbiome is always in my brain and how essential oils may be linked to “healthy, happy, buggy brains!” I’m predicting this discovery will bring a second research explosion on the microbiome!


How the Microbiome in My Brain “Met Up” with Essential oils

Over the past month, I’ve been excitedly prepping for the free online webinar that myself and two of my team leaders are presenting May 23rd. (You are welcome to join us! You can learn more about it and how to listen-in here.)

During this past week, I began testing my webinar software and was becoming more satisfied with my attempts to befriend this technology. When this task was completed for the day, I happily began the mindless act of e-filing some of most recent essential oils research articles. I enjoy this “end of the day unwind,” because I get a chance to catch up on some of my favorite podcasts and seminars. To my heart’s delight, starting May 8th, I was rewarded with a week to dive deeper into my “second scientific love.” Specifically, I was able to listen to all the daily experts on the Microbiome Medicine Summit 2 that I hadn’t gotten to!

Of course, this “buggy” subject had me captivated. What an array of topics and a refreshing view of how these critters are transforming scientists’ and clinicians’ perspectives on the “human body.” The hunch I had on the awe-inspiring aspect of these bugs playing a role in unifying all of the different specialties in medicine seemed to now be a reality!

To my delight, there were two speakers, researcher and renowned expert, Marco Ruggiero, MD and psychiatrist, John Gray, PhD that had me stop in my tracks and prevented me from succeeding in my multi-tasking. These two men where specifically discussing the microbiome in the brain and how it effects the brain and body too!


Yes, You Have Bugs in YOUR BRAIN!

Most of my colleagues, scientists, and I have become comfortable with the fact that the microbiota in the gut affects brain.  The details that have been uncovered can best be summarized by an article written by Leo Galland, MD in 2014:

The human gut microbiome impacts human brain health in numerous ways: (1) Structural bacterial components such as lipopolysaccharides provide low-grade tonic stimulation of the innate immune system. Excessive stimulation due to bacterial dysbiosis, small intestinal bacterial overgrowth, or increased intestinal permeability may produce systemic and/or central nervous system inflammation. (2) Bacterial proteins may cross-react with human antigens to stimulate dysfunctional responses of the adaptive immune system. (3) Bacterial enzymes may produce neurotoxic metabolites such as D-lactic acid and ammonia. Even beneficial metabolites such as short-chain fatty acids may exert neurotoxicity. (4) Gut microbes can produce hormones and neurotransmitters that are identical to those produced by humans. Bacterial receptors for these hormones influence microbial growth and virulence. (5) Gut bacteria directly stimulate afferent neurons of the enteric nervous system to send signals to the brain via the vagus nerve. Through these varied mechanisms, gut microbes shape the architecture of sleep and stress reactivity of the hypothalamic-pituitary-adrenal axis. They influence memory, mood, and cognition and are clinically and therapeutically relevant to a range of disorders, including alcoholism, chronic fatigue syndrome, fibromyalgia, and restless legs syndrome. Their role in multiple sclerosis and the neurologic manifestations of celiac disease is being studied. Nutritional tools for altering the gut microbiome therapeutically include changes in diet, probiotics, and prebiotics.

The full review gets even more exciting for “microbe nerds” in many aspects. However, after this weekend, the topic of immune stimulation at the intestinal mucosa and its systemic effect got my attention.  Here’s the link- the stimulation of macrophages by belly bugs effects our brain-bug traffic!

Galland states, “Bacterial peptides induce intestinal macrophages and T-cells to produce the cytokines interleukin-1beta (IL-1b) and tumor necrosis factor alpha (TNFa)19; bacterial cell wall lipopolysaccharides (LPS) induce synthesis of IL-18.20


The Microbiome in Our Brain

So, we know that bugs effect our brain and that our belly bugs have far-reaching effects, but the concept of bugs living in our brain is relatively new. This concept, along with the recent discovery of the lymphatic system of the brain, provides further proof of how what we thought we knew about what lies in our skull is becoming obsolete!

It appears we aren’t as sterile as we thought… anywhere!

I remembered a few months back, I read a summary of Dr. Ruggiero’s research on the brain microbiome, the macrophage stimulator discussed above, and how this connected to the mechanism he explained on how we get microbes in our brain:

Microbes basically “piggyback” on these macrophages. The macrophages then transport them to the brain, effectively “hiding them” for safe delivery. Dr. Ruggiero and Dr. Gray both referenced the articles that made this discovery. I explored and found them. Here’s the 2013 study abstract on discovering the brain microbiome in HIV patients:

The brain is assumed to be a sterile organ in the absence of disease although the impact of immune disruption is uncertain in terms of brain microbial diversity or quantity. To investigate microbial diversity and quantity in the brain, the profile of infectious agents was examined in pathologically normal and abnormal brains from persons with HIV/AIDS [HIV] (n?=?12), other disease controls [ODC] (n?=?14) and in cerebral surgical resections for epilepsy [SURG] (n?=?6). Deep sequencing of cerebral white matter-derived RNA from the HIV (n?=?4) and ODC (n?=?4) patients and SURG (n?=?2) groups revealed bacterially-encoded 16 s RNA sequences in all brain specimens with ?-proteobacteria representing over 70% of bacterial sequences while the other 30% of bacterial classes varied widely. Bacterial rRNA was detected in white matter glial cells by in situ hybridization and peptidoglycan immunoreactivity was also localized principally in glia in human brains. Analyses of amplified bacterial 16 s rRNA sequences disclosed that Proteobacteria was the principal bacterial phylum in all human brain samples with similar bacterial rRNA quantities in HIV and ODC groups despite increased host neuroimmune responses in the HIV group. Exogenous viruses including bacteriophage and human herpes viruses-4, -5 and -6 were detected variably in autopsied brains from both clinical groups. Brains from SIV- and SHIV-infected macaques displayed a profile of bacterial phyla also dominated by Proteobacteria but bacterial sequences were not detected in experimentally FIV-infected cat or RAG1?/? mouse brains. Intracerebral implantation of human brain homogenates into RAG1?/? mice revealed a preponderance of ?-proteobacteria 16 s RNA sequences in the brains of recipient mice at 7 weeks post-implantation, which was abrogated by prior heat-treatment of the brain homogenate. Thus, ?-proteobacteria represented the major bacterial component of the primate brain’s microbiome regardless of underlying immune status, which could be transferred into naïve hosts leading to microbial persistence in the brain.

I also found a small study with multiple sclerosis patients that verified these findings.

Both articles are pretty complex, and I will be compiling more articles and researching this more over the next few months. Or, years?

I’ve listed them both below if you want to learn more now.


How Does the Brain Microbiome Relate to Essential Oils?

Here’s the rabbit hole I’m diving down on this connection. Okay, it’s more of a skip down the winding path, as I’m not there yet, but I’m making my way. Here’s my current thought pattern:

Essential oils modulate inflammation and immune signaling pathways, so could they stimulate macrophages and potentially modulate buggy piggyback to our brain?


I did find a few hits on this. One study explored this immune activation with eucalyptus oil in vitro and in vivo. The essential oils stimulated macrophages differentially from infectious mechanisms. This is good, because it could mean that essential oils will stimulate the piggybacking only with healthy critters!!



Okay, I’m going to stop here, but will continue with this topic in the future. I believe this could potentially be a very exciting research topic!! Stay tuned.




Raphael Kellman, MD with Marco Ruggiero MD, PhD (Interview). The Study of Brain Microbiota and Health. Microbiome Medicine Summit 2. May 13, 2017.

Raphael Kellman, MD with John Gray, PhD (Interview). Healthy Microbiome and Personal Relationships. Microbiome Medicine Summit 2. May 14, 2017.

(Note: I do not have an affiliation with the summit.)

Galland L. The Gut Microbiome and the Brain. Journal of Medicinal Food. 2014;17(12):1261-1272. doi:10.1089/jmf.2014.7000.

Mayer EA, Knight R, Mazmanian SK, Cryan JF, Tillisch K. Gut Microbes and the Brain: Paradigm Shift in Neuroscience. The Journal of Neuroscience. 2014;34(46):15490-15496. doi:10.1523/JNEUROSCI.3299-14.2014.

Serafino A, Vallebona PS, Andreola F, et al. Stimulatory effect of Eucalyptus essential oil on innate cell-mediated immune response. BMC Immunology. 2008;9:17. doi:10.1186/1471-2172-9-17.

Branton WG, Ellestad KK, Maingat F, Wheatley BM, Rud E, Warren RL, et al. Brain Microbial Populations in HIV/AIDS: ?-Proteobacteria Predominate Independent of Host Immune Status. PLoS ONE. 2013; 8(1): e54673.

Branton WG, Lu JQ, Surrette MG, et al. Brain microbiota disruption within inflammatory demyelinating lesions in multiple sclerosis. Scientific Reports. 2016; 6: 37344. doi:10.1038/srep37344


Disclaimer: This information is applicable ONLY for therapeutic quality essential oils. This information DOES NOT apply to essential oils that have not been tested for purity and standardized constituents. There is no quality control in the United States, and oils labeled as “100% pure” need only to contain 5% of the actual oil. The rest of the bottle can be filled with fillers and sometimes toxic ingredients that can irritate the skin. The studies are not based solely on a specific brand of an essential oil, unless stated. Please read the full study for more information.

This material is for information purposes only and is not intended to diagnose, treat, or prescribe for any illness. You should check with your doctor regarding implementing any new strategies into your wellness regime. These statements have not been evaluated by the FDA. (Affiliation link.)