The microbiome and essential oils are two of my favorite subjects. Learn why bugs are such a hot topic in medicine and the potential of essential oils to positively influence our microbiota.

Every month, I provide you with my “Top Reads.” This summary of some of my favorite noteworthy, interesting, and/or game-changing headlines in natural and integrative health, nutrition, medicine, and science is intended to keep you informed without spending hours sifting through hundreds of sources. Within the next few weeks, I’ll be releasing April’s full list for you to skim or dive-into on a rainy day!

This past week, as I was continuing to add interesting reads to my list, I began sorting through it to start organizing themes. As usual, a large amount of microbiome studies were found at the top of my favorites. A few days ago, I realized I had enough articles on this topic alone to summarize for several blogs! Therefore, I decided that once again the study of how these critter inhabitants are influencing our health deserves another monthly spotlight.

Since the findings of the Human Microbiome Project were revealed, the profound role of the microbiota has been influencing and changing perspectives on the way medicine is being practiced! The effects of our microbiome are so wide-spread that it is uniting all types of practitioners on the concept of integration in medicine. It seems that the more we discover, the more we need to learn. It makes me excited about this “new frontier” of this previously unseen organ to the naked eye.

It boils down to this: “If the bugs aren’t happy, the whole body isn’t!!” Therefore, they need to be considered as part of the resolution for any disease state, symptom, or imbalance. Click here to read why in my post on, “What Happens When We Mess with Our Microbiome?!”

Below, I will discuss how essential oils can be a means to re-balance the bugs in our body and keep our digestive tract healthy. I have found some studies I want to share that show they can do this without causing the unwanted side effects of other microbe inhibitors that can harm the “good guys.”


Essential Oils for Digestive (And Buggy) Health

I’ve written before on how essential oils can balance our digestive health and how probiotics, diet, and lifestyle can keep our microbes happy and our bodies healthy. Now, let’s look at some more information specific to our microbiota below.


Weeding and Feeding Good Buggies

In the past, I’ve discussed that essential oils provide polyphenols which can feed our belly bugs the food they love! (You can read more about this here and here.) Still, sometimes, bugs do go awry and “bad guys” can overpopulate our digestive tract creating unwanted outcomes.

The good news is that essential oils can modulate microbe activity as they protect our tissues. For example, a rodent study demonstrated that ocotea essential oil inhibited inflammatory mediators from microbial byproducts and spared gastric mucosa at the same time.

In regards to our gut health, essential oils can act as antioxidants, preventing the damaging effects of an inflammatory process that could occur from a pathogenic overgrowth. One study from BMC Complementary and Alternative Medicine states the following on different species of basil:

The qualitative and quantitative composition of the three essential oils of three basil cultivars (O. basilicum var. thyrsiflora, O. basilicum var. purpureum and O. x citriodorum), cultivated in Armenia, was quite different: O. basilicum var. purpureum essential oil contained 57.3% methyl-chavicol (estragol); O. basilicum var. thyrsiflora oil had 68.0% linalool, and the main constituents of O. x citriodorum oil were nerol (23.0%) and citral (20.7%). The presence of thyrosinase inhibitory activity is enhances the pharmacological value of these oils. They had also high antioxidant…(microbial activity)… and antioxidant agents, with possible application in food industry, cosmetics or medicine.

In another study with rabbits, it was demonstrated that thyme oil increased antioxidant status and decreased oxidative harm on the small intestine. It also positively influenced intestinal integrity, aka preventing “leaky gut.” Furthermore, there was a tendency “for thyme oil to stimulate the abundance of some microbes beneficial in the rabbit gut.”  The abstract states:

The effects of 0.5 g thyme oil per kg dry matter (DM) of diet on duodenal tissue integrity, antioxidant status, phagocytic activity and selected microbiota in the caecum and faeces of rabbits were studied. Twenty-four rabbits were divided into two groups and were fed a commercial granulated diet for growing rabbits (CD) with access to water ad libitum. The first group was fed the CD, while to the CD of the second group thyme oil was added. Intestinal integrity was tested by measuring the transepithelial electrical resistance (TEER). Thyme oil significantly increased the value of total antioxidant status (TAS) in the blood plasma and glutathione peroxidase (GPx) activity in the liver, and it decreased malondialdehyde (MDA) concentration in the duodenal tissue. Thyme oil resulted in strengthened intestinal integrity, as the essential oil supplementation significantly increased TEER values in the experiment. The faecal microbiota of rabbits was almost completely balanced in both groups, and only a slight decrease was found in the microbial population at day 42 of the trial. In both groups, the bacterial counts were generally lower in the caecum than in the faecal samples. In conclusion, dietary supplementation with 0.5 g/kg DM thyme oil may improve intestinal integrity, and it may have an antioxidant effect. A tendency was also found for thyme oil to stimulate the abundance of some microbes beneficial in the rabbit gut. (Effect of thyme oil on small intestine integrity and antioxidant status, phagocytic activity and gastrointestinal microbiota in rabbits. ( Acta Vet Hung. 2013 Jun;61(2):197-208)

A study in chickens also demonstrated that essential oils and herbs had negligible effects on gut microflora and impacted digestion. The abstract reads:

  1. The effect of the dietary inclusion of 5 culinary herbs or their essential oils on the growth, digestibility and intestinal microflora status in female broiler chicks was assessed. From 7 to 28 d of age, either a basal control diet without supplement was given or one of 10 others, consisting of the basal diet with either 10 g/kg herb (thyme, oregano, marjoram, rosemary or yarrow) or 1 g/kg of essential oil. 2. Body mass (BM) and feed consumption (AFC) were measured on a weekly basis and used to calculate chick performance. Total viable counts of lactic acid bacteria, coliforms, anaerobes and Clostridium perfringens were determined at 25 d. Apparent nutrient digestibilities were calculated from the measured values for gross energy, nitrogen (N), dry matter (DM) and organic matter, and sialic acid concentration was also measured. 3. Generally, dietary thyme oil or yarrow herb inclusion had the most positive effects on chick performance, while oregano herb and yarrow oil were the poorest supplements. Only thyme and yarrow in these diets had a different effect when used as a herb or oil on weight gain and BM. 4. Dietary treatment had no effect on the intestinal microflora populations, apparent metabolisable energy (AME) or the calculated coefficients of digestibility. Sialic acid concentration was greatest in the birds given dietary thyme oil, compared with all other treatments except those birds receiving marjoram oil, rosemary herb and the controls. However, less sialic acid was excreted in those birds given diets with oregano or rosemary oils, or oregano herb, than in the controls. 5. Plant extracts in diets may therefore affect chick performance, gut health and endogenous secretions, although the chemical composition of the extract appears to be important in obtaining the optimal effects. (The effect of herbs and their associated essential oils on performance, dietary digestibility and gut microflora in chickens from 7 to 28 days of age. Br Poult Sci. 2007 Aug;48(4):496-506.)

Here are a few other studies on essential oils and unwanted microbes which highlight their potential for keeping us well and not harming our belly bugs:

One of my favorite studies is one that compared the effects of  essential oil of Origanum vulgare L. (EOO) to antibiotics in patients with metabolic syndrome (MS) with gastrointestinal issues. MS promotes infections due to it being an inflammatory condition. According to the article, “After a 10-day treatment, intestinal side effects were absent, improving the phase angle. (4) The results suggest that EOO may exhibit an antibacterial effect, similar to the antibiotic treatment, without promoting MS-specific dysbiosis, and it also improves the phase angle in patients, which is used as an index of health and cellular function.”


Our Gut Health Starts in Our Mouth: Essential Oils and Our Oral Microbiome

Essential oils can positively affect the bugs in our mouth, which influence our whole body health. You can read more about essential oils for dental health here. I’ve also discussed previously how cinnamon and clove are impressive for keeping our oral microbiome balanced.

I like to place a drop an essential oil on my toothbrush to get the benefits of different oils in my mouth.


Conclusion: Why I love Essential Oils


Can you see why I’m so obsessed with essential oils!? They never seem to let me down on integration with any subject, including my other favorite topic of the microbiome!

Here’s my two sentence summary:

Essential oils literally can support all our organs, the newly discovered ancient one, and all systems from head to toe! They keep us healthy and our critter inhabitants happy!!

Here’s to elated oiling for balanced buggies!


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.)