Page 1, 2, 3
Essential Oils Impact on Intestinal Microbes In Vitro
An in vitro study with eight essential oils, the authors sought to determine if essential oils selectively inhibited several microbes that cause intestinal dysbiosis while sparing 12 species of intestinal bacteria. The authors reported:157
The most promising essential oils for the treatment of intestinal dysbiosis are Carum carvi, Lavandula angustifolia, Trachyspermum copticum, and Citrus aurantium var. amara. The herbs from which these oils are derived have long been used in the treatment of gastrointestinal symptoms and the in vitro results of this study suggest that their ingestion will have little detrimental impact on beneficial members of the GIT microflora. More research is needed, however, to investigate tolerability and safety concerns, and verify the selective action of these agents.157
In a study with swine cecal digesta, the authors tested the antimicrobial effects of 66 essential oils and their impact on swine gut. The authors stated:
The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Among 66 essential oils/compounds that exhibited ≥80% inhibition towards Salmonellatyphimurium DT104 and Escherichia coli O157:H7, nine were further studied. Most of the oils/compounds demonstrated high efficacy against S. typhimurium DT104, E. coli O157:H7, and E. coli with K88 pili with little inhibition towards lactobacilli and bifidobacteria. They were also tolerant to the low pH. When mixed with pig cecal digesta, these oils/compounds retained their efficacy against E. coli O157:H7. In addition, they significantly inhibited E. coli and coliform bacteria in the digesta, but had little effect on the total number of lactobacilli and anaerobic bacteria.158
Essential Oils Impact on Intestinal Flora In Vivo
In a 2010 in vivo study, it was demonstrated that ocotea essential oil inhibited inflammatory mediators from microbial byproducts while simultaneously protecting the gastric mucosa of rodents.159
In another study with rabbits, thyme oil increased antioxidant status (i.e., GPx activity) and decreased oxidative harm (i.e., lowered malondialdehyde) in the small intestine. It also positively influenced intestinal integrity, aka preventing "leaky gut," as measured by transepithelial electrical resistance (TEER). Furthermore, there was a tendency "for thyme oil to stimulate the abundance of some microbes beneficial in the rabbit gut." The abstract states :160
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.160
A study in chickens demonstrated that five culinary herbs and their essential oils (thyme, oregano, marjoram, rosemary, and yarrow) had negligible effects on gut microflora and beneficially impacted these broiler chicks' digestion. In the experiment, body mass and feed consumption were measured on a weekly basis. Counts of lactic acid bacteria, coliforms, anaerobes, and Clostridum perfingens were assessed at 25 days. Finally, digestibilities were measured via nitrogen (N), dry matter (DM) and organic matter, and sialic acid concentration. The researchers concluded:161
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.161
My Clinical Experience: How I Use Essential Oils Internally for Intestinal Discomfort
I find oral administration of essential oils the most effective method of application for clients that are seeking relief from symptoms of irritable bowel syndrome, functional gastrointestinal disorders, bloating and abdominal extension, food poisoning (due to antimicrobial effects noted above), discomfort, gas, dysbiosis, and changes in stool frequency.
I instruct my clients to administer one to two drops of the selected essential oil from a quality supplier. The drops are placed in a vegetable capsule (enteric coated) using pipette droppers. Next, they are asked to fill the remainder of the cap with coconut oil or a non-dairy milk substitute. This is important for sensitive patients, as it will provide coating for the stomach.
Essential oils are alternated every two months or until symptoms have resolved and lab markers are back within normal ranges. I also recommend that my clients take 1-2 days off per week depending on tolerance. If one experiences burping, GI discomfort, or notices loose stools, I will decrease the dose.
I often supplement any gut protocol with a relaxing essential oil to restore the nervous system. The most well-known and most researched essential oil for this is lavender.162-167
Lavender has a good reputation for alleviating anxiety Europe. Germany has authorized a preparation of lavender oil, Silexan, for treatment of restlessness during anxious mood.162-167 It is branded as LASEA and is standardized for 20-45% linalool and 25-46% linalyl acetate.162 Two trials have indicated that Silexan has been effective in mood related issues without unwanted sedative effects.165,166 According to Examine, "It is prescribed (or at least used) for Generalized Anxiety disorder in Germany without apparent benzodiazepene actions."163
In a comprehensive review, the nervous system effects of lavender were analyzed in animal and human clinical trials. The authors reported that lavender was shown to have in vivo effects of modulating inflammatory pathways in the brain and on the neurotransmitters dopamine, GABA and serotonin. Human studies with functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) also indicated brain imaging evidence for relaxation effects. These calming effects were also shown to have an impact on sleep, pain, and positive mood.167
These psychoneurological effects will impact gastro-intestinal function related to the gut-brain connection, stress, and resultant discomfort and pain.168
As far as dosage, both Examineand the American Botanical Council's Herbal Expanded Commission E Commissions report that the internal dosage of lavender oil is between 80-160 mg of essential oil.162,163 Using the conversions in the table:
- 30 mg = approximately 1 drop of oil
- 80-160 mg would be approximately 3-6 drops of lavender oil
I have often also used this oil internally at these dosages for clients who appear to have hyperactive sympathetic activity, which is most of my IBS and pain clients.
Conclusion: Summarizing the Art and Science of Selecting the "Correct" Essential Oil
Essential oils can effectively remove the obstacles in the way of healing via their multimodal effects while simultaneously and synergistically working with the body to bring it to balance. This is due to their biochemical constituents affecting physiology combined with the instantaneous psychological effect of their aroma.1-2
Not only are essential oils synergistic within themselves and with other modalities, they are also the same regarding their action with the human body. One human study provided evidence that the metabolomics and biochemical pathways of individuals were modulated differently by the same essential oil intervention.
In the clinical trial, researchers sought to determine the metabolic changes in thirty-one females with mild anxiety symptoms after exposure to aroma inhalation for 10 days. In several participants, no effect was found in the measurements studied, yet there were minimal disturbances and many benefits reported by all the responsive subjects. This demonstrates the mechanisms of essential oils "innate wisdom" to bring about balance to the human body. The authors concluded:169
A significant alteration of metabolic profile in subjects responsive to essential oil was found, which is characterized by the increased levels of arginine, homocysteine, and betaine, as well as decreased levels of alcohols, carbohydrates, and organic acids in urine. Notably, the metabolites from tricarboxylic acid (TCA) cycle and gut microbial metabolism were significantly altered. This study demonstrates that the metabolomics approach can capture the subtle metabolic changes resulting from exposure to essential oils, which may lead to an improved mechanistic understanding of aromatherapy.169
I have now provided evidence that essential oils can address underlying causes of dysfunction while simultaneously alleviating contributors, triggers, and mediators. I have shown this through the example of using them internally for intestinal discomfort. By reviewing what I have learned and my clinical experience for the past seventeen years, my hope is that now clinicians can decipher how to proceed with more informed, safe, and confident decisions on dosage and proper use of this powerful, ancient, innately intelligent, healing modality.
Page 1, 2, 3
References (for Parts 1 and 2, .pdf) were not in our print edition.
Sarah LoBisco, ND, is a graduate of the University of Bridgeport's College of Naturopathic Medicine (UBCNM). She is licensed in Vermont as a naturopathic doctor and holds a bachelor of psychology degree from State University of New York at Geneseo. Dr. LoBisco is a speaker on integrative health, has several publications, and has earned her certification in functional medicine. Dr. LoBisco currently incorporates her training as a naturopathic doctor and functional medicine practitioner through writing, researching, private practice, and her independent contracting work for companies regarding supplements, nutraceuticals, essential oils, and medical foods. Dr. LoBisco also enjoys continuing to educate and empower her readers through her blogs and social media. Her recent blog can be found at www.dr-lobisco.com.