Monolaurin and Digestion – Lessons from Animal Studies

Last Updated: February 22, 2019 | First Published: February 18, 2019
Reviewed by: Dr. Jennifer Meza, M.D.

What animal studies may suggest about Monolaurin’s effect on digestive bacteria (archaea).

Monolaurin and Digestion

Lessons from Animal Studies


Farm animals may have digestive complications not unlike some people. Veterinarians, doctors, and pharmacists alike are continuously looking for remedies which don’t cause unwanted side effects like antibiotic resistance, destroying of “good” gut bacteria, etc.

In this article, we explore two types of bacteria which effect farm animals and monolaurin’s potential part to play in supporting a healthier life of these animals.

Archaebacteria specifically, ruminal methanogens (bacteria in farm animals which cause greenhouse gas methane)

Archaebacteria (sometimes referred to as archaea) are a diverse group of bacteria which are separated into three major groups: methanogens, halophiles, and thermophiles. The methanogens are anaerobic bacteria that produce methane and are found in sewage treatment plants, bogs, and the intestinal tracts of ruminants. [1] In farm animals, these bacteria case the bi-product of methane which is a problem for two reasons: methane is a greenhouse gas which contributes to climate change, and methane produced in the rumen (a special area of the digestive system which breaks down animal feed and plant matter) causes a loss of up to 12% of the animal’s energy derived from its food [2]. Methane produced from livestock accounts for 50% of all the greenhouse gas methane produced from human activity. [3]

Farmers and scientists searching for a way to lower the methane produced by farm animals have looked to reduce and eliminate this bacterium from the digestive tract of farm animals.

In one study, Monolaurin was able to eliminate Fibrobacter succinogenes and Methanomicrobiales below detectable limits. Total Archaea were decreased by up to over 90% [4]

“Monolaurin completely inhibited Fibrobacter succinogenes in all diets while the response of the other cellulolytic bacteria varied in dependence of the diet… total Archaea were decreased by up to over 90% … monolaurin exerted variable effects mediated by unknown mechanisms on important ruminal microbes involved in carbohydrate degradation, along with its suppression of methane formation.” [4]

In another study, monolaurin was shown to inhibit methanogenesis, increase cell membrane permeability, and decrease survival of M. ruminantium.[3]

“C12 (Lauric Acid) and C14 (myristic acid) had the strongest effect on cell viability, as 57% and 64% of the cells were categorized as dead after 3 h, while in the C16 (palmitic acid) group only 32% of cells were dead or, as part of the cells were not red but yellow, damaged. At 24 h, nearly all cells treated with C12 and C14 were dead, compared to 60% of dead cells found in the control. “ [3]

Archaea may potentially be pathogenic in humans [10], and these results show that monolaurin may be an effective option for eliminating harmful and unwanted gut bacteria including Archaebacteria without adverse side effects.

Enterococcus faecalis (a type of bacteria typically present in the digestive tract, but can spread and cause disease in other parts of the body)

Enterococcus faecalis is a Gram-positive, commensal bacterium which is found in the gastrointestinal tracts of humans and other mammals. Enterococci of animal origin can cause infections in humans and be quite dangerous for those with bloodstream infections and in hospital environments. [5]

Infections commonly caused by enterococci include urinary tract infection (UTIs), endocarditis, bacteremia, catheter-related infections, wound infections, and intra-abdominal and pelvic infections. Many infecting strains originate from the patient's intestinal flora. From here, they can spread and cause UTI, intra-abdominal infection, and surgical wound infection. Enterococci are surprisingly resistant to many pharmaceuticals including penicillin, making them increasingly difficult to treat. [7]

One study showed that Monolaurin and Lauric Acid were effective in disrupting Enterococcus faecalis and associated biofilms:

“Both Glycerol Monolaurate (monolaurin) and lauric acid were effective in inhibiting biofilm development as measured by decreased numbers of viable biofilm-associated bacteria as well as decreased biofilm biomass. Compared with lauric acid on a molar basis, GML represented a more effective inhibitor of biofilms formed by either S. aureus or E. faecalis.” [8]

Another study goes on to demonstrate that monolaurin may be able to suppress the growth of antibiotic-resistant E. faecalis in the lab:

"We found that Glycerol Monolaurate (GML) suppresses growth of vancomycin-resistant Enterococcus faecalis on plates with vancomycin and blocks the induction of vancomycin resistance, which involves a membrane-associated signal transduction mechanism, either at or before initiation of transcription. Given the surfactant nature of GML and the results of previous experiments, we suggest that GML blocks signal transduction." [11]

The ability of monolaurin to stop the growth of Enterococcus faecalis, even strains which are resistant to antibiotics, is promising for those who may suffer from an infection from this bacteria.

Other studies on ruminal methanogenesis

A study in the UK used monolaurin to suppress methanogenesis in cows using a mixture of lauric (C12) and myristic acids (C14). [6] The study indicates that monolaurin might help curb the production of methane, a greenhouse gas, in farm animals by destroying the source bacteria in their gut.

“The present study demonstrated a clear synergistic effect of mixtures of C12 and C14 in suppressing methanogenesis, mediated probably by direct inhibitory effects of the fatty acids on the methanogens.” [6]

A study in Belgium showed that the use of coconut oil, when added to animal feed, can help reduce dietary methane production:

“Both krabok oil and coconut oil increased the rumen volatile fatty acids, in particular propionate and decreased acetate proportions. Protozoal numbers were reduced through the supplementation of a medium chain fatty acid source (coconut oil, krabok oil), with the strongest reduction by krabok oil.” [10]

Potential application for human digestion

These studies demonstrated how monolaurin may be applied to supplement animal feed to reduce targeted bacterial colonies and biofilms without negatively impacting “good” gut bacteria or contributing to antibiotic resistance.

While the studies are focused on the commercial application for farm animals, there may be potential to apply some of the lessons to humans. As stated before, same or similar bacteria can cause pathogenic infections in people. If monolaurin can effectively treat these bacterium in animal studies, there may be potential to apply to humans, but further research is needed. Read more about Monolaurin and its potential uses in the Essential Guide.

With all supplements, it is important that you consult a medical professional before beginning a supplement regimen.


  1. The Columbia Electronic Encyclopedia, 6th ed. 2012, Columbia University Press.

  2. Hook SE, Wright AG, McBride 1. “Methanogens: Methane Producers of the Rumen and Mitigation Strategies” Archaea, Volume 2010, Article ID 945785, 11 pages,

  3. Xuan Zhou, Leo Meile, Michael Kreuzer, and Johanna O. Zeitz, “The Effect of Saturated Fatty Acids on Methanogenesis and Cell Viability of Methanobrevibacter ruminantium,” Archaea, vol. 2013, Article ID 106916, 9 pages, 2013.

  4. Klevenhusen F, Meile L, Kreuzer M, Soliva CR. Effects of monolaurin on ruminal methanogens and selected bacterial species from cattle, as determined with the rumen simulation technique. Anaerobe. 2011 Oct; 17(5):232-8. doi: 10.1016/j.anaerobe.2011.07.003.

  5. Hammerum AM. “Enterococci of animal origin and their significance for public health.” Clin Microbiol Infect. 2012 Jul;18(7):619-25. doi: 10.1111/j.1469-0691.2012.03829.x

  6. C. R. Soliva, L. Meile, A. Cieślak, M. Kreuzer, and A. Machmüller, “Rumen simulation technique study on the interactions of dietary lauric and myristic acid supplementation in suppressing ruminal methanogenesis,” British Journal of Nutrition, vol. 92, no. 4, pp. 689–700, 2004.

  7. Fraser, S.L. “Enterococcal Infections” Medscape. Updated 30 July 2018. Last accessed 19 February 2019.

  8. Donavon J. Hess, Michelle J. Henry-Stanley, and Carol L. Wells. Surgical Infections. Volume: 16 Issue 5: October 5, 2015.

  9. Holly E. Saito, John R. Harp, Elizabeth M. Fozo. Enterococcus faecalis Responds to Individual Exogenous Fatty Acids Independently of Their Degree of Saturation or Chain Length. Appl. Environ. Microbiol. Dec 2017, 84 (1) e01633-17; DOI: 10.1128/AEM.01633-17

  10. Paul B. Eckburg, Paul W. Lepp, David A. Relman. Archaea and Their Potential Role in Human Disease. Infection and Immunity Feb 2003, 71 (2) 591-596; DOI: 10.1128/IAI.71.2.591-596.2003

  11. Ruzin A, Novick RP. Glycerol monolaurate inhibits induction of vancomycin resistance in Enterococcus faecalis. J Bacteriol. 1998 Jan;180(1):182-5.