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  • Writer's pictureTravis Cesarone

CBG and CBD as antibiotics, considering microbiome health

Updated: Jan 31, 2023

McMaster University released a popular study in 2020 discussing CBG’s ability to kill drug-resistant bacteria. But the problem with antibiotics is their broad effects that accidentally kill a lot of healthy bacteria. Published in the International Journal of Molecular Medicine, a new study assessed CBD and CBG as antibiotics and further tested their safety for the skin’s microbiome.

Cannabigerol (CBG) and cannabidiol (CBD) are popular cannabinoids found in various hemp breeds. And CBD is undergoing clinical trials as an ACNE treatment. Information on CBG’s action against microbiota is, on the other hand, promising, albeit limited to a few studies. Unfortunately, the research from McMaster University was coauthored by inventors of medications that mix cannabinoids with other antibiotics. (1)

The new study used 99% pure cannabinoids derived from chemical synthesis and cannabis plants, comparing their results. And CBDv was one of the only contaminants. This means that the entourage effect was omitted from the study, which is the whole plant’s collaboration of pharmacological mechanisms. And keep in mind that a pharmaceutical outfit partly conducted the study. (2)

Drug-resistant bacteria

The researchers tested cannabinoids against S. aureus, S. epidermis, and Streptococcus pyogenes, which are gram-positive species. Certain types of gram-positive bacteria require harsh antibiotics, although they can form a resistance to treatment. Staphylococcus aureus, for example, is often Methicillin-resistant and known as MRSA. It now requires a harsher antibiotic called vancomycin.

Earlier studies suggested that CBG inhibits drug-resistant bacteria with remarkable efficacy relative to vancomycin. The latest paper contests this, with results suggesting that the broad antibiotic is five times more potent than either cannabinoid or 300 times as strong against p. acnes. However, vancomycin is a last-resort antibiotic for gram-positive bacteria, particularly MRSA, due to its negative effect on good microbiota.

These organisms are still highly susceptible to CBD and CBG. Despite the less promising results, it only took 1 to 20 milligrams of either CBD or CBG to inhibit gram-positive microbiota. At those doses, cannabinoids, especially CBG, almost entirely reduced biofilm formation.

What else is in biofilm?

CBG and CBD further reduced biofilm comprised of gram-negative microbiota, including E. coli and P. aeruginosa, by 85%. Yet, these species withstood much higher doses of CBD or CBG compared to their gram-positive neighbors. The minimum dose of cannabinoid required to reduce these types of bacteria was around 160 milligrams. Whereas at least 1.5 grams was required to kill gram-negative microbiota. And CBG again displayed a greater effect than CBD, except against s. aureus growth.

You can grow biofilm at home just by neglecting your bong’s hygiene. But that habit leads to health risks and should be avoided due to the various types of harmful bacteria comprising biofilm. The study transfected human skin cells with MRSA and noted that CBD and CBG significantly reduce the inflammatory cytokine, IL-1a. Both cannabinoids further blocked the deadly bacteria by 90% in vitro at milligram concentrations.

CBG cultivars might inhibit biofilm growth more than CBD. (1-3) But no bong should have a microbiome. So one question demands an answer — do cannabinoids affect your skin’s microbiome?

The gut-brain-skin axis

The microbiome connects the skin, our largest organ, to the gut and brain. Good microbiota inhabiting and dominating the body’s exterior surface support brain and gut health. (4) A topical antibiotic will, therefore, deliberate mental and physical health if it kills enough good microorganisms.

The study concludes that CBD and CBG do not negatively impact the skin’s microbiome, despite their antibiotic properties against various types of bacteria. Cannabinoids inhibit healthy microbiota, including s. epidermis, far less than MRSA strains, for example. With that said, some emulsifiers used to formulate CBD are known to contribute to a state of unbalanced microbiota, known as dysbiosis. (1, 5, 6)


The recent research was conducted by Amyris Bio Products. (1) Previous research from McMaster University was authored by inventors of antibiotic medications. (3) The review focuses on cannabinoids and not cannabis formulations with anti-bacterial terpenes, such as a-pinene. (4) The in vitro experiments discussed herein exclusively serve as practical and necessary first steps before clinical trials.


  1. Farha, M.A.; El-Halfawy, O.M.; Gale, R.T.; MacNair, C.R.; Carfrae, L.A.; Zhang, X.; Jentsch, N.G.; Magolan, J.; Brown, E.D. Uncovering the hidden antibiotic potential of cannabis. ACS Infect. Dis. 2020, 6, 338–346.

  2. Luz-Veiga, M.; Amorim, M.; Pinto-Ribeiro, I.; Oliveira, A.L.S.; Silva, S.; Pimentel, L.L.; RodríguezAlcalá, L.M.; Madureira, R.; Pintado, M.; Azevedo-Silva, J.; et al. Cannabidiol and Cannabigerol Exert Antimicrobial Activity without Compromising Skin Microbiota. Int. J. Mol. Sci. 2023, 24, 2389.

  3. Aqawi M, Sionov RV, Gallily R, Friedman M, Steinberg D. Anti-Biofilm Activity of Cannabigerol against Streptococcus mutansMicroorganisms. 2021;9(10):2031. Published 2021 Sep 25. doi:10.3390/microorganisms9102031

  4. Russo EB. Cannabis Therapeutics and the Future of Neurology. Front Integr Neurosci. 2018;12:51. Published 2018 Oct 18. doi:10.3389/fnint.2018.00051

  5. Furuhashi H, Higashiyama M, Okada Y, et al. Dietary emulsifier polysorbate-80-induced small-intestinal vulnerability to indomethacin-induced lesions via dysbiosis. J Gastroenterol Hepatol. 2020;35(1):110-117. doi:10.1111/jgh.14808

  6. Sharma A, Lee J, Fonseca AG, et al. E-cigarettes compromise the gut barrier and trigger inflammation. iScience. 2021;24(2):102035. Published 2021 Jan 6. doi:10.1016/j.isci.2021.102035

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