Activity of cannabidiol on ex vivo amino acid fermentation by bovine rumen microbiota

Authors: LAKES, JOURDAN - Orise Fellow; Harlow, Brittany; Flythe, Michael

Submitted to: Fermentation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2024
Publication Date: 5/21/2024
Citation: Lakes, J.E., Davis, B.E., Flythe, M.D. 2024. Activity of cannabidiol on ex vivo amino acid fermentation by bovine rumen microbiota. Fermentation. 10(6). Article 267. https://doi.org/10.3390/fermentation10060267.
DOI: https://doi.org/10.3390/fermentation10060267

Interpretive Summary: A group of bacteria within cattle remove protein from the animal's available pool of nutrients by amino acid fermentation, which results in the production of ammonia that is excreted from the animal in the urine. This negatively impacts the ability of beef cattle to gain weight and this issue often results in the need to supplement feed with additional protein. The waste product can also reach the groundwater. Therefore, the presence of these organisms in cattle is wasteful and their control beneficial. Amino acid fermenting bacteria can be controlled with antibiotics, but that practice linked to increased antimicrobial resistance. Plant-derived alternatives can be supplemented into the diets of cattle and may offer worthwhile alternatives to traditional antimicrobial use, thus reducing the risk of antimicrobial resistance development. The current study sought to investigate the role of cannabidiol as an alternative compound to antibiotics for the control of amino acid fermenting bacteria in beef cattle. Rumen fluid samples, containing amino acid fermenting bacteria, were collected from Angus x Holstein steers in culture media selective for testing in the laboratory. These cultures were then treated with one of five concentrations of CBD, incubated for 24 h, after which ammonia production and viable (living) number of cells were measured. The data demonstrated a reduction in ammonia produced at the highest concentration of CBD (860 µg/mL), and indistinct changes in viable number of amino acid fermenting bacteria cultured from the rumen fluid. Thus, CBD does not appear to be a viable candidate for the control of amino acid fermenting bacteria, as a community, in beef cattle.

Technical Abstract: Amino acid fermenting bacteria are wasteful organisms within the rumens of beef cattle as they remove amino-nitrogen from the nutrients available via ammonia production excreted renally by the animal in the urine. Current practices to control this guild often utilize broad-spectrum antimicrobials, which pose an increased risk of antimicrobial resistance. Plant-derived alternatives, which can be supplemented into the diets of cattle may offer a worthwhile alternative to traditional antimicrobial use. This study sought to investigate the role of cannabidiol (CBD) as a viable terpenophenolic antimicrobial. Ex vivo cell suspensions were harvested from the rumen fluid of Angus x Holstein steers in non-selective media with amino acid substrates. The suspensions were treated with five concentrations of CBD (860 µg mL-1 – 0.086 µg mL-1), incubated (24 h), after which ammonia production and viable number of cells per substrate and treatment were measured. The data demonstrated a ~ 10 – 15 mM reduction in ammonia produced at the highest concentration of CBD, and negligible changes in viable number of amino acid fermenting bacteria. CBD does not appear to be a viable terpenophenolic candidate for control of amino acid fermentation in beef cattle.