We’re not the only ones to benefit from essential oils – chickens do too!


When I recently came across this new article in Nature (1), it got me thinking back to the days when I worked in the lab, studying Clostridium perfringens and chickens using carvacrol.

Essential oils (EOs) have been known for their antibacterial properties for some time now. Major components of EOs, like thymol and carvacrol, are common components in thyme and oregano (2). Besides improving the intestinal integrity and strengthening the mucosal barrier (3.4), EOs have been shown to improve cellular and humoral immunity (5,6) and modulate immunity-related gene expression in chickens (7).

This article looked at whether blends of EOs (25% thymol and 25% carvacrol) protected chicks from severe necrotic enteritis (NE) when challenged with C. perfringens (1).

C. perfringens is a normal inhabitant of the gut, and the name perfringens means “breaking through” as a reference to the way these bacteria destroy or break through muscle tissue during clostridial myonecrosis. It is a ubiquitous organism that has the widest environmental distribution of any pathogenic microorganism (8). C. perfringens also produces several exotoxins, including β2-toxin, which is associated with diseases of the gastrointestinal tract, ranging from diarrhea to severe necrotic enteritis (NE) (9,10).

In the poultry industry, NE is one of the most infectious diseases, causing estimated damages of around $6 billion globally due to treatment or productivity losses (11,12). Previous studies with broiler chickens showed that a challenge with C. perfringens resulted in a significant increase in bacterial translocation, which not only leads to damage in the intestinal mucosa, but also had a negative impact on the growth of the chickens (13–18).

Using the new QIAamp Fast DNA Stool Mini Kit for genomic DNA isolation from the ileum of the chicks and the QIAquick PCR Purification Kit to purify the 16 S rRNA gene, the study showed that intestinal lesions and mortality were significantly reduced when chicks were fed thymol and carvacrol prior to infection. These dietary supplements positively altered the microbial population in the ileum and significantly reduced the effect of NE caused by C. perfringens (1).

For more information on the QIAamp Fast DNA Stool Kit, you can either download our dedicated product profile describing the kit, or technical note showing comparison data versus the QIAamp DNA Stool Mini Kit.



  1. 1. Yin, D. et al. (2017) Supplemental thymol and carvacrol increases ileum Lactobacillus population and reduces effect of necrotic enteritis caused by Clostridium perfringes in chickens. Scientific Reports. 7, DOI:10.1038/s41598-017- 07420-4.
  2. 3. Bassole, I.H. and Juliani, H.R. (2012) Essential oils in combination and their antimicrobial properties. Molecules. 17, 3989–4006.
  3. 3. Placha, I. et al. (2014) Effect of thyme essential oil and selenium on intestine integrity and antioxidant status of broilers. Br. Poult. Sci. 55, 105–114.
  4. 4. Wlodarska, M. et al. (2015) Phytonutrient diet supplementation promotes beneficial clostridia species and intestinal mucus secretion resulting in protection against enteric infection. Sci. Rep. 5, 9253.
  5. 5. Lee, S.H. et al. (2011) Effects of dietary supplementation with phytonutrients on vaccine-stimulated immunity against infection with eimeria tenella. Vet. Parasitol. 181, 97–105.
  6. 6. Awaad, M.H.H. et al. (2014) Effect of a specific combination of carvacrol, cinnamaldehyde, and capsicum oleoresin on the growth performance, carcass quality and gut integrity of broiler chickens. Vet. World. 7, 284–290.
    7. Kim, D.K. et al. (2010) High-throughput gene expression analysis of intestinal intraepithelial lymphocytes after oral feeding of carvacrol, cinnamaldehyde, or capsicum oleoresin. Poult. Sci. 89, 68–81.
    8. Cato, E.P. et al. Bergey’s Manual of Systematic Bacteriology 1984. vol 2 Williams and Wilkins, Baltimore:1141-1200
    9. Manteca, C. et al. (2002). A role for the Clostridium perfringens b2 toxin in bovine enterotoxaemia? Vet Microbiol. 86, 191–202.
    10. Waters, M. et al (2003). Genotyping and phenotyping of beta2-toxigenic Clostridium perfringens fecal isolates associated with gastrointestinal diseases in piglets. J Clin Microbiol. 41, 3584–3591.
    11. Wade, B. & Keyburn, A. (2016). The true cost of necrotic enteritis.
    12. Flores-Diaz, M. et al. (2016) Role of Clostridium perfringens Toxins in Necrotic Enteritis in Poultry. Microbial Toxins. 1-16.
    13. Liu, D. et al. (2010) Exogenous lysozyme influences Clostridium perfringens colonization and intestinal barrier function in broiler chickens. Avian Pathol. 39, 17– 24.
    14. Du, E. et al., (2015). In vitro antibacterial activity of thymol and carvacrol and their effects on broiler chickens challenged with Clostridium perfringens. J. Anim. Sci. Biotech. 6, 58–71.
    15. Du, E. et al. (2016) Effects of thymol and carvacrol supplementation on intestinal integrity and immune responses of broiler chickens challenged with Clostridium perfringens. J. Anim. Sci. Biotechnol. 7, 19–29
    16. Dahiya, J.P. et al. (2006) Potential strategies for controlling necrotic enteritis in broiler chickens in post-antibiotic era. Anim. Feed Sci.Technol. 129, 60–88.
  7. 17. Guo, S. et al. (2015) Inflammatory responses to a Clostridium perfringens type a strain and alpha-toxin in primary intestinal epithelial cells of chicken embryos. Avian Pathol. 44, 81–91.
    18. Van Immerseel, F. et al. (2009) Rethinking our understanding of the pathogenesis of necrotic enteritis in chickens. Trends Microbiol. 17, 32–36.


Kjell Kirschbaum

Kjell Kirschbaum, M.Sc., is a Global Market Manager based in QIAGEN’s Venlo office, the Netherlands. He trained as a bioveterinary scientist at the University of Utrecht and has hands-on experience in nucleic acid and protein purification, cell culture, PCR and qPCR technology. Kjell joined QIAGEN in 2011 as a CRM specialist, regularly interacting with customers about their day-to-day experimental needs and offering relevant solutions. Currently, he is involved in managing global projects for sample preparation and automation technologies.

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