08/02/2024 Pigs Poultry

Bacterial challenges with gram-positive bacteria in monogastric animals have a large impact on several aspects of animal husbandry, including higher medication costs, development of antibiotic resistance and reduced growth rates and feed efficiency. Among the many gram-positive bacteria that have a devastating effect on animal health and production, the following are the most common:

  1. Staphylococcus spp (facultative anaerobic cocci)
  2. Streptococcus spp (non-motile, non-spore-forming facultative anaerobic cocci)
  3. Clostridium spp (obligate anaerobes)

Arthritis, synovitis, and osteomyelitis are well-known consequences of staphylococcal and streptococcal infections in poultry. Especially, heavier birds often suffer from bumblefoot (pododermatitis) due to these bacteria. Clostridia, which affect the intestinal health of chickens, contribute to reduced feed intake and growth performance. These pathogens not only facilitate mixed infections in poultry, but also increase the susceptibility for potential viruses to infiltrate host cells, resulting in significant financial losses. Although these bacteria are usually considered normal inhabitants of the chicken gut, any impairment of immune activity can lead to acute disease outbreaks. In particular, these microbes pose a potential threat in the context of drug resistance and MRSA issues.

Streptococcus suis (an alpha-haemolytic Streptococcus) is by far the most important pathogen of infectious diseases in pigs and mainly affects lactating and newly weaned pigs. S. suis infections are associated with septicaemia, meningitis, polyserositis, polyarthritis and bronchopneumonia. Infections caused by S. suis, and Clostridia are the main reasons for the overuse of antibiotics in pigs, underlining the need for effective solutions to address these challenges.


Medium-chain fatty acids (MCFA) are a group of aliphatic acids with 8 to 12 carbon atoms and occur naturally in edible fats such as coconut oil and milk fat. MCFAs are considered safe and green ingredients in the food industry (Dayrit, 2015).

While short-chain organic acids such as formic, acetic, propionic, and lactic acid exhibit their highest antimicrobial efficacy in the acidic environment of the stomach, medium-chain fatty acids (MCFAs) display their activity even deeper into the intestinal tract. MCFAs are absorbed directly into both the bloodstream and the lymphatic system.

MCFAs possess antimicrobial and antiviral properties. Their monoglycerides, mono-esters of MCFAs, are highly effective in killing pathogens, specifically when the functional group is located at the alpha carbon (Carbon Number 1), known as alpha monoglycerides or 1-monoglycerides. The ground-breaking work of John Kabara and colleagues revealed that MCFAs, particularly lauric acid (C12), have the most powerful bacteriostatic activity against gram-positive organisms. Additionally, they demonstrated that alpha-monolaurin (the monoglyceride of lauric acid (B)) is more active than the free acid (A). Of crucial importance is to mention that both lauric acid and alpha-monolaurin are recognised by the FDA as Generally Regarded As Safe (GRAS), guaranteeing safe use.



The schematic diagram illustrates the mode of action of monoglycerides on gram-positive bacteria. These monoglycerides interact with lipids in the membrane, disrupting its integrity and permeability, ultimately leading to bacterial death.

Once inside the bacterial cytosol, monoglycerides are split into glycerol and free fatty acids which subsequently dissociate. The free protons lower the pH of the bacterial cytosol, depleting ATP through proton motive force. Simultaneously, the anions form a complex with bacterial DNA, inhibiting replication. This dual working mechanism leads to bacterial death.

Due to the amphiphilic nature of both monoglycerides and phospholipids, monoglycerides can be absorbed into the membrane, increasing the permeability of the membranes.

Int. J. Mol. Sci. 2018, 19, 1114; doi:10.3390/ijms19041114



Using alpha-monolaurin can enhance the immune status of animals. A healthy gut is important for an overall good immune response to vaccinations, including respiratory and systemic. In chickens, the majority of antibodies is produced in the gut following vaccination. If there is a bacterial challenge in the intestines, the immune system is already occupied with these bacteria, hampering its ability to provide an effective response to vaccine antigens. Finally, bacterial toxins can negatively influence immune cells. Moreover, another study proposed that the antimicrobial effect of alpha-monolaurin against bacteria is related to its interference with signal transduction and toxin formation (Projan et al., 1994).


The management of gram-positive bacterial infections in monogastrics is paramount for ensuring optimal livestock production. Olus develops and produces a range of innovative monoglyceride solutions, such as Elan®C12. The key benefits of Elan®C12?
  1. Exhibits robust antibacterial activity against gram-positive bacteria, including MRSA.
  2. Absorption through the lymphatic system enhances its effectiveness in the bloodstream, increasing its efficacy against systemic infections.
  3. Monoglycerides of lauric acid, particularly monolaurin, demonstrate higher activity and potency than as a free fatty acid.
  4. Recognized as Generally Regarded As Safe (GRAS) by the FDA.
By harnessing the synergistic effects of these organic acids and micro-ingredients, Elan®C12 promotes animal health, reduces the reliance on antibiotics to control bacterial infections and contributes to an improved defence mechanisms of the animal. The product is available in both dry and liquid form.

Want to know more about our monoglyceride solutions? Contact us for more information: Our experts will be happy to help you!



  • Kabara, J.J.; Swieczkowski, D.M.; Conley, A.J.; Truant, J.P. Fatty acids and derivatives as antimicrobial agents. Antimicrob. Agents Chemother. 1972, 2, 23–28.
  • Kabara, J.; Vrable, R.; Jie, M.L.K. Antimicrobial lipids: Natural and synthetic fatty acids and monoglycerides. Lipids 1977, 12, 753–759.
  • Kabara, J.J. Antimicrobial agents derived from fatty acids. J. Ame. Oil Chem. Soc. 1984, 61, 397–403.
  • Kabara, J.J. Structure-function relationships of surfactants as antimicrobial agents. J. Soc. Cosmet. Chem. 1978, 29, 733–741.
  • Kabara, J.J. GRAS antimicrobial agents for cosmetic products. J. Soc. Cosmet. Chem. 1980, 31, 1–10.
  • Dayrit, F. M. 2015. The properties of lauric acid and their significance in coconut oil. J. Am. Oil Chem. Soc. 92:1–15.
  • Conley, A.J. and Kabara, J.J. (1973) Antimicrobial action of esters of polyhydric alcohols. Antimicrob. Agents Chemother., 4, 501–506.



Muhammad Suleman – Regional Manager South East Asia and Middle East

Muhammad Suleman, Regional Manager for Southeast Asia and the Middle East, has joined the Olus team since 2023. His involvement with Olus brings a wealth of experience and a deep passion for the poultry industry. With years of experience and extensive knowledge of the complexities of poultry farming, Muhammad has a deep understanding of the market. Within Olus, he is actively involved in developing new feed additives and exploring nutritional strategies to improve gut health and performance in a sustainable way.