In a 2016 article Bacteriocin production: a relatively unharnessed probiotic trait? a group of researchers in Cork, Ireland led by James W. Hegarty, are making a case for bacteriocins.
What are bacteriocins?
- Peptides produced by bacteria that can act against other similar bacteria; the producers remain immune.
- High in diversity: size, structure, mechanisms of action. Receptors are a few ways they differ.
- Influenced by environment: pH, temperature, growth medium.
Bacteriocins and probiotics:
- Assist in survival of bacteria which bore it
- Inhibit pathogens
- Signal the environment
Initial data on bacteriocin action:
The authors assert that while the majority of probiotics used commercially are in the genera Lactobacillus or Bifidobacterium, there exist very little data on bacteriocins from Bifidobacterium.
However, certain Lactobacillus salivarius strains produce known bacteriocins. The probiotic protected mice against a pathogen called Listeria monocytogenes infection.
Lactobacillus salivarius strains lessened metabolic abnormalities linked with obesity in a mouse model; Streptococcus salivarius promotes health in the oral cavity and gut.
Bacteriocins may target pathogens without disturbing beneficial colonies. For example, certain Enterococcus faecalis strains which express bacteriocin replaced other strains of E. faecalis which did not express bacteriocins. This could offer an alternative therapy for drug-resistant bacteria, a situation which is endangering more lives than ever.
In cancer, it is proposed that bacteriocins may impact cancer cells themselves or inhibit bacteria linked to cancer initiation. For example, Fusobacterium nucleatum has been linked to colorectal cancer.
Bacteriocins expand the potential in targeted disease prevention and treatment. Be sure to read the review article to broaden your understanding of challenges and possibilities. Also Hazem A. Fahim and colleagues from Beni-Suef University in Egypt have written an excellent summary of bacteriocins and how nanotechnology may enable more practical use.
Currently, bacteriocins are used as food preservatives and anti-biofilm agents. Limitations abound, however:
- High cost
- Breakdown by enzymes
- Interaction with other foods, wasting much of the bacteriocin
- Alterations during food processing
- Traditional purification makes for low yields
- Narrow spectrum of activity
Fahim and colleagues propose that nanoformulations may ease the path to better use of these valuable proteins.