Enterococcus faecalis: friend or foe?
Enterococcus faecalis, a bacterium that resides in the intestines of mammals, plays a significant role in the human body. But how exactly? And what makes this bacterium both beneficial and potentially dangerous?
What is Enterococcus faecalis?
Enterococcus faecalis is a bacterium naturally found in the gastrointestinal tract of mammals, including humans. The name literally means “internal sphere in feces,” referring to the location where this bacterium is often found. Although Enterococcus faecalis can also be found in soil and water, it primarily contributes to food digestion in our bodies.
What does Enterococcus faecalis do?
This bacterium feeds on sugars, glycerol, and other substances in our intestines, helping to digest food. One of the most fascinating functions of Enterococcus faecalis is its ability to produce vitamin B12 (cobalamin). This vitamin is essential for red blood cell production and nervous system function. However, while Enterococcus faecalis produces vitamin B12, humans can only absorb this vitamin in the small intestine. Unfortunately, this means the vitamin produced by the bacterium cannot be directly utilized by our bodies. Nevertheless, Enterococcus faecalis plays a crucial role in maintaining a healthy microbiome.
Enterococcus faecalis outside the body
Enterococcus faecalis is not only useful within our intestines but also has applications outside the body. For instance, the hoopoe, a bird species, uses this bacterium to protect its eggs. The bacteria in the hoopoe’s preen gland produce bacteriocin, a protein that kills other harmful bacteria, safeguarding the eggs from infection.
Vitamin B12 and the animal kingdom
In some animals, such as ruminants, the system works differently. For example, anoas—an animal you can see at ARTIS Zoo—can absorb vitamin B12 thanks to the microbes in their rumen. This explains why some animals eat their own feces (coprophagy) to reabsorb nutrients. For humans, this means we depend on food sources like meat or dairy to meet our vitamin B12 needs.
A helpful housemate or a threat?
While Enterococcus faecalis naturally resides in our intestines and aids in food digestion, some strains of this bacterium are resistant to antibiotics. This can pose a serious problem, especially when resistant bacteria are spread via insects like houseflies. A well-known dangerous strain is Vancomycin-Resistant Enterococcus (VRE), which is particularly difficult to treat.
Friend or foe?
Enterococcus faecalis is a fascinating bacterium that can be both helpful and harmful. As a resident of our microbiome, it helps digest food and produces essential vitamins, yet certain strains can cause serious health issues. Continued research into the positive and negative aspects of this bacterium remains crucial for understanding our microbiome and combating antibiotic-resistant bacteria.