Bacterial toxins are by-products produced by pathogenic microbes that have taken up residence in the body. Bacterium can enter a host by various means, such as consuming contaminated food or water. Bacteria can also be introduced through mucous membranes, either by direct contact with the source or as a consequence of breathing in air-borne bacteria. The type of bacterial toxins released depends on the species of invading bacteria.
The cellular structure of bacterium also influences what kinds of bacterial toxins are produced. While all bacteria have single cells, there is a difference between their outer membranes that results in two classifications of bacteria: Gram-positive or Gram-negative. This distinction is visible when subjected to a “Gram stain,” which is an injection of a purple dye and a subsequent alcohol wash. Cells that retain the dye color are Gram-positive; those that do not are Gram-negative.
There are several types of bacterial toxins that may infect the human body at different sites. For instance, enterotoxins are toxic proteins generated in the intestines. Neurotoxins specifically target nerve cells. In addition, certain enzymes may be produced that can impair metabolic functioning. However, there are two primary groups of bacterial toxins that the above generally fall into in terms of mechanism: exotoxins and endotoxins.
Both Gram-positive and Gram-negative bacteria produce exotoxins, some of which are quite poisonous. For example, tetanus is caused by a bacterial toxin produced by Clostridium tetani that acts as a neurotoxin. Generally, the severity of symptoms and rate of recovery depends on how the infection occurs. However, it has been established that only a small amount of the pure toxin will prove fatal. Fortunately, this bacteria, as well as other exotoxins, can be adapted to produce preventative vaccines.
Endotoxins are released by Gram-negative bacteria. At first, they are not as aggressively toxic as exotoxins due to the fact they remain largely contained in the cellular walls of bacteria. However, as these cells complete their life cycle and die, the circulating volume of this toxin increases. In addition, they cannot be used to make vaccines.
Normally, the body attempts to eliminate bacterial toxins before they can cause harm. The immune system is the first line of defense, but it may become overwhelmed by the rate of bacterial replication. In fact, inflammation is an indication that bacterial overgrowth is occurring. In this case, the immune system will do the next best thing — move the bacteria out of the way. Usually, fat cells are the selected storage sites, which can lead to the formation of cysts and tumors.
Without intervention, bacterial toxins may eventually accumulate to the point where they move out of fat cells and into other tissues of the body. This process may take years to unfold, but a degenerative disease is often the end result. In fact, many age-related conditions and metabolic disorders are associated with the long-term buildup of these toxins, including heart disease, cancer, arthritis, and diabetes.