Yes, there is!
Our immune system continuously produces substances (charged proteins called defensins) whose job it is to fight against bacteria, fungi, and viruses.
The immune cells release these defensins into bodily fluids, where the “defensin cocktail” protects the body from assailants such as bacteria, fungi, and/or viruses.
Defensins are about as old as insects, so they form an old component of our immune system; this means that they can be found throughout the entire animal kingdom. The immune cells release these proteins in high concentrations, for example, to the eye fluid, the saliva, and the lung and vaginal mucus. These proteins can be found wherever our body has to fight intruders!
The development of defensins only functions well in a healthy body. A healthy body is understood as balanced interaction among our organs. Thus, for example, the non-microbial digestion of food takes place in the small intestine, which the microbial digestion dominates in the colon. The colon is a fermentation organ, so to speak. When an "imbalance" develops between the colon and the small intestine, it may negatively affect defensin production. A decreased defensin level results in less resistance against microorganisms.
So how does an imbalance develop?
For example, intolerance against carbohydrates leads to excessive fermentation in the colon, which in turn leads to excessive flatulence. Flatulence means that the colon is – figuratively speaking – inflated; the closing mechanism between the small intestine and the colon doesn’t function properly anymore, and bacteria migrate from the small intestine to the colon. This causes an infection of the small intestine and, together with reduced production of defensins, this combination frequently leads to colon cancer over time.
Our cells use various substances to communicate among themselves – the umbrella term for these substances is "cytokines"; the defensins are a group of cytokines. These cytokines lead to the activation of signaling pathways in the cell.
Try to imagine it this way: Cell A (an immune cell) tells Cell B (an oral mucosa cell): "Produce more mucus, because there are bacteria present." However, Cell A doesn’t talk to Cell B, but releases signaling molecules called cytokines.
Like a key-lock system, these cytokines have the effect that signaling pathways are activated in Cell B; in the end, this leads to increased production of mucus. Think of the signaling pathways as a factory where the boss gives the foreman an order, which the foreman then announces over the microphone. Right away, the workers get busy, etc... The same signaling cascade takes places in the cell.
Interestingly, it was found that similar signaling pathways are activated by bacteria in the gingival pockets (in patients with periodontitis) as with cancer patients. Hence, there may be a correlation between these diseases.
