- An average human being is composed of roughly 10 trillion cells
Cells have a fairly high probability of mutation as they divide. That is just the way the system works; as bits of genetic material attach in sequence to complete a new DNA strand, there is a fairly high probability of a coding error.Gut cells are especially at risk for mutation, due tot he fact they are in contact with the waste products of our digestive process, many of which may have mutagenic qualities.
Cells have mechanisms to watch for these errors and truncate them;strip of the bad code and reconstruct), or destroy the new cell.
- The gut has a series of valleys, called crypts, and peaks, called villi.
In the crypts there are groupings of stem cells (stem cells are generic cells which can become/create any(totipotent) or many(pluripotent) types of cells in the body. Much of stem cell research is about controlling these cells, so we can create new organs and other body parts, which could be a genetic match to your body, thereby taking care of the whole rejection issue.). These stem cells duplicate themselves at a relatively slow rate, and have a relatively long lifespan, to reduce the probability of mutations occurring. These cell produce the various specialized gut cells (we'll call them daughter cells), which work their way up to the top of the villi, and make up the bulk of the gut cell tissue.
Some of the specialized gut cells produce a mucus substance (mucin) which forms a barrier (a slimy force field) between the stem cells and the contents of the intestines, thsu preventing these stem cells from coming in contact with potential mutagens.
Since the stem cells produce a relative small quantity of cells, most of the cells which make up the gut are the result of an series of exponential divisions of the daughter cells, which the stem cell originally produced.
These cells work their way up the villi, where they become exposed to the contents of the gut. At this point, they are now a high risk for mutation, so they ... kill themselves (apoptosis), to be replaced by newer cells. This cycle takes 3-4 days.
- The gut is also home for a host of bacteria. There are more bacteria in the gut, than there are cells in the body (roughly ten time more, in fact). These bacteria perform all kinds of tasks, like breaking down stuff our body can't, extracting use nutrients we couldn't otherwise get access to. They help train our immune system, they help to prevent the growth of pathogens, and they may play a role in the prevention of allergies and Inflammatory Bowel Disorders.