I came across a post in twitter shared by @thisischristina and a big thanks to her since while I read this, I found it very interesting to share it. So you can relate it with your current view now in 2013. Hope this interests you, if so then please do comment and find the full article as “main article” posted below this.
There has been an enormous numbers of bacteria making a favorable community from millions to trillions, and approximately 5.5 grams when dried. The question was obvious that time that how such large amount of bacteria prevailing there even though such large numbers are not taken in food. The conclusion was also much simple and that was the daily proliferation of the bacteria in the intestine. Although there are more facts to share like lots of early bacteria enters into the body from the first food after birth. So some early residents are still being present in the intestinal tract maintaining the versatile community.
Some of the bacteria which is identified as residents are B. bifidus, E. coli, B. lactis and Micrococcus ovalis. Among these, B. bifidus dominates among the intestinal flora and was found to be protective against growth of some other bacteria which might produce putrifaction or disease. There are lots of reasons for which B. bifidus sound to be prevalent in 1915 times research and it is well mentioned in the article.
Moving towards the distribution of bacteria, where stomach is practically sterile under normal conditions. The obvious explanation of this is the acidic gastric contents. Although sometimes when the acidic conditions becomes diminished due to some disease then the bacterial content increases. This is how those bacteria reach to the duodenum, and then to the lower levels. Large amount of bacteria are found in the ascending branch of the colon. Then from the ascending colon it moves and prevalent to the descending part.
Along with the disease causing ability of the bacteria, there are some of their community which helps the human being to assist the digestion of food through the elaboration of certain fragments and also these organisms are under normal conditions in the sense of the protection of host.
In conclusion intestinal bacteria may become menace to the host causing typhoid, dysentery, cholera, etc., although some organisms are found to be symbiotically faithful for the host. Hence we don’t be in contact with such diseases all the time. The article represents several theoretical experiments and observations of early research to understand the interactions.
A.I. Kendall. The Bacteria of the Intestinal Tract of Man. Science. Pg: 209-212 [Link: http://www.jstor.org/stable/1638807]