It is interesting to see how people classify and doing great work on the bacteria inside the human body, for example, probiotics and pathogenic bacteria. We always consider the pathogenic bacteria is the thing harmful to human, is there any probability that the pathogenic bacteria could benefit the human body by secreting some unknown compounds or kill some other parasites or virus. The process to determine the affection is hard, it could explain  why scientist always like to determine a narrow field of what they want to do. Besides the wide range of possible results, the individual differences are also hard to test and collect as a reliable list. 

For the testing of effect of pathogenic bacteria, the variable of techniques  needs to be used, perhaps it needs to develop new strategy to collect the data obtained and creating a new program for the similarity analysis. The following wide range of possible consequence of different pathogenic bacteria application is also needed new program and technique developed to analysis. However, for avoiding the individual differences, the scientists could build an animal model by cloning, which gives an identical condition for the test. 

The further application of the brainstorm to the final essay could be explaining the details about the possible consequences, related researches finding and what new techniques are developed to collect the data for identical individuals under the variable condition test.