Writing exercise #15

One project that I would be excited about would be the research into the different gut microbiota compositions that lead to specific mental disorders. Mental health is currently treated through the use of counseling and medications. It has been suggested that these medications are symptom-relieving short term, but can actually exacerbate them long term. By being able to link specific dysbiotic compositions to specific mental disorders, we are able to individualize treatment plans to treat the specific dysbiosis without possibly progressing the mental conditions. This would change the way that we currently treat mental disorders and may change the field entirely.

Writing exercise #14

Cancer, mental disorders, Crohn’s, GI imbalance, immune system disorders

Referring back to Writing Exercise #1, I am able to be exact when stating that these are non-infectious diseases influenced by microorganisms. For writing exercise #1  I was able to list non-infectious diseases but was not able to state whether they were influenced by microorganisms or not. One big topic that will remain on my mind will be the sheer magnitude of the interaction between our microbiota and entire health. I think the biggest asset, however, is the ability to read and interpret scientific works such as research studies,  reviews, case studies, and survey studies and am able to more easily make my own conclusion based on the findings.

Writing Exercise #13

Can experiments detect differences that matter? This question refers to the sensitivity of technology and its ability to detect significant differences.  Hanage states that even within species, bacterial strains’ genes differ greatly.

Does the study show causation or correlation? Hanage used the example of a study which explored the diets of seniors, altering and causing dysbiosis of the gut microbiota, thus, causing poor health. Yes, the conclusion fit the results, but Hanage argues that due to their age, seniors have poor health which altered the gut microbiome. The reverse causality was not explored or mentioned. We must keep other factors in mind when discusing results and planning experiments.

What is the mechanism?  Hanage argues that we must “pinpoint both whether the microbiome effects human health, and excactly how it does so” by  focusing on the actions of specific components of the microbiome. We must be aware of how said components effect the microbiome in order to assess the importance of the results.

How much do experiments reflect reality? We must always keep this question in mind when discussing results. With microbiome related experiments, it is almost impossible to recreate the gut enviornment in a lab. Considering this, lab results may not always be reflected in clinical trials, or real-life uses.


Could anything else explain the results? Similarly to causation vs correlation, this question refers to other factors potentially affecting the results. Hanage explains that there are sometimes other more important facorsthat may explain results.


When discussing controversy, I think the most helpful question is “Does the study show causation or correlation?” This is because the human body is immensly complex and contains an plethora of interconnecting mechanisms. Yes, results may back up conclusions, but there is usually more to the picture. Such as in Hanage’s example, the results clearly backed up the conclusion, but the experimental designer made a mistake by not stepping back and exploring other potential causes of the results.

Writing exercise #12

The relationship between mental health states and the gut microbial community is referred to as the gut-brain axis. This relationship is bi-directional meaning that the brain influences the gut microbiota and the gut microbiota influences that brain. The gut microbiota influences the brain through systemic means, using small molecules such as neurotransmitters, and through neural means, using sympathetic nerves. It is hypothesized that the gut microbiota can influence mental conditions such as depression, anxiety, and even autsim spectrum disorders. The brain influences the gut microbiota through neural means specifically through the vagus nerve and other sympathetic nerves, and also through the use of small molecules. By working towards a symbiotic gut microbiome, it is believed that mental health states are improved. There is believed to be a link between our microbiota and potentially treating schezophrnisa, bi-polar disorder, PTSD, OCD, eating disorders,  and other mental heath conditions. This topic is still very widely controversial but current evidence shows lots of promise.