Month: March 2018

I may be biased due to the topic I chose for my final review essay, but I would love to be able to allocate funding for research dedicated to discovering the connection between our microbial populations and brain-related disorders such as Alzheimer’s disease. The amount of people affected by incurable neuro-degenerative disorders is astronomical, with future prospects not looking much better. Delving into the research regarding the pathogen hypothesis, it revealed numerous proof of concept studies that necessitate funding for the next level of research. With the current line of thinking (amyloid cascade hypothesis) bringing no successful treatments to fruition, I believe it is definitely time to broaden our horizons with a new perspective that considers microbes as the possible catalyst and route to treatment. If nothing else, it would certainly give us the opportunity to further understand how microbes could influence the human brain, and vice versa, as there are numerous other disorders that still require answers (e.g., Parkinson’s, Huntington’s, depression, anxiety, etc.).

Non-infectious, microbial-related diseases I can name: asthma, various allergies, some cancers (e.g., gastric cancer), an array of gastrointestinal disorders (e.g., IBD and CD), brain/mental disturbances (e.g., depression, anxiety, Alzheimer’s disease), immunodeficiency diseases (due to lack of proper immune system development in relation to factors such as C-section births).

Looking back at my first post, what I know now about the topic far outweighs what I came into the course with. I could barely name any examples that the writing exercise called for, and I was not aware that microbes and non-infectious diseases were even associated with each other. Having now experienced the course, it’s pretty crazy that not so long ago I was so uninformed about the incredible role microbes can play in our bodies. Learning that this topic has gained such attention recently, even being deemed our “hidden metabolic organ,” makes me wonder how I have gone so long knowing so little. While my BHS major brought me to this course, it is only one of several options I could choose from in a required field.

We read articles that asked us to broaden our horizons and consider the significance of microbes dwelling in our gut, as well as ones that appeal to our analytical nature; asking us to remain cautious and pragmatic before jumping to any conclusions too wild. I think I will take both sides of the argument with me when I leave this course, as they both deserve a place in the reader’s toolbox when encountering new scientific literature and concepts.

• Can experiments detect differences that matter?
  • Many experiments still rely on outdated techniques or standards that fail to meet up to the level of detail and accuracy required by the public and researchers of this era. In that, experiments that aren’t modernly designed might reach conclusions that have neglected important details regarding the subject matter. Specifically, results could lend to generalizations about a certain phyla of bacteria, wherein the multitude of strains it encompasses actually does not meet conclusions made by the researchers.

• Does the study show causation or correlation?
  • Though the two relational classifications are widely acknowledged as important to distinguish between, it can often be a difficult task. Categorizing two variables as having a causal link when they are merely just victims to same-place-at-the-same-time circumstances would be a significant mislabelling that could inspire additional unnecessary research.

• What is the mechanism?
  • It is important to define the process by which the science in question actually works. To outline and understand the cause and effect being published in the study/research will eliminate some mystery as to if the two variables are actually related in a causal way. Determining each step of the mechanism from beginning to end will validate the conclusions reached by the study, rather than simply stating two things are related due to their mutual presence.

• How much do experiments reflect reality?
  • While significant and groundbreaking discoveries can be made during research projects/studies, it is not always clear if the given results/findings hold the same significance when applied to human life. For example, most experiments use specific animals to reach their conclusions, but it must be taken into account that this does not efficiently mirror an experiment carried out on humans. It must be acknowledged in the work and the differences should be explained to better keep the data in perspective.

• Could anything else explain the results?
  • Similar to the question of cause or correlation, an audience should ask if the circumstances hold any variables that could be blamed for the ending data. If there are other influential things present (e.g., environmental, etc.) then it is not a fair assessment or true discovery.

 

Since the substantial, recent increase in attention towards the human gut microbiome, ample amounts of research has been put forth in pursuance of fully understanding the  complex relationship between our metabolic processes and the commensal bacteria dwelling in the gastrointestinal tract. In realizing the many regulatory roles our microflora play in our most significant bodily mechanisms. As more information has accrued, researchers have turned their attention to the possibility that our hidden metabolic organ could influence our most protected organ: the brain.

Through the newly recognized microbiota-gut-brain axis, our microbes have established mechanisms by which they can exert their influence over the brain from their long distance domain. Having shown the ability to secrete numerous chemicals, researchers have further identified that a portion of those produced can be used to communicate with the brain via blood or neurons. In regards to the latter, the tenth cranial nerve, known as the vagus nerve, is the only cranial nerve to leave the brain and penetrate the diaphragm. This gives our microbes a direct line to our nervous system, facilitating action potentials via neurotransmitter release that can show direct consequence to emotions controlled by the central nervous system (1, 2).

A few of the chemicals released by our microbial communities that can regulate our mood (and the disorders caused by its alterations) are serotonin, dopamine, and gamma-aminobutyric acid (a.k.a. GABA). Differing the concentrations of these chemicals can control appetite-related signals, changing one’s perception of fullness and digestion. Manipulation of these chemicals can also contribute to the development of a variety of intestinal disorders that show strong correlation to depression and anxiety, as well as other complex mental disturbances, often treated by medications that oppose the effects relayed by the bacteria (2).

Communication between the gut and the brain is not limited to one direction, but is in fact a bidirectional relationship. Mental status generated by the structures and chemicals within the brain can also have an effects on the strains of bacteria that constitute our gut microbiome.  In particular, studies have been dedicated to showing how stress can impact microbe populations. Resulting alterations to those present have yielded lowered immune systems (a system that microbes contribute to), decreased protection from gastrointestinal diseases, etc.

In both directions, the relationship can be beneficial or harmful. Detrimental diseases of the psyche can lend to intestinal consequences or be caused by the bacteria there. On the same note, a strong microbiome can help improve mental status as well.

 

(1) Mayer EA, et al. 2014. Gut Microbes and the Brain: Paradigm Shift in Neuroscience. The Journal of Neuroscience, 34(46): 15490-15496

(2) Smith PA. 2015. Can the Bacteria in Your Gut Explain Your Mood? New York Times Magazine, https://www.nytimes.com/2015/06/28/magazine/can-the-bacteria-in-your-gut-explain-your-mood.html

I’ve always known that I am hypercritical or my own writing style and that I find it hard to half-ass large writing assignments like the one assigned to us. This definitely confirmed that I am just as hard on other writers as well.

To begin with, I had a hard time giving much of a review to the first paper at all, because the entirety of the draft was two vague paragraphs and an equally vague outline for the remainder, and a grand total of 3 references. Many of the questions weren’t applicable and I found myself wondering if I would lose points as well for not having much to say about this largely incomplete paper.

The second paper, however, I had to hold myself back from tearing into bits. I tried to be as gentle as I possibly could while critiquing this piece, because it felt rude to come in as an outsider and tell a stranger how I felt about their writing. Except this piece was truly appalling. Despite it being anonymous, the author still included their name on the piece and based of the ethnic origins, I assumed English was their second language so I tried not to be overly critical of the grammar — not much they can do about that. However, the paper felt like I was reading someone’s stream of consciousness. Many topics discussed in class were dumped into the paper and I just wanted to shout “THAT HAS NOTHING TO DO WITH YOUR PAPER! STOP TRYING TO DISTRACT ME!” But that seemed rude so I left that out of the peer review. It was hard to critique individual aspects of a paper that I wanted to tell the author to burn and completely rewrite.

 

That sounds harsh, I’m sorry.

The peer review process is put in place to evaluate the legitimacy of statements made and results found in a study. It is important to be able to distinguish what the purpose of the paper is and what the authors’ thesis statement is going into it (if there is one).

Anything stated by fact needs to be backed up by a legitimate reference to keep false information from being accepted as anything else but false. The entirety of the references list, in fact, should be combed through to ensure the efficacy of the claims they supposedly support within the paper.

Any informal language used should be corrected and any overly scientific language that the author cannot expect the audience to know should be explained.

The benefit of having a peer review system in place is that it can confirm the validity/credibility of the results rendered so that anyone referencing this paper down the line, or just reading it to gain knowledge in general, is not incorrectly informed. It stops false information from essentially snowballing.