Author: Hung Phan

Numerous non-infectious diseases are influenced by the presence or absence of microbes. These diseases affect virtually every system conceivable in the human body. Thus, I will analyze these diseases and the system that they affect.

The gut microbiota is crucial to the human digestive system and overall well-being. Thus, the disruption of the gut microbiota often results in metabolism issues and a decrease in overall well-being. Examples of gut microbiota-related issues are Crohn’s disease, irritable bowel syndrome, inflammatory bowel disease, lactose intolerance, and numerous more.

Secondly, cancers can be influenced by the presence of several microbes. Helicobacter pylori-infected individuals have a higher likelihood of developing cancerous tumors from gastric ulcers. Human papillomaviruses are correlated with several cancers in females. The mechanisms of microbes in cancer development often include the transformation of the host cells’ genome, which can turn off apoptosis and increase cell division.

Certain diseases are caused by the immune response to bacterial infections, not by the bacteria themselves. Alzheimer’s disease is caused by the accumulation of beta-amyloid oligomers in the brain that cannot be completely cleansed by cerebrospinal fluid. A recent discovery noted that beta-amyloid oligomers can be the product of the immune response to pathogens in the brain.

Compared to Week 1, it looks like I gained more knowledge throughout the term about the mechanisms by which microbes influence human health. It is not just about the disruption of the microbiome anymore. The main takeaway for me this term would be there is no one-size-fits-all explanation for an illness, but rather it has to be looked at from many perspectives.

Mental illnesses are the result of the interaction between genetic vulnerabilities and environmental factors. The microbial community is an environmental factor that is considerable in overall mental health outcomes.

In one way, mental health can affect the microbial community. Stress causes the release of pro-inflammatory cytokines from lymphocytes. Chronic stress prolongs this release of cytokines and at a certain level, the adaptive immune system decreases in function. This means that pathogens may have an easier time causing infections in the body and cause dysbiosis, disrupting the delicate balance between the good and the bad bacteria. It is worth noting that it is not stress that causes this disruption, but rather the behaviors that we engage in during stressful times. Stress is linked to binge eating and poor choices in food, and these behaviors cause dysbiosis.

In another way, the microbial community can affect mental and neurobiological health. Cells release protective secretions during a viral infection, such as beta-amyloid oligomers. Cerebrospinal fluid cleanses these oligomers from the brain, but factors like subsequent infections, which can be attributed to stress, can result in a buildup of these oligomers. The result is this buildup is the development of Alzheimer’s disease, a neurobiological disease that causes memory loss and possible death.

A different composition of the microbial community can affect mental health. Inflammatory bowel disease is linked with dysbiosis and so is Autism Spectrum Disorder. Perhaps it is due to a genetic vulnerability or behaviors during the gestational period that affects the microbiota is implied as a correlational factor. Bifidobacterium can be particularly helpful in reducing anxiety, as a study points out that mice with this bacterium have a lesser increment in stress hormone compared to germ-free mice.

It is a two-way street when the topic of mental health and microbial community is brought up. Thus, it is crucial that researches in both directions are approached and studied.

W. P. Hanage comes up with a formula to understand scientific articles. This formula consists of questions to ask to address the validity and real-life application of these journals. Thus, this blog will address each question and the reasoning behind these questions.

Firstly, can the experiments in these scientific articles detect differences? Ultimately, every scientific article aims to use an experiment or existing evidence to address a question. What is the difference that we are observing in the data? What stands out? Do the elements that stand out have any significance in the whole picture? In conclusion, the first question asks the scientists to address and clarify the difference found in the data.

Secondly, does research suggest a correlation claim or a causation claim? A correlation is best explained as a factor is influencing the outcome of a phenomenon, but not directly causing it. For example, “smoking causes lung cancer” is a causation statement because there is numerous evidence to suggest so. However, “smoking may be related to impotence” is a correlation statement because there is evidence but it is not enough to establish a causal claim.

Thirdly, what is the mechanism? This question addresses how the outcome of an experiment can be addressed. Thus, this question ties back to the first question. Scientists observe the difference in the data obtained in their research. Then, it is now their time to establish a reason behind the difference in the data. The hypothesis comes into play here, as it provides an educated prediction as well as an explanation.

Fourthly, how much do experiments reflect reality? This question addresses how the experiment relates to real life. An explanation may apply to a single case, but not a different case. For example, medication dosage is different between people of different weights and ages. 1000 milligrams of paracetamol is helpful to reduce pain in adults and children over 16. But what about children under 16?

Finally, and the most important question, could anything else explain the results? This is known as the confounding variable question. Confounding variables are factors that affect both a factor and an outcome that is the result of a factor. For example, the lack of exercise in pregnant women leads to their weight gain. But a confounding variable here would be these women are carrying a fetus inside their bodies.

I think that the peer review process is a necessary part of successful scientific writings. It ensures that the content provided for the scientific community remains high quality toward learning and subsequent research. Thus, in this blog post, I will reflect on my feelings toward criticizing other people’s works as well as how I can apply peer review toward improving my own paper.

Peer review is a delicate task. It requires attention to detail as well as an ability to see the paper as a whole. Peer review is not about nitpicking other people’s mistakes but rather providing them with suggestions on how to improve. It is a process that requires positive remarks as well as constructive criticisms. Positive remarks are useful to point out what the author is good at. Regardless of how many improvements that a paper needs, there will always be something that the author does well.

There is a fine but very thin line between constructive criticisms and personal attacks toward the author. Constructive criticisms are about pointing out mistakes that could be detrimental to the author’s paper as well as ways to improve on those mistakes. Personal attacks are statements that are not constructive nor helpful toward both the author and the reviewer. The main goal of peer review is to improve, not to attack. Thus, the peer reviewer should solely focus on improving the paper rather than trying to attack the author’s standpoint on a certain topic.

Through the process of peer review, I learn to avoid mistakes that I might make while writing my own papers. I learn to see the positive sides of a paper regardless of the improvements that it needs. Thus, even after doing so many peer reviews, I think that having a bird-eye view of my paper will help me tremendously.

Peer review is the reading and critique of various aspects of a peer’s paper. Peer review is often conducted between two people of equal educational levels. Thus, the cornerstones of successful peer review are positive comments as well as constructive comments.

Firstly, the peer-review process starts with the analysis of the author’s thesis statement. The thesis statement provides the main idea that the author will focus on throughout the essay. Even in a refutation paper, the main thesis statement would serve as the main idea to refute a popular idea. The thesis statement is often found as the last sentence of the first paragraph. Next, the main ideas of each paragraph are taken into consideration. The peer will then tie back the main ideas of each paragraph to the thesis statement. The ideal essay would see the main ideas as closely as possible to support the thesis statement.

Secondly, the examination of evidence. Consistency is key. The evidence provides the author with information as well as statistics to back up their claims. The peer will examine the author’s evidence based on how relevant the evidence is to the theme of a paragraph. If the evidence is relevant, the peer will then examine the author’s interpretation of the evidence in the context of the paragraph. The peer will also analyze how the evidence supports or refute the thesis statement to make sure there would be no inconsistency.

Next, the peer will analyze the author’s language toward the intended audience. This is a more minor aspect of peer review. The level of scientific literacy differs between journals aimed toward scientists and articles in popular magazines. Thus, it is crucial for the peer to ensure that the language is appropriate toward the intended audience.

The final critique comes in the form of constructive comments on how the author could improve the paper. Perhaps it is readability, perhaps it is the transition between one paragraph to another. The peer’s role in this process is to ensure ideas from one paragraph connect to another to provide a comprehensive paper. Thus, this is also the part in which the peer also criticizes the paper as a whole.

Decreased exposure to microbes is associated with an increased likelihood that a child will develop allergies and asthma. Dysbiosis, a condition in which the human microflora suffers a loss of diversity or count of bacteria, is another consequence. Several illnesses in the GI tract are the result of dysbioses, such as Crohn’s disease and inflammatory bowel disease. Thus, it is crucial that behaviors that lead to decreased exposure to microbes are discussed. Hence, medical procedures that result in decreased exposure will not be addressed in this post.

First, the use of products that are harmful to microbes is perhaps the easiest to figure out. These products include antibiotics, disinfectants, and cleaning products. While the use of these products can be justified by hygiene and medical needs, it still leads to decreased exposure to microbes. Antibiotics are the most harmful of all. These medications eliminate both the good and the bad microbes, thus worsening dysbiosis. The use of these medications also possesses the risk of bacteria developing resistance.

Second, not allowing a child to interact with the world can also lead to dysbiosis. How often did you hear your mother said: “Stay home, don’t get some sunlight and playtime?” Playtime encourages interactions with other children and dirt, both possessing microbes. While we are in a pandemic, alternatives like backyard sports and such can be an option.

Third, the lack of breastfeeding can lead to decreased exposure to microbes for the infant. Breastmilk is not only nutritious for the infant but also contains microbes from the mother’s skin and milk. Furthermore, the mother’s behaviors during pregnancy can lead to decreased exposure to microbes to the fetus. Should the mother choose to smoke or consume alcohol or antibiotics during pregnancy, the fetus suffers. Not only in terms of prenatal illnesses but also reduced exposure to microbes.

Exposure to microbes from a young age, even bad microbes like Helicobacter pylori, is helpful toward the developmental health of a child. It is crucial in the sense that the child will grow up with a minimal amount of autoimmune diseases and dysbiosis.

The gut microbiota is crucial in the human body’s digestive process since these bacteria can break down molecules that our digestive organs cannot (1). Hence, the behaviors that we engage in our daily lives affect our gut microbiota. Thus, this post will discuss some behaviors that can dramatically alter the gut microbiota.

Some behaviors are good for the gut microbiota. For example, a diet rich in fibrous food is beneficial for the gut microbiota. The intake of probiotics is also good for the gut microbiota and companies making products like Yakult benefit from this finding. Some behaviors are devastating for the gut microbiota. The taking of antibiotics is a great example. Being in constant fatigue and a diet rich in sugar is also bad for the gut microbiota.

Physicians prescribe antibiotics for numerous infections, from a simple cold to food poisoning. However, the taking of antibiotics has a devastating effect on the gut microbiota (2). Antibiotics are like carpet bombing, destroying virtually anything in its paths. It does not matter whether it is the good or the bad bacteria that are being destroyed. The result is dysbiosis, a factor that contributes to Crohn’s disease and many more. An alternative for antibiotics would be phage therapy, in which bacteriophages are administered to combat infections. Since bacteriophages are specific to a certain kind of bacteria, they would not destroy the good bacteria.

Probiotics, like yogurt, and fermented food, like kimchi, are great for the gut microbiota (3). The inclusion of these items in the diet is beneficial for one’s overall health. Probiotics and fermented food are made using live bacteria; therefore, they help diversify and strengthen the gut microbiota. The result is the prevention of dysbiosis and better overall health outcomes. This scientific finding starts an industry of probiotic products.

Using tobacco products are devastating to the gut microbiota, according to numerous findings (4). Smoking reduces the diversity and strength of the gut microbiota. This results in dysbiosis and ultimately GI tract diseases, such as Crohn’s disease and ulcerative colitis. Smoking increases the risk of cancer, not just lung cancer, but also GI tract cancer, such as colorectal cancer (CRC). Smoking alters the cells and these cells can turn into cancer which can metastasize to other tissues in the body.

“You are what you eat.” It cannot be further than the truth that our diet affects the gut microbiota. Other behaviors can also influence the gut microbiota as well. Ultimately, it is up to us to take care of our gut microbiota since it has taken care of us since birth.

Cited Sources

1. Thursby E, Juge N. 2017. Introduction to the human gut microbiota. Biochem J. 474(11):1823-36.
2. Francino. 2016. Antibiotics and the Human Gut Microbiome: Dysbioses and Accumulation of Resistances. Microbiol. 6(1643). DOI: doi.org/10.3389/fmicb.2015.01543.
3. Zhang W, Li J, Lu S, Miao J, Zhang T, Qiang Y, Kong Y, Wang H, Gao T, Liu Y, Li X, Peng X, Chen X, Zhao X, Che J, Zhang L, Chen X, Zhang Q, Hu M, Li Q, Kan B. 2019. Gut microbiota community characteristics and disease-related microorganism pattern in a population of healthy Chinese people. Sci Rep. 9(1):1594.
4. Huang C, Shi G. 2019. Smoking and microbiome in oral, airway, gut and some systemic diseases. J Trnsl Med. 17(1):225.

Human papillomavirus (HPV) is a family of viruses that is specifically associated with anogenital, or related to the anus and genitals, cancers in humans (1). Many strains of HPV are strongly associated with cervical cancers. HPVs 16, 18, 31, and 45 account for 80% of the reported cases of cervical cancer. Undoubtedly, these strains must be the target of treatment before they can result in cancerous cell proliferation.

Biopsy analysis of cervical cancer samples is often most associated with HPVs 16 and 18; therefore, efforts have been made to ensure that these strains are included in the HPV vaccines. Thus, a new treatment should also focus on other high-risk strains, such as HPVs 31 and 45. Widespread screening for HPV should be conducted regularly to ensure that HPV infections are treated before oncogenes that have the potential to form cancers are activated. Strains that are classified as “potentially carcinogenic” should be studied more until there is concrete evidence that a considerable percentage of cervical cancers develop from these strains.

A good question to ask would be whether different strains of HPV share surface proteins. Research to study the viral capsids of HPV strains should be conducted to minimize the cost of vaccine research and increase vaccine efficacy.

Cited Sources

1. Sarid R, Gao SJ. 2011. Viruses and Human Cancer: From Detection to Causality. Cancer Lett 305(2): 218-27. DOI: 10.1016/j.canlet.2010.09.011.

In this blog post, I will discuss the non-infectious diseases that are influenced by microorganisms. Firstly, according to Bull and Plummer, a few of these diseases are Crohn’s disease (CD), obesity, type II diabetes, atopy, inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), ulcerative colitis (UC), etc. Secondly, disturbance in human microbiota is also correlated with atherosclerosis and liver diseases.

Based on these examples provided able, I see that microorganisms are crucial in keeping us healthy. The gut microbiota is partly responsible for the digestion of food. The bacteria in the gut microbiota provide the metabolism of nutrients that the digestive organs alone could not complete. Therefore, any disturbance in the gut microbiota is the root of the many diseases of the digestive organs. This disturbance shows the most effects on the gastrointestinal tract, with Crohn’s disease being the prime example. Crohn’s disease, as pointed out by Pascal et al., is an inflammatory bowel disease subtype, which is caused by imbalanced gut microbiota. An analysis of people with Crohn’s disease shows that there are less diversity and stability in these people compared to their unaffected peers.

In addition, I find it surprising that this disturbance also affects the circulatory system. Atherosclerosis is a disease caused by plaque buildups in the arteries. These buildups block blood circulation and create thrombi or blood clots. The American Heart Association designates diabetes and elevated blood cholesterol levels as risks for atherosclerosis. I can see that metabolism issues, which are influenced by the gut microbiota, could cause further complications with other organs. Atherosclerosis can lead to heart diseases and death; therefore, the human microbiota also serves a crucial function in keeping us alive.

In conclusion, it is not just the infectious diseases that we have to care about. The small changes within our microbiota could very much be influential to our general health and well-being; and therefore, we must take care of them for the sake of our own health.

Welcome to Hung’s blog for Microbial Influences on Human Health. In this blog, I will discuss the various ways that microorganisms affect our individual and community health. Comments are welcomed and greatly appreciated.