Writing Exercise #3

Prompt: Brainstorm a list of behaviors that an individual could engage in that could cause changes to their gut microbial community. Pick 3 specificbehaviors from you list. For each, discuss how that behavior could change the microbial community and the potential health impacts (beneficial, detrimental, neutral) that could result for the individual’s health.

  • Various behaviors can cause changes to gut microbial communities. Some of these include: aging, antibiotic use, diet, environmental factors, and taking pre/probiotics
    • Taking prebiotics/probiotics
      • Taking prebiotics and probiotics have gained popularity over time. Prebiotics can promote growth of commensals and have potential to improve GI health. Probiotics have led to promising results as far as restoring the gut microbiota and treatment of intestinal disorders. Prebiotics and probiotics support the body in building and maintaining healthy bacterial colonies which in turn support gut health and can also aid in digestion. They help promote the growth of beneficial bacteria. Taking prebiotics and probiotics have beneficial impacts on health.
    • Antibiotic use
      • Antibiotic use can have potentially damaging effects to gut microbial communities. Although antibiotic use can be beneficial in curing infection, it can also have damaging effects in regards to the gut microbial community. Antibiotic use can lead to dysbiosis as they not only act on the bacteria that cause infection but also the resident microbiota that can be healthy in our systems. Although some resident microbiota can recover after antibiotic use, many cannot.
      • Antibiotic resistance also plays a role in the effect on gut microbial communities, as many of the harmful bacteria that cause infection find ways to evade antibiotic effects and in turn become stronger and more pathogenic. 
      • Overall, antibiotic use has detrimental impacts on health. Taking less antibiotics can help in limiting the detrimental health impacts that may occur.
    • Diet
      • Diet is a major contributor to changes in gut microbial communities. Maintaining a varied diet has beneficial impacts on health and gut microbial communities. Maintaining healthy proportions of fruits and vegetables as well as all other food groups ensures that you provide your gut’s microbial communities with beneficial resources for their survival. Diversity of gut microbial communities is typically associated with more stable, resilient communities and ensuring a diverse, healthy diet can promote the growth of diverse ranges of healthy microbes in the gut. 

Writing Exercise #2

As a healthcare professional, a colleague asks your opinion as to which HPV strains should be covered in a new treatment. Based on your reading from the Sarid and Gao 2011 article, what is your recommendation, and when should the treatment be administered? What evidence supports your opinion?

Human papillomavirus (HPV) is a very common virus that can lead to various types of cancers. According to the Sarid and Gao article, HPV is now recognized as the virus responsible for causing essentially all cases of cervical cancer in women, with a higher risk associated with certain strains. Today, over 100 types of HPV have been identified (1).

Although developing a vaccine for every strain of HPV would be an incredible advancement in the field of oncology, it is simply unplausible. The process of developing a vaccine for every HPV strain would take a lot of time, and a lot of money. Findings show that the cost of developing a vaccine from preclinical trials through to the end of phase 2a ranges from 31-68 million US dollars, and that is assuming no risk of failure (2). Cancerous cells are constantly (and rapidly) evolving and developing new abilities in order to evade detection. It would be nearly impossible to develop successful vaccines for every strain. The cost of vaccine development for every strain of HPV would also likely come at a great price to the public, therefore rendering it unaccessible to many individuals in general.

There are 12 different HPVs, and four of them, including HPVs 16, 18, 31 and 45 account for about 80% of cervical cancer. The remaining HPV types are also associated with cervical cancer and several have been classified as “probably carcinogenic to humans”, however, the four mentioned above are considered high-risk HPVs. Vaccines currently exist for HPV16 and HPV18, therefore, my recommendation would be to develop a vaccine for the other two high-risk HPVs, HPV31 and HPV45.

Because human papillomavirus is a sexually transmitted infection, the vaccine should be given to individuals before they have sexual contact with others and are exposed to HPV. I would recommend giving the vaccine around age 11 to begin protecting against HPV prior to possible exposure.


Sarid R, Shou-Jiang G. 2011. Viruses and Human Cancer: From Detection to Causality. Cancer Lett 305(2):218-227.

Gouglas D, Le T, Henderson K, Kaloudis A, Danielsen T, Hammersland N, Robinson J, Heaton P, Rottingen J. 2018. Estimating the cost of vaccine development against epidemic infectious diseases: a cost minimisation study. Lancet Glob Health 6:e1386-1396. DOI: 10.1016/S2214-109X(18)30346-2


Writing Exercise #1

The first important aspect to focus on here is non-infectious diseases, which are diseases that are not contagious and are not caused by pathogens. These diseases are often caused by various lifestyle factors, mutations in genes, or toxins in the environment. The non-infectious diseases that come to my mind and may be modulated by microbes include cancer, diabetes, cardiovascular disease, asthma, and Alzheimer’s disease.