Writing Exercise #9

cleaner water:

-Although cleaner water normally sounds like a good thing, the ingestion of water from rivers and wells that indigenous people consumed had many more microbes from the environment. The water consumes now is so highly processed and removed of microbes we have much less exposure.

Smaller families:

-With couples choosing to produce less offspring for financial purposes, there are fewer microbes that can be exposed to people at younger ages. As siblings may live in the same environment, they are not glued to each other and tend to make different friends, hang out in different places, and do different activities. This increases the exposure of various microbes to individuals from their siblings who experience different environments. The exchange of microbes between siblings is a factor.

Born via Cesarian section:

-Being delivered by c-section changes what microbes an individual is immediately exposed to at birth. It has been shown that vaginal bacteria are very beneficial to infant development. People who are born via c-section do not get exposed to this beneficial bacteria and are instead immediately exposed to skin bacteria. By missing out on being colonized by vaginal bacteria, those individuals miss out on the health benefits that come with them.

Antibiotic exposure:

Taking many antibiotics as a child or infant changes the stable structure of microbial communities. They can kill healthy bacteria that are used in immune defense or metabolism and have co-existed with humans for thousands of years, such as H.pylori. The use of antibiotics selectively permits certain microbes to inhabit while others cannot, which can last for years after ceasing the use of the antibiotic.

Decline in breastfeeding:

-The decline in breastfeeding and increase in formula feeding has decreased microbe exposure. The oral microbiome of infants will have greater colonization of microbes from the breast and from the milk that is beneficial, while formula infants will not. Additionally, the gut microbiome is further matured in infants who drink breast milk and need to breakdown the sugars/fats that are present in breast milk.

Playing outside as a child:

-Children who play outside are exposed to many more microbes than those who stay inside. Acts such as eating dirt as a child can expose an individual to many microbes as there is a lot in soil. Additionally, playing with other children outside can increase the likelihood of exchanging microbes and being exposed to germs from the other child’s environment.


Writing Exercise #8

  1. There have been many things that have been very interesting to me in my time of this course. The first of them being how microbes of the gut have influence over obesity. Another one is how the dysbiosis of microbiota cause/have heavy negative influence over gastrointestinal diseases and cancer but probiotics are able to restore microbial communities and have positive impacts on diseases. The way probiotics and antibiotics are heavy influencers over gut microbiota, with antibiotics actually having a more negative effect than positive. The way microbes influence our metabolism has always amazed me thus far and I am most impressed by how the microbes in obese people are different than in healthy people and break down molecules differently.

3. The influence of microbes over obesity has been particularly interesting in this class. Some experiments have shown that the fecal transplant of obese people’s microbes into germ free mice has had increased adiposity when compared to mice inoculated with lean persons feces. The microbial community of obese people are usually at a dysbiosis and don’t have microbes that can metabolize certain compounds that are important in preventing adiposity development. Lean microbial communities have microbes that produce short chain fatty acids and metabolize simple carbohydrates and are insulin sensitive while many bacteria found in obese individuals are insulin resistant and do not promote the uptake of glucose like they do in lean individuals.

4. To begin preparation for my final essay, I will start to research and look for articles about microbes influence over obesity. I will find articles that explain the dysbiosis prevalent in obese individuals and how the microbes or lack of microbes affect the molecules metabolized by an individual. I also want to find out how the microbes of obese individuals affect their insulin sensitivity. Lastly, I will explore articles on how microbes affect inflammation in obese individuals and the consequences of that induced inflammation.


Writing Exercise #7

Diet of the mother:

-The diet of the mother during gestation and before pregnancy showed changes in microbial composition in their feces. Obese pregnant women showed significantly more Bacteroides and Staphylococcus in their feces in comparison with normal weight pregnant women. A study of diet induced obese rats revealed that when these rats were fed oligofructose prebitoics during pregnancy and lactation, the cecal microbiome of the offspring was altered. The result was that it prevented increased adiposity in the both the dams and offspring. This implied an early maternal effect on offspring microbiota


-Antibiotics given to pregnant mice showed a few negative effects such as decreased bacterial diversity. Researchers also observed that maternal antibiotic administration during pregnancy decrease immune response in the infant mice. Lastly, non-absorable antibiotics given to pregnant maternal mice altered offspring behavior, showing decreased locomotor activity and lower levels of exploratory activity.

Mode of delivery

The type of delivery seems to have an affect on the bacteria that infants are exposed and colonized with when they are first born. The two modes discussed are vaginal vs. Cesarean section birth and how they affect the gut microbiota of an infant. The infants delivered via the vagina displayed colonization of vaginal and maternal gut bacteria in their gut. Infants who were born via C-section were colonized by bacteria that resembled skin and oral microbiota. This is interesting because the microbiome of c-section infants contained a higher proportion of bacterial anti-biotic resistant genes than vaginally delivered infants. It has been suggested that disruption of vaginal bacteria transmission due to C-section can cause long-term medical implications.

Breast Feeding vs Formula:

-Breast milk contains sugars that cannot be digested by infants so bacteria such as Bifidobacterium, Lactobacillus, and Bacteroides help break down the polysaccharides to be used as an energy source. This gives them an advantage over competing bacteria. As a result Bifidobacterium are most abundant in breast-fed infants while Enterococci and Clostridia are dominant in formula fed infants. Three month old breast fed infants had oral bacteria that contained antimicrobial properties that were not found in formula fed infants.


Writing Exercise #6

My personal philosophy about taking antibiotics is to only take them when they are prescribed to me by a physician and to follow the directions the pharmacist gives me when I pick up the prescription. I don’t usually go to the doctor when I am sick as I just try and strengthen my immune system to fight the sickness and overcome it, instead of just running to the doctor every time so they can give me me antibiotics to feel better. I believe I formed this philosophy because I always assumed the doctors knew what they were doing and would only prescribe antibiotics if they deemed it necessary. I also am pre-pharmacy and have always been interested in that field, so I also trust that the pharmacist’s extensive knowledge about the drugs and their directions are worthy following down to the tee. I feel like I always trusted these healthcare providers because of their credentials, knowing that they both have doctorates in their respective professions gave me a perception that they are always doing the right thing. The older I have got and the more I have educated myself I have found that not to be true, as physicians and pharmacists alike can make mistakes. In the case of antibiotics, it seems like doctors largely over-prescribe these drugs and it is causing a large problem of antibiotic resistance which could easily be avoided with other treatment options.


Writing Exercise #5

Generally, when I am making a conscious decision about what food I am going to consume I generally try and eat the healthier option. When I say healthy I mean, staying away from very greasy meals or meals loaded with carbohydrates. I try and eat as much protein as possible, such as chicken, as well as as many vegetables as possible with my meals. I generally try and monitor my carbohydrate intake as I don’t find too much nutritional value in just eating a large amount of carbs in order to be full. I always try and include vegetables because I believe they are a great source of vitamins and provide immune system boost as well as very supportive of other physiological functions. When I do choose to eat out I generally try and eat sandwiches from places such as Jimmy Johns or grocery stores, staying away from just large amounts of greasy foods like hamburgers, pizzas, and fried food. I think that these choices have a positive impact on the microbial community in my gut. Eating less fast food and eating more protein and vegetables promotes the growth of healthy bacteria and bacteria that can break down these healthy foods. Some of my non-intentional decisions may have negative affects on my microbial community though. I sometimes get cravings for sweets or chocolate after a nice meal and that leads me to search for and eat foods loaded with sugar on occasion even though I know I shouldn’t be eating them. This could be promoting the growth of unhealthy and possibly virulent bacteria that are not good for my stomach. Overall, I believe I keep a good balance of foods in my diet that promote an overall healthy gut microbiome.


Writing Exercise #4

Cheng-Yen Kao, Bor-Shyang Sheu, and Jiunn-Jong Wu are professors at National Cheng Kung University in Tainan, Taiwan, who wrote a review article titled, “Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis” where they highlight the key findings of H. pylori virulence factors reported over the past 20 years. The authors state the four general steps that occur with H. pylori infection, and then precede to describe these steps in great detail, highlighting all of the interactions between the stomach and bacteria. The purpose of this review article is to breakdown the exact virulent mechanisms employed by this bacteria in the human gut down to the enzymatic level in order to combine all research done on the infection of H. pylori. The intended audience of Kao, Sheu, and Wu is that of scientific scholars in microbiology, that are looking for a detailed summary on the virulence factors involved in H. pylori infection.