User talk:GeorgeVKach/sandbox

Assignment 1

The peptidoglycan article does a good job of providing a brief, well structured gist about peptidoglycan.

The article material is relevant to the topic: it introduces what peptidoglycan is, its structure, biosynthesis, and role, all of which is pertinent. The article does a good job of presenting information in an objective and neutral language free of value statements, and most claims are followed by appropriate citations. However, in the first paragraph, the last claim does not have an obvious citation, and I could not verify the claim that there is a “common misconception”.

The sources the authors use are largely appropriate, and seem to be free of biases. However, the first reference is a website whose authors and affiliations are unclear, which made me question it a bit. Furthermore, the first few sentences of the article very closely mirror the source that is cited; although it is possible that there are limited ways to introduce what peptidoglycan is. The subsequent references are reliable, and include journal articles (such as Nature), an encyclopedia, and a textbook.

There is no overt indication that views are either over represented, or underrepresented. However, the article is a bit short, which leaves us wanting. For example, peptidoglycan is commonly talked about in the context of gram-positive versus gram-negative taxonomy. However, this style of classification is problematic, which is worth discussing in the article.

Finally, the talk page is sparsely populated, with only 2 entries, and no major back and forths. GeorgeVKach (talk) 18:02, 17 September 2017 (UTC)

Assignment 2

The gut flora topic is of high notability: there is a significant amount of coverage on the topic, and the present Wikipedia article has numerous reliable references including textbooks and research articles from reputable journals (including The Lancet and Nature, which are known for their stringent standards and high impact factor). Gut flora is an area of vibrant research independent of the subject.

However, there is some information in the Wikipedia article that is out of date and which can be expanded upon. The “Acquisition of gut flora in human infants” subheading is presently surprisingly short. Furthermore, the present entry states that the fetal gastrointestinal (GI) tract is considered sterile, and only briefly mentions that some microbial colonization can occur. This statement is a bit out of date: there is growing evidence that the uterine environment is not sterile.

Several studies have demonstrated the presence of bacteria in the amniotic fluid and placenta, as well as in the meconium of babies born by sterile cesarean section. Rat studies have also been used to confirm that mothers can transmit bacteria to children: in one study, a culture of bacteria were administered orally to a pregnant dam, and then detected in the offspring. This has many implications, one of which is the fact that if the mothers microbiome were to change, she could pass on those changes her offspring. For example, a high fat maternal diet leads to an altered offspring gut microbiome in primates, an effect also observed in human babies born to mothers consuming a high fat diet.

While the actual mechanism behind this transfer of dysbiosis is not yet clear, this contrasts with what the present Wikipedia article suggests, and is therefore worth mentioning.

I will be updating and expanding the article to reflect more closely the current state of knowledge. GeorgeVKach (talk) 03:31, 27 September 2017 (UTC)

George's peer review
Highlights: Added content expanded on the knowledge deficit and possible origins of the gut microbiome in infants, and included new/current research with supporting detail, consistent with the stated goal in the student’s assignment 2. Furthermore, the references were relevant, included neutral views on the topic, and were from reliable journals. However, there are several sentences attributed to a single source, but these were mostly artifacts from the original article. A suggestion would be to revise these sentences to include other references. The addition of the rodent study, findings, and conclusions really complemented the article, and demonstrated the possible internal mechanisms of flora acquisition (i.e. amniotic fluid or placental transfer), which were not included previously. Interpretations of one study’s outstanding questions (Box 1) were supported; however, the findings of orally administered bacteria in pregnant mice found in the offspring should also mention transmission between the digestive tract and amniotic fluid via the blood stream to better connect previous ideas.

Improvements: Lead content is verbose and can be written more precisely – consider rephrasing or removing the first three sentences of the second paragraph. What is the “traditional view” referring to, and who is challenging it? The possible origins of bacterial transmission can be grouped together in the third paragraph (siblings were mentioned twice), leaving the last paragraph to expand upon microbiome regulation. However, the last sentence implies caesarean sections require microbiome restoration, but it was not mentioned in the article that this method of delivery was detrimental to the gut flora. Mentioning the increased risk of diseases, potential adverse affects on the gut microbiota, and overall health detriments associated with cesarean sections would demonstrate the importance of the gut microbiome, especially as cesarean sections are becoming more commonplace. Small errors in grammar and spelling have been indicated in bold below.

ORIGINAL ARTICLE (do not count towards word count):

The establishment of a gut flora is crucial to the health of an adult, as well the functioning of the gastrointestinal tract. In humans, a gut flora similar to an adult's is formed within one to two years of birth.

The traditional view of the gastrointestinal tract of a normal fetus is that it is sterile. However, this view has been challenged in the past few years. Multiple lines of evidence have begun to emerge that suggest there may be bacteria in the intrauterine environment. In humans, research has shown that microbial colonization may occur in the fetus with one study showing Lactobacillus and Bifidobacterium species were present in placental biopsies. Several rodent studies have demonstrated the presence of bacteria in the amniotic fluid and placenta, as well as in the meconium of babies born by sterile cesarean section'''. (Period added)''' In another study, researchers administered a culture of bacteria orally to a pregnant dam, and detected the bacteria in the offspring. However, researchers caution that the source of these intrauterine bacteria, whether they are alive, and their role, is not yet understood. (last sentence is phrased awkwardly)

During birth and rapidly thereafter, bacteria from the mother and the surrounding environment colonize the infant's gut. The exact sources of bacteria is not fully understood, but may include the birth canal, other people (parents, siblings, hospital workers), breastmilk, food, and the general environment with which the infant interacts. However, as of 2013, it remains unclear whether most of (remove 'of') colonizing arises (Added 's') from the mother or not. Infants born by caesarean section may also be exposed to their mothers' microflora, but the initial exposure is most likely to be from the surrounding environment such as the air, other infants, and the nursing staff, which serve as vectors for transfer.

During the first year of life, the composition of the gut flora is generally simple and it (remove 'it') changes a great deal with time and is not the same across individuals.[1] The initial bacterial population are generally facultative anaerobic organisms; investigators believe that these initial colonizers decrease the oxygen concentration in the gut, which in turn allows purely (change to 'obligately') anaerobic bacteria like Bacteroides, Actinobacteria, and Firmicutes to become established and thrive.[1] Breast-fed babies become dominated by bifidobacteria, possibly due to the contents of bifidobacterial growth factors in breast milk, and by the fact that breast milk carries prebiotic components, allowing for healthy bacterial growth.[3][4][5] In contrast, the microbiota of formula-fed infants is more diverse, with high numbers of Enterobacteriaceae, enterococci, bifidobacteria, Bacteroides, and clostridia.[6]

Several other factors may influence the colonization pattern and the kind of bacteria that establish the gut flora. These factors include the delivery mode (vaginal versus cesarean section), being held in a neonatal intensive care unit, sanitary conditions, as well as presence of siblings in the family.[13] Children treated with antibiotics have less stable, and less diverse floral communities.[14] Various methods of microbiome restoration after cesarean section, antibiotics, or formula feeding are being explored, and typically involve exposing the infant to maternal vaginal contents, and oral probiotics.[15]

Kevinxchan (talk) 19:47, 8 November 2017 (UTC)