User talk:Cheng Xi/sandbox

Critique of Peptidoglycan

This article cites through reliable and reputable sources but I don't think the author uses enough sources. The author does loosely follow the general guideline of a minimum of one citation per paragraph however there are many statements of fact in the article that do not have a citation attributed to it. For example, this can be seen in the last sentence of the first paragraph, the whole first paragraph in the Structure subheading, and the third paragraph of the Biosynthesis subheading. The author should have a citation for every statement that is not common knowledge. The author maintains a neutral stance throughout the whole article and for the most part is unbiased. However, he does use one source 9 times throughout the article which may not be ideal as it suggests bias towards a certain source although probably unintentional. The hyperlinks for all the sources work properly except for textbooks which are probably behind paywalls. In terms of content, I think the author does a good job of representing the core functions of peptidoglycan but limits the article to only the biology of peptidoglycan and not much of the application of it by humans such as gram stains which I think are extremely important. There are also some problems with the lead. The training module recommends the lead to be concise to the main definition and function of peptidoglycan. However, there is mention of binary fission and gram stains which I think would be better as subheadings. The author does hyperlink to related topics which is useful for learning about peptidoglycan.

Cheng Xi (talk) 23:29, 12 September 2017 (UTC)

MICB 322: Assignment 2
The Wikipedia source that I would like to edit is Human microbiota. The subject of human microbiota has become highly notable since discovering the role of microbiota in causing human disease. Since then, more and more knowledge has been gained on the topic with discoveries of microbiota being found in places thought to be previously sterile. It was previously thought that the uterus and placenta were sterile but it has been found that they are indeed colonized by a wide array of microbiota as well. In 2017 alone, a quick search on Google Scholar showed that over 8200 articles have been published relating to the human microbiota.

The Wikipedia article on human microbiota is detailed in that it covers a broad range of subtopics. However, I feel like the subtopics do not go into enough depth. There are several sections that I think lack depth such as microbiota in the placenta and gut. Although the placental microbiome is still a new area of research, there is no mention of the current research that has been done on the topic. Currently, researchers have found that there is a direct correlation between pre-term births and gestational diabetes with the types of bacteria (proteobacteria, firmicutes, etc) found in the placenta. Specifically, researchers have a found that pregnant women with gestational diabetes had an increase in placental Firmicutes and Actinobacteria and a decrease in Proteobacteria.

I also believe that the gut section needs improvement as the information discussed is not reflective of the overall research done on gut microbiota. The section only mentions the mutualistic nature of gut flora through its help in digestion and its use as a treatment to help with anxiety, depression, etc. It makes almost no mention of some of the more harmful effects of gut microbiota. Imbalances in the gut microbiome has been known for some time to cause obesity and metabolic syndrome   but the subsection makes no mention of it. As well, the composition of the gut microbiota has been found to be linked to stomach ulcers, inflammatory bowel disease and irritable bowel syndrome.

Cheng Xi (talk) 01:21, 24 September 2017 (UTC)

Cheng Xi's Peer Review
I went through the article and made some general edits (only to the sections you changed). @JoeHo, please don't mark this, this is not part of my review. CodeSwitch (talk) 20:53, 3 November 2017 (UTC)

Edits: In humans, the composition of the gut microbiota is largely influenced from the bacteria that a newborn is exposed to during birth[8]. Birth by Cesarean section instead of vaginal delivery also influences the gut’s microbial composition. Babies born through the vaginal canal had non-pathogenic, beneficial gut microbiota similar to those found in the mother[9]. However, the gut microbiota of babies delivered by a C-section harbored more pathogenic bacteria such as Escherichia coli and Staphylococcus and it took longer to develop non-pathogenic, beneficial gut microbiota.

However, changes in the composition of the gut microbiota have also been correlated to harmful health effects. In a study done by Gusso et al., it was found that the gut microbiota of obese individuals had more Firmicutes and less Bacteroidetes than healthy individuals[11]. Furthermore, they determined that this was a unidirectional relationship where the composition of gut microbiota caused obesity. They determined this by transplanting the gut microbiota of obese mice into lean mice and found that after two weeks the transplanted mice had gained significantly more fat than the non-transplanted mice, indicating that the microbiota transplant had caused the excess fat accumulation[12].The role of the gut microbiota in causing obesity has also been confirmed by several other independent studies[13][14][15].

End of general edits.

Critique begins here Your additions add significant knowledge by citing pertinent research that supports the article’s claims. The effects of the gut microbiota on obesity is an important area of research and very relevant to the gut microbiota section. Your writing is neutral and well communicated to the average reader.

Your additions might benefit from better explanation of results. The study referenced as Musso et al. is a review about two studies done by Gordon et al. The first study determined that lean germ-free(GF) mice gained less total body fat than lean control (normalized microbiota) mice and that colonization of the former by bacteria from the latter caused the former to gain weight. The second study transplanted lean GF mice with microorganisms from either lean or diet-induced obese(DIO) mice. GF mice which hosted the microbes from the DIO mice had higher total body fat despite eating the same diet. This was postulated to be due to differences in calorie extraction from food. Your description seems to suggest that transferring bacteria from the gut microbiota of obese mice into that of lean mice produces an obese phenotype. I suggest using descriptors/acronyms such as “germ-free(GF)” and “diet-induced obesity(DIO)” to improve reader comprehension.

Another important consideration is your use of primary vs secondary information. I checked all the references and they’re all reviews. None are the original studies. Having secondary articles is okay in some cases, however when discussing the results of a study, it is preferable to reference the group that did the study. Same problem with [13][14][15].

Lastly, your structure is excellent, however your writing could still be more concise. One pertinent example is your introductory sentence. You use several terms twice, e.g. “during birth”, “newborn” and “gut microbiota/flora”. Careful rephrasing (see my edits) could reduce extraneous words, improve concision and help capture the reader’s interest. CodeSwitch (talk) 00:10, 6 November 2017 (UTC)