A2: Microbes in the News (#2)

Bacteria in probiotics can evolve in your gut and turn nasty, study shows  (The Independent)

Link: https://www.independent.co.uk/news/health/probiotic-bacteria-gut-health-ibs-bowels-a8840636.html

Summary:  This article talks about a study performed at the University of Washington in Missouri where a probiotic evolved to attack the protective coating of the intestine in the mice they tested. Unhealthy mice with low gut microbial diversity were more likely to develop an evolved strain of the  E. coli Nissle bacteria that was used in the probiotic they studied. According to the researchers, their findings have implications for the development of safer probiotics in the future.

Connections: This article is very relevant to the human microbiome section that we covered in class. It involves the gut microbiome and the ways it can be more or less healthy, and more or less diverse. I think the way microbes can change and evolve right under our noses is fascinating!

Critical analysis: This was certainly an interesting piece and the writing style flowed well. However, this study is only one of many and might mislead readers to think that all probiotics can “turn bad.’ It could also be confusing to the regular reader, because the wording of the article makes it seem like probiotics are drugs that can change inside your body. Of course we all know that probiotics are made up of living bacterial cells that are supposed to help enhance the diversity of your gut microbiome. It was also unclear whether the  E. coli strain always evolved in a negative direction or if it was simply more prone to evolve in an unhealthy gut microbiome (toward good or bad characteristics, we don’t know). Overall, this was a well-written article, but I think the writer conveyed what he wanted the readers to believe and not necessarily the actual truth of the study.

Question:  What were the exact parameters of the evolution of  E. coli Nissle observed in this study?

“Does the Gut Microbiome Ever Fully Recover From Antibiotics?’



“Does the Gut Microbiome Ever Fully Recover From Antibiotics?’ Richard Klasco, M.D.

New York Times. December 21, 2018.


Summary: Although most microbes in the “gut’ grow back quickly and normally after stopping the use of antibiotics, there are some which take much longer to grow back, and some which may never grow to the same population density they once were.

This may have unknown effects on the body, but may contribute to certain health ailments, including inflammatory bowel disease and heart disease.


Connection: While microbes are generally thought to be fast growing, we have learned that some grow quite slowly, depending on their metabolism and physiology. If a microbe takes a long time to reach maximum population density, wiping them all out with an antimicrobial may have long term effects that cannot be easily undone by simply ceasing the use of the drug.


Critical Analysis: Without more knowledge on which specific species are affected long term by the use of antibiotics, it is hard to understand the full implications of the research. The human microbiome is a field with increasing focus and attention recently, and understanding the long term effects of some of these antibiotics may contribute to the development of less harmful medications which could help with the ever-growing problem of microbial antibiotic resistance.


Question: Could the use of certain probiotics help restore the population of some of these microbes in the gut following a course of antibiotics?

A2:Microbes in the News

Title:  Specific Gut Microbes Linked With Depression: Study

Source:  The Scientist

Author:  Ashley Yeager

Date Published:  February 4, 2019

Article Link:  https://www.the-scientist.com/news-opinion/specific-gut-microbes-linked-with-depression–study-65427

Summary:  This is a small article that nicely states some findings from a project called the Flemish Gut Flora project. The results seem to conclude that two types of bacteria, in the gut are depleted in people who suffer from depression the bacteria, Coprococcus and Dialister, were found to be two of the main bacteria that were missing in those with depression. The article states if the results are further confirmed (as this is one of the first major studies and findings of its kind) it could lead to a plethora of information about the gut-brain connection and further provide new solutions for mental illness. Concluding this article are a few different statements from different scientists, both involved in the study and not, on its importance as being the first step in discovering the major role the microbiome plays in health and disease.

Connections:  This article connects very closely to what we’ve been talking about in class in the sense that an argument could be made for microbes ruling the world. If this study is further confirmed it would be a stepping stone to realizing that almost all of the problems people have are on a microbe level. Every decision people make, that changes the world, is influenced by their mental clarity and how they are feeling. Therefore, I would say microbes do rule the world, as they influence every aspect of the people, animals, plants and everything that make up the world.

Critical Analysis: I found this article interesting because of the implications it was hinting towards. Saying that this was the first real stab at understanding a huge unknown microbiome and that it could be a tool to cure mental illness. I had heard this theory of the gut biome having more of an influence on the entire body before, but it was very interesting to see an article talking about a large scale study that had been done. I believe the story was accurate scientifically, it was a smaller article, but all the information on the study and the results can be found quite easily. It was written in a fairly easy to read way, where anyone in the general public could understand the general idea that the gut biome plays a role in depression. So I think it does a good job communicating science to the public, however I will say it definitely is trying to paint a much bigger picture for people to grasp on. While this research was a big project, it is one of the first and much more needs to be learned about the gut biome before one can truly say a link for depression is only these two gut bacteria.

Question: Do you think one-day, microbial gut ‘supplements’ could be a viable cure to mental illness or other disease?

A2: Microbes in the News

Article and Link: The article I found was published in the New York Times by Richard Klasco, M.D. on December 21, 2018 titled Does the Gut Microbiome Ever Fully Recover From Antibiotics. The article can be found here but just a warning; The New York Times only allows so many article views per day before you have to pay for them.

Summary: The overview of the article is that studies are reviewing how the gut microbiome recovers from a course of antibiotics and questioning if the microbiome ever fully recovers to the same flora as prior to antibiotic treatment. The article gives basic information of the function of the microbiome in regards to human health and how the usage of antibiotic treatment indiscriminately kills bacteria regardless of being natural flora are harmful; it also has links to five different studies involving the microbiome and human health. The linked studies reviewed infant antibiotic treatment and breastfeeding, intestinal metabolism, effects of antibiotics on the gut microbiome analyzed by sequencing, and the microbiome showing incomplete recovery from repeated antibiotic treatment. The information being presented is stating that there is an increased risk for chronic health diseases with the use of repeated antibiotic treatments because the natural flora of the gut might not fully recover.

Connections: I will edit this post to add a question once we have progressed in our course.

Critical analysis: I found the study that analyzed infant gut microbiome, breastfeeding, and antibiotic usage very interesting. I’m glad that this article posted the link to PubMed so I was able to read the abstract. From the basic information in the article (without reading all the linked studies) I learned that there has been links between a disrupted gut microbiome and heart disease, obesity, asthma, and inflammatory bowel syndrome; I was surprised about the asthma and heart disease. I found that the article made some very bold statements that I could not directly find in the abstracts of linked studies but would be interesting in doing a bit more research.

Question: Given that we know that antibiotics are necessary in some cases but bacteria are increasingly becoming antibiotic resistant, I wonder if it more stress on prevention of unnecessary antibiotic usage should be given to the public. If the gut microbiome has such a difficult time recovering fully from antibiotic treatment should more research be conducted to alternatives to restoring proper function.