There has
been a lot of research and a lot of claims about the ideas surrounding the
hygiene theory, which has been a theory for over a decade. The hygiene theory is a theory that suggests
that the more exposure a baby and child has to microorganisms the less risk
that the individual will suffer from autoimmune disease. Now new data suggests that early exposure to
antibiotics in babies and young children can lead to food allergies.
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GEOFF TOMPKINSON / SCIENCE PHOTO LIBRARY / Universal Images Group
Rights Managed / For Education Use Only/ Retrieved from the web Sept 2016/http://quest.eb.com.ezproxy.liberty.edu/search/cephalosporin/1/132_1263451/Orally-active-antibacterial-Cephalosporins
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Read this article and comment about the theory regarding how antibiotic use
early in life could contribute to food allergy later in life.
Also comment
on how exposure to microbes early in life helps the body and immune system
become muted towards ingested food.
Comment
on the specialized immune system which interfaces with the digestive system.
How is it different from other parts of the immune system?
Also please add a citation of an article which helped you with your research on this topic.
Due October 10
According to the article provided antibiotics alter the composition of the gut flora, or microbiome. The Univ. of South Carolina has studied this and hypothesized that the microbes in a child are actually important in developing the immunity system. Because, however, antibiotics kill bacteria including those in the digestive tract, they would effectively lead to development of food allergies.
ReplyDeleteExposure to microbes in turn mute the immune system to ingested foods. This means that exposure to bacteria actually build immunity. Stanford Medicine has an article (https://med.stanford.edu/news/all-news/2013/02/immune-systems-of-healthy-adults-remember-germs-to-which-theyve-never-been-exposed-stanford-study-finds.html) that explains that this is because of our CD4 cells. CD4 cells circulate in blood and lymph to kickstart the immune system when they find a pathogen. The reason why they are involved in the building of the immune system is because they acquire memory of all the pathogens they face. Therefore, more exposure to microbes is more memory of pathogens. This idea is supported by this Johns Hopkins article: http://www.hopkinsmedicine.org/news/media/releases/newborns_exposed_to_dirt_dander_and_germs_may_have_lower_allergy_and_asthma_risk
The mucosal immune system interfaces with the digestive tract. This is different than other parts of the immune system because it avoids an immune response from food antigens while also killing pathogens in the gut. It also involves millions of commensal bacteria which protect the gut from pathogens by occupying those ecological niches (https://www.ncbi.nlm.nih.gov/books/NBK27169/)
I did not come across CD4 cells in my research of this topic, but I am glad you did because that is very interesting. It is amazing to discover these different aspects of the immune system that then directly relate to the gastrointestinal system and how our bodies react to what we ingest. It is also fascinating how those millions of commensal bacteria you mentioned work to protect the gut. This is just another aspect that proves we are fearfully and wonderfully made.
DeleteI agree with Sam, Sheri, on how I missed CD4 cells but am glad you did. I think it appropriate to call the immune system almost a type of memory system and now I know the specific cells that contribute to its unique ability to memorize.
DeleteThe research done by the University of South Carolina supports the theory that using antibiotics in early childhood will cause allergies later in life. This is because antibiotics change the gut flora which then disrupts the body's ability to tolerate different foreign proteins like those in food. It makes sense since the bacteria in the digestive tract help the body to breakdown and digest certain foods while antibiotics kill bacteria. (The CDC explained how antibiotics work in this page http://www.cdc.gov/features/getsmart/ the University of Rochester Medical Center Rochester also helped clarify what bacteria are beneficial and why they are in the body https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90&ContentID=P02019) Having more helpful bacteria in the body will allow the body to not treat foods as foreign and helps the body to digest what comes in. In addition, further research was done to show that the administration of probiotics after birth even reduced the frequency of food allergies (http://www.karger.com/Article/Abstract/71488).
ReplyDeleteTherefore, we see that exposure to microbes early in life helps the body and immune system become muted towards ingested food. This is because T-helper cells develop a memory to recognize the microbes rather than reject them as pathogens (http://search.proquest.com/docview/198955792?accountid=12305). Also the specialized immune system in the stomach differs from the rest of the immune system because it isn't keeping antibodies to destroy threats, rather it has to recognize what is not foreign and not activate reactions (https://www.ncbi.nlm.nih.gov/books/NBK27169/).
Hi Sarah,
DeleteI liked how concise your answer is for question 3. Indeed the specialized immune system in the stomach needs to be different from that of the rest of the body. It needs to be able to distinguish between normal flora and infectious pathogens. I also came across research that talked about T-helper cells that help the body recognize and remember the microbes rather than rejecting them. It is amazing how intricately designed the human body is. Good job!
I agree with Sally that your explanation of the uniqueness of the gut normal flora as compared with the immune system in the rest of the body is quite fascinating. I liked how you pointed out how the immune system in the gut doesn't keep antibodies. It is incredible how even the function of the immune system differs in different parts of the body.
DeleteThis comment has been removed by the author.
ReplyDeleteThe theory mentioned in the article states that antibiotic use could lead to food allergy due to the destruction of normal flora in children’s gut in early life. Their rationale is logical because antibiotic treatment would eradicate both the bad and the good bacteria in the gut, which could lead to sensitization to food allergy because the children who received antibiotics would not have the good flora to digest or support certain food intake. However in my opinion although this theory makes sense, there has not been concrete evidence to support it. The authors of the research “Antibiotic prescription and food allergy in young children” noted that commensal gut flora play an important role in immune system development and immune tolerance. However their research did not explore the mechanisms by which antibiotics cause food allergies. Their conclusion is a mere speculation of weakly supported data.
ReplyDeleteAlthough there has not been strong research and evidence that support the association between antibiotic usage and development of food allergies, we need to look at how exposure to microbes in early life can actually help the immune system. The theory mentioned in the article is related to the hygiene hypothesis, which states that lack of childhood exposure to infectious agents can increase one’s susceptibility to allergic diseases “by suppressing the natural development of the immune system.” By now scientists have not confirmed the mechanism by which bacteria help the immune system. However previous researches showed that mice raised in sterile and germ-free environments have poorly developed immune system. Exposure to commensal bacteria in early life is likened to warming up the engine to start a car instead of leaving the engine cold. Similarly, the immune system can be warmed up and ready to cope with future infections if they were already exposed to bacteria beforehand. Our acquired immunity can better adapt if we are exposed to microbes earlier in life because the cells can recognize the already seen pathogens and fight them off. Specifically neutrophils, an important WBC, are turned on by innate bacterial signals, in turn, initiate the baseline system.
Our digestive tract is laden with cells of the immune system because it is continuously exposed to pathogenic microorganisms. The microfold or M cells in the GI immune system that endocytose a variety of protein and peptide antigens. M cells do not digest these proteins but transporting them into the underlying tissue and present them to T cells in the gut-associated lymphoid tissue. The lymphoid tissue of the GI tract, known as the gut-associated lymphoid tissue, contains several lymphocytes that are indigenous to the digestive system. IgA proteins also dominate the mucosal surface of the GI tract, much more than other immunoglobulin proteins. It has been shown that intestinal IgA is clearly induced by the presence of commensal intestinal microbes, and germ-free animals have greatly reduced mucosal IgA secreting cells. The specialized immune system in our digestive tract suggests that the system was designed to interact with both good and bad bacteria that so often invade our gut. Thus by having cells or proteins such as M cells and IgA that can distinguish between normal flora and harmful pathogens is especially important to not only protect us from infection, but also preserve beneficial microbes in our body.
Love, Bryan. "Antibiotic Prescription and Food Allergy in Young Children." Allergy, Asthma & Clinical Immunology. N.p., n.d. Web. 07 Oct. 2016.
http://www.nature.com/mi/journal/v1/n1/full/mi20076a.html
Your in-depth description of the IgA cells is very interesting Sally! It is very fascinating that the IgA's purpose is two fold in that it protects us from infection, but also allows the normal flora of the GI tract to thrive. It makes sense why antibiotics are not the best idea for a young developing child because it destroys the good flora that the body is designed to protect, that play a part in allergy sensitivity.
DeleteWow, i also agree with Meilia. you do have a very good description on the 3rd question. It was hard for me to find information like that. Its cool how the specialized immune system can distinguis between normal flora and harmful pathogens.
DeleteHey Sally,
DeleteI liked that you pointed out how this idea although it sounds pretty rational is still just speculation with little concrete evidence supporting it. At first I didn't think much of it, but if a child is taking antibiotics they were probably or most likely sick so the allergies could be a result from taking antibiotics, but it could potentially be a result of a certain bacterial infection or some sort of viral infection. The cause isn't entirely clear. They do have some evidence, but how would one prove if there is or isn't any correlation more scientifically? I think this would be a pretty interesting experiment to test the effects of antibiotics on allergies. Way to think outside the box and bring up the uncertainties of theories!
The research presented in the article supports the theory that normal gut flora is essential in building the young child’s tolerance to foreign proteins in food. Because of this, the authors suggest a link between the increase in antibiotic prescriptions, especially broad-spectrum antibiotics, for young children and the rise in food allergy diagnoses. The authors’ conclusion is rational because antibiotics may wipe out not only the infectious bacteria, but also the beneficial gut flora bacteria. This theory is commonly known as the “hygiene hypothesis,” which suggests that a limited exposure to bacteria early in life compromises the immune responses of the normal flora in the gut, resulting in food allergies.
ReplyDeleteAccording to microbiologist David Artis from the University of Pennsylvania, there are more immune cells in the gut than there are in the rest of the body put together. As the normal flora in the gut develops during a child’s early years, beneficial bacteria begin shaping the composition of the normal flora by turning on pathways that allow the immune cells to differentiate between beneficial and harmful bacteria. Most of these pathways involve regulatory T-cells which keep the immune cells in the gut in check. Studies have also found that TLR4 plays a role in developing the composition of the normal flora in the gut. In 2004, immunologist Cathryn Nagler from the University of Illinois discovered that mice with a mutation of TLR4 had an increased susceptibility to food allergies.
Willyard, Cassandra. "Microbiome: gut reaction." Nature 479.7374 (2011): S5-S7.
It's really interesting that you found that TLR4 is involved with the composition of gut flora. Also, that gut flora has an incredible amount of immune cells compared to the rest of the body. And that makes sense, since it is interacting with foreign substances all the time, but has to distinguish between those that are harmful or beneficial.
DeleteAfter reading the article and researching about whether antibiotics is related to allergies, I think antibiotics do play a role in causing allergies. There are a lot of articles that do support this theory as one study from Allergy, Asthma & Clinical Immunology from the University of South Carolina has determined that antibiotic use in the first year of life is associated with an increased risk of developing food allergies. From their data, researchers found that children prescribed antibiotics within the first year of life were 21% more likely to be diagnosed with food allergy than children who did not receive antibiotics. That association increased with the number of prescriptions the child received, to 31% greater with three prescriptions, 43% with four prescriptions, and 64% with five or more prescriptions. (http://snacksafely.com/2016/09/study-exposure-to-antibiotics-early-in-life-associated-with-higher-food-allergy-risk/)
ReplyDeleteExposure to microbes helps the body and immune to be muted towards ingested food. This is done because the memory cells play a major role in this. The exposure to microbes helps the immune system acquire memory from the pathogen so the next time bacteria is introduced, the immune system will be able to recognize them and flush them out. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4056765/
A huge part of the digestive system needs to be protected from foreign cells and viruses. When the immune system is out of balance, food, allergies and inflammations are a sign of that. The gut has millions of bacteria protecting it killing pathogens in it. http://www.inmunologia.org/Upload/Articles/6/2/626.pdf
I never knew how much our body's innate memory ability is how I get to enjoy one of God's Grace and greatest blessings: food.
DeleteThe new research suggests, and has proven, that the cause of the increase of potential food allergies in infants due to early exposure to antibiotics, occurs mainly because the antibiotics alter the composition of “gut flora.” Gut Flora is essential for, and important to the body’s ability to tolerate foreign microbes. The immune system would also work to recognize the microbes and bacteria to late know how to counter them, this fact producing the hygiene theory. Microbes and bacteria that could enter the body through normal activities throughout the day are almost natural vaccines to the infant seeing that the infant would grow an immunity to them. I want to make the argument that building an immunity to everyday microbes and bacteria at a young age could even make the stomach “stronger” in the sense that it could grow to take on either multicultural to even unconventional meals. The main specialized immune system that is associated with the gut is the mucosal immune system. It is the “first line of defense against microbial agents” according to the National Center for Biotechnology Information (https://www.ncbi.nlm.nih.gov/pubmed/11501883). Unique to the immune system, instead of actually creating antibodies and recognizing, it prevents even the contact of the microbe and the antigen proceeding process and prevents invasion. I found it peculiar though gut flora composition is hindered from exposure to antibiotics, it did not result in simple food sensitivity but actual allergic reactions. I assume they are interchangeable.
ReplyDeleteI like how you referred to the flora as essential for toleration of foreign microbes, this in and of itself supports the theory we read in the article. Also, it is interesting to note that exposure to microbes at a young age is like a natural vaccine. Our bodies are intricately designed and God created our GI tract to be a line of defense - this is clearly seen through the success of gut flora against infection/pathogens and the mutualistic relationship between the flora and the mucous membrane surrounding the GI tract.
DeleteThe theory in the article says that the use of antibiotics early in life leads to food allergy later in life because of the effects antibiotics have on gut flora. Gut flora is critical for the body’s tolerance to foreign proteins such as food. Research in this article suggests that antibiotics alter the composition of gut flora, leading to an insufficient GI immune system and higher chances of developing food allergies. I believe researchers are correct or at least on the right tract because of the affect microbes have in building the immune system as a child. In the gestational phase, the fetus has an immune system oriented towards the T_H 2 cell responses which protect the child from attacking material transferred from the mother to the child through the umbilical cord. It is only after birth, when the child is exposed to microbes does he/she shift to a T_H 1 response to ward off allergic reactions. If the child is given too many antibiotics early on in development, microbes aren’t able to enter the GI system and the shift to T_H 1 will not occur. Without T_H 1, the child will be more susceptible to food allergies because their body will recognize food as foreign matter, thus attacking and initiating an allergic response.
ReplyDeleteThe GI system plays a key role in immune system homeostasis because it is the main way the body is exposed to pathogens. The gut is lined by mucosal-associated lymphoid tissue which interacts with the GI tract by increasing intestinal permeability, initiating an immune response, or allowing tolerance. Many types of immune cells are created and released by this tissue.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515351/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337124/
I agree with you that it is essential for babies especially so early on in development, to be exposed to certain microbes in order to build their own immunity. The second a baby is born, they are exposed to hundreds of microbes that they were previously protected from. This leads to the development of their immune systems, but if too many antibiotics are used, the immune development may suffer consequences. They will not be able to acquire the immunity necessary to digest certain foods and their normal gut flora will be lacking essential microbes.
DeleteApproximately 70% of the human body’s immune cells are found in the gut and there are more bacteria in the gut than there are cells in the entire human body. These many bacteria help the body in a multitude of ways, but specifically in reference to the immune system. Normal gut flora is essential in the development of regulatory T-cells and IgA antibody, both of which are important to the development of tolerance to foreign proteins such as food.
ReplyDeleteIn a case study by Love et al., neither postnatal nor prenatal antibiotic exposure was associated with subsequent food allergy diagnosis. However, on average, children between the age of 3 months to 3 years receive 2.2 antimicrobial treatments per year and 10 to 20 courses before the age of 18. Such heavy amounts of antibiotics alter the composition of the gut flora especially if they are broad spectrum treatments which destroy a wide range of microbes along with the desired one.
I think that the dosages and need of antibiotics should be reexamined and that doctors should not be so quick to prescribe antibiotics for illnesses. Not only can antibiotics destroy the essential flora needed for normal digestion and the function of the immune system, but it can also lead to antibacterial resistance and new diseases that are not treatable with antibiotics. Antibiotics are a wonderful blessing and a great discovery for humanity, however, as with all things, we must be good stewards of what God has given us and not abuse them.
Snoek, V. Peters I, Cox E. (2006). “The IgA system: a comparison of structure and function in different species”. Vet. Res. 37(3): 455-67
Love, Bryan L. Mann, Joshua R. Hardin, James W. Lu, Kevin. Cox, Christina. Amroll, David J. Antibiotic prescription and food allergy in young children. Allergy, Asthma & Clinical Immunology. 2016. 12:41
http://www.nutri-health.com/blog/health-topics/digestion-health/your-immune-and-digestive-systems-whats-the-connection/