Introduction
Immunity and our gut have a very important relationship. Our body is protected from potential pathogens by a layer of cells lining the gut (epithelial cells) and by chemical barriers. Gut flora triggers immune functions in the epithelial cells. If these cells are not able to communicate with the flora, there would be no physical barriers to various infections. They compete with possible pathogens for space, and if a person is healthy, the bacteria are already in work, and there is no space for pathogens. One type of species produces an antibacterial substance that counters Gram-negative bacteria ( E. coli, Salmonella, and several different types of bacteria that cause respiratory infections).
Maintaining a balance in the immune system by getting rid of invading pathogens, while keeping self tolerance to avoid autoimmunity, is very important for the body’s health. The gut bacteria present in the gastrointestinal tract allows for the regulation of immune homeostasis , which is just one of the benefit it provides. It has recently become more known that changes of gut microbial communities have the ability to cause immune dysregulation, which leads to autoimmune disorders
The mammalian gastrointestinal (GI) tract is a place for the huge and intricate community of commensal bacteria. The gut microbial community(microbiota) has co-evolved with its host over millenia and provides advantages in various ways such as digestion, nutrient production, immune system regulation, pathogen protection, and detoxification. The immune system plays a critical role in keeping the body healthy by providing an equilibrium between the eradication of invading pathogens and maintenance of tolerance to healthy safe-tissue. In the case of patients having autoimmune disease disorders, the mechanism to keep up self tolerance is a failure. The result is that the immune system accidentally attacks and destroys healthy self-tissue. Due to many technological advancements such as “next generation sequencing”, the field of gut microbiota and autoimmunity became a more transparent field. The technology has provided culture independent microbial analysis that makes the characterization of these complex comensal communities possible. More progress has been made since researchers begun to unveil the cellular and molecular interactions between commensals and the mucosal immune system, specifically with the help of animal immune models.
We make multiple decisions everyday about what we put into our body, and these decisions affect the immune system. As I have learned more and more about gut bacteria and its benefits, I want to learn its effects on our body when we consciously put into our systems or the systems of other organisms. Different foods have different bacteria, and eating food like homemade yogurt, and kombucha has the type of flora that increase the PH of our immune system which kills the bad bacteria off.
Having a unhealthy gut is damaging for one's health and there many reasons why. Gut is influenced by a junk diet, and the effects will be discussed in this grant by experiments. Medication like antibiotics, and acid blocking gut inhibit gut functions and block the digestive system. Infections such as small intestinal bacteria growth damages the gut and effects the microbiomes. Mold and mercury toxins kill the gut flora, which damages intestinal functions. Chronic stress changes ones gut nervous system, creating a drippy gut and altering the normal bacteria in the gut.
Many diseases are caused by harmful bacteria, but research also shows that gut flora can also be used to prevent diseases, and build the immune system. My question is what’s the relationship between gut flora and the immune system in different organisms, and is the relationship beneficial to the organism or does it affect it negatively.
Experimentation(step 2)
Scientists are discovering new things about gut bacteria everyday, but to answer my question and find any hard evidence, experiments will have to be performed. I will employ two experiments: both with mice as they are best way for researchers to figure out the immune system and gut flora of the humans.
For this experiment, gut bacteria was transplanted from wild mice to clean lab mice. The goal of this experiment was to transplant gut bacteria wild mice to clean lab mice and see the effects by testing it with a virus. To start this experiment,scientists had to figure out how to select the mice with the strongest immune systems. Using clean lab mice would not be logical as it would not relate to humans as humans are not constantly sterilized and raised in such clean conditions. The solution was to put the lab mice with mice from pet stores. I allowed for the principles of survival of the fittest to see which mice would survive. The surviving mice had a immune system that was stronger.
After testing this on many mice in the D.M.V area, I collected about 400 mice and compared their DNA, genetic history, and DNA with a strain of lab mouse, as well as wild mice from different regions of the world. Their gut bacteria was similar in some ways, but the microbiomes within it varied vastly. The researchers then transplanted the gut bacteria from wild mice into the lab mice. The only mice donors that were used were those that didn’t have any infection. This was so researchers could notice the effect of the gut microbiome in its natural way. The next part of the experiment was to put their immune system to the test. They exposed the mice with the transplant to a flu virus and to conditions that would eventually lead to gastrointestinal disease or colon cancer. The offsprings of these mice were also exposed for four generations, and all of them still had the wild microbiome.
I expect this experiment to able to answer the importance of healthy gut microbiomes and bacteria. This experiment should explain how living conditions are very important for the development of a strong immune system. The mice living in different parts of the world, as well as pet stores had a different microbiota then the lab mice because of the conditions they were exposed too. They have taken in different types of bacteria, and slowly built their immune system up. This experiment should be proof that gut flora is beneficial for the immune system.
Research has shown that diet has the ability to affect some autoimmune diseases. For this experiment, four sets of human twins in which two were obese and the others were lean. The microbes of these twins were introduced into two different groups of mice by the process of transplantation. These mice were raised like the lab mice in the previous experiment: germ free. When mice stayed in the same cage, microbiota transfer is common between cage mates. The researchers wanted to know about the impact on a continental diet. These diets are high in saturated fats and low in fiber and were used to determine their effect on obesity fighting microbes. The mice had initially been given food that was low in saturated fat and high in fruits and vegetables. The scientists repeated the experiment, but this time fed the mice a diet high in saturated fats and low in fruits and vegetables.
This answers many parts to the question. The relationship between the immune system and gut flora depends on many factors. It explains how consuming a diet rich in protein, calcium, and healthy bacteria is beneficial to the body, and strengthens the immune system.
Procedures and Expected Results
I would need lab mice with strong immune systems.
I would put them in different habitats such as the pet store for a month and a half and see who would survive.
I would then test for common mouse pathogens, and the lab mice would show the same immune responses as the pet store mice as they would be exposed to viruses, parasites, and bacteria.
I would collect 400 wild mild mice for different comparisons.
Through DNA analysis, and fecal samples, these mouse would be compared to a lab mouse strain, as well as strains of mice from all over the world. New biotech would be used to analyze these samples.
The gut bacteria would then be transplanted from the collected mice into the lab mice that survived in the pet store.
The mice receiving transplant were exposed to flu virus, as well as with intestinal worms in order to see how they would be impacted by yellow fever.
Offsprings for up to to four generations were tested.
Expected Results:
After these trials, and months of exposure, mice would start to show results. The immune responses shown by infected and transplanted group would show that they had developed a stronger immune system. My hypothesis is that there would be a high rate of survival of mice with transplanted gut bacteria and a low survival rate for lab mice. These results will show how the exposure to different conditions builds the immune system. They carry microbiomes that have evolved to help their hosts cope with these problems, making the immune system less reactive to harmless microbes and other dangers, but more reactive to other, dangerous ones.
Alternate: The lab mice would not react well with the transplantation and react worse to the virus. The offsprings would be more affected every generation.
Experiment two
I had to find two sets of twins, in which one pair was obese and the other was lean.
I would collected fecal samples from the twins.
I would introduce these samples to different groups of mice.
Then the weight and change in their metabolic make up in mouse groups, when the same diet was fed.
These results would then be collected and analyzed.
They would then be tested on a continental diet, which has fats and low fiber.
I would put mice carrying microbes from both twins in same cage and analyze these results.
Expected Results:
Mice with microbes from the lean twins would be lean, and the mice populated with microbes from the obese twins would gain weight. The cage part of the experiment would end up being in favor of lean mice. Their bacteria would not affect the mice(lean) as they would have a strong immune system, and the other mice(obese) would have a weaker immune system, thus it would be influenced easily. Based on trends, the diet would overtake the lean mice’s influence. Obesity would be developed.
Alternate: The mice with the lean and obese microbes would have opposite effects. The mice would react badly because of their gut bacteria make up and get fat with the lean microbe and lean with the obese. microbe.
Summary:
The relationship between the immune system and gut flora is very beneficial. Maintaining a balance in the immune system by getting rid of invading pathogens, while keeping self tolerance to avoid autoimmunity, is very important for the body’s health. The gut bacteria present in the gastrointestinal tract allows for the regulation of immune homeostasis.
The experiments done show that these results in mice can slowly be applied to humans with the help of more technological advancements and further research, as well more validated results.
Citations
Wu, H., & Wu, E. (2012, January 01). The role of gut microbiota in immune homeostasis and autoimmunity. Retrieved April 13, 2018, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3337124/
2. Gut Microbes and Diet Interact to Affect Obesity. (2016, April 04). Retrieved April 13, 2018, from https://www.nih.gov/news-events/nih-research-matters/gut-microbes-diet-interact-affect-obesity
3. PennisiOct, E., PriceApr, M., KaiserApr, J., Gilbert, N., PainApr, E., & WadmanApr, M. (2017, December 08). How gut bacteria saved 'dirty mice' from death. Retrieved April 13, 2018, from http://www.sciencemag.org/news/2017/10/how-gut-bacteria-saved-dirty-mice-death
4. How Good Gut Health Can Boost Your Immune System. (2016, June 27). Retrieved April 13, 2018, from https://www.ecowatch.com/how-good-gut-health-can-boost-your-immune-system-1882013643.html