The Gut Microbiome - Simone Khandpekar
Abstract
The gut microbiome consists of many microbes and bacteria, almost up to 100 times the host. (Kho and Lal). These help to digest the food consumed, and also play a major role in both mental and physical health. The gut microbiome has been shown to be linked to inflammation, diabetes, and more (Fu et. al). The gut microbiome may also influence weight and metabolism. There has been research showing connections between an imbalanced gut microbiome and mental and neurological disorders, like depression and Autism Spectrum Disorder (Kho and Lal). There is a growing importance on the gut microbiome and its ever-changing effects on the human body.
Typical Gut Microbiome
Healthy individuals may have more than 1000 species of bacteria (Bull and Plummer). There are trillions of microorganisms, and about two thirds of the gut is unique for each individual (Bull and Plummer). The gut microbiome is considered to be very diverse, when compared to other body sites. The body has many cavities and areas of bacterial colonization, including the nasal cavity, throat, genital organs, and mouth cavity. (Kho and Lal). Each individual microbiome can vary from one person to the next. It is composed of mainly anaerobic bacteria (do not require oxygen to grow), facultative anaerobes (may or may not have oxygen to grow), and aerobes (require oxygen to grow) (Bull and Plummer). Bacteroidetes and Firmicutes are some of the most dominant phyla in the gut microbiome (Bull and Plummer). The widely complex microbiome consists of up to 100-fold more genes than the host. These genes all encode multiple different enzymes, contributing to the host’s metabolism and physiology (Kho and Lal).
Importance of the Gut Microbiome
The gut microbiome may affect the host’s body. Gut bacteria are commonly thought to digest food and create nutrients from food consumed. For example, a rare species called Bacteroides are able to digest xyloglucans, nutrients found in vegetables like onions and lettuce (Shreiner et. al). Studies have shown that it is related to obesity: many have conclusions which correlate lower diversity of the gut microbiome with obesity. In addition, the same lower bacterial diversity has been seen in those with Inflammatory Bowel Disease, Type 1 diabetes, psoriatic arthritis, and eczema (Wu and Lewis). These reproducible studies point towards the conclusion that it is important to have species-rich gut microbiota. This helps to protect against influences of the environment. Scientists can characterize and monitor for changes in the gut microbiome (Wu and Lewis). They have been able to point out direct associations with various diseases, and this imbalance is called dysbiosis (Wu and Lewis). The value of dysbiosis in the future is promising, as professionals can use it as a tool to recognize biomarkers of diseases like atherosclerosis (Fu et. al). Dysbiosis is linked to increased intestinal permeability, which can cause an increase of bacterial secretions (Fu et. al). These products cause low-grade chronic inflammation (Fu et. al).
Development of the Microbiome.
The microbiome is developed as early as being a fetus. This is through transmission between the fetus and mother in the amniotic fluid, placenta, and meconium. In addition, method of delivery can affect the gut microbiome. Studies have determined that infants delivered through the birth canal resulted in higher bacteria count than those delivered by Cesarean section (Bull and Plummer, Clapp et. al). These differences are not detectable at six months (Bull and Plummer). As the infants grow, their diet makes up their microbiome too, with a diet of breastmilk having a connection to increased amounts of IgA and Bifidobacterium; this leads to decrease of IL-6, and thus a decrease of inflammation, corresponding to a lower risk of age-related gastroenteritis (Clapp et. al). Breast milk’s non-digestible sugars have been shown to create an environment suitable for some specific species of bacteria (Clapp et. al).
Gut Microbiome and Mental Health and Disorders
Animal studies have shown that the composition of the gut microbiome has an important role in the functions of the central nervous system. These functions include inflammation,
neurotransmissions, and the hypothalamic-pituitary adrenal axis (Jiang et. al). Translocation of bacteria, where chromosomes of the bacteria change location, can have an amplifying effect on depression, causing it (Jiang et. al). There is also a possible link between the gut microbiome and neurological disorders. This includes Autism Spectrum Disorder. Studies have seen a significant association with Autism Spectrum Disorder, dysbiosis, and gastrointestinal problems (Kho and Lal). They point towards mediating gastrointestinal dysfunction to help with triggers and Autism Spectrum Disorder-associated symptoms (Kho and Lal).
A Healthy Gut Microbiome
It’s important to have a healthy and balanced diet always. Fiber intake is crucial, as is eating
fruits and vegetables (Spector). Consuming a variety will lead to a variety of different chemicals and fibers, helping support different bacteria in the gut microbiome (Spector). Polyphenols are antioxidants which can be found in green tea, berries, and nuts (Spector). When taking antibiotics, it is important to finish off a course; not finishing it can lead to resistant microbes and overtaking of the natural state of the gut microbiome.
Conclusion
It is important to be aware of the importance of the gut microbiome. It has influence over many aspects of life, including both physical and mental health. The gut microbiome can cause illness, but there are techniques and ideas by scientists and professionals to utilize it. It is urged to be conscious of the gut microbiome, and to have a healthy diet and lifestyle.
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