Bet You Didn’t Know this about the Gut Microbiome!

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When the word “symbiosis” comes up, people typically think of lichens – composite organisms established from fungi and algae. Or they think about clownfish and sea anemones – a relationship seared in our memories thanks to Finding Nemo. Humans, however, don’t come to mind. It turns out, however, that we are helped by millions of bacteria that live inside us. These bacteria are not only more numerous than we might guess, but also play roles extending beyond digestion. Here are some interesting facts about the gut microbiome:

  1. The gut microbiome is enormous – there are upwards of 30 trillion bacterial and fungal cells in the gastrointestinal tract, most of which reside in the colon. This makes the number of microorganisms housed in the gastrointestinal tract equal to, if not slightly higher than, the number of cells that compose the human body itself!
  2. While the number of human cells might just equal the number of cells constituting the gut microbiome, the number of genes encoded by the human genome is no match for the number of genes encoded by the gut microbiome. The gut microbiome encodes approximately 150 times the number of genes encoded by the human genome.
  3. These extra genes come in handy to humans. These genes allow the bacteria to produce an array of enzymes that help humans digest complex carbohydrates in the large intestine and extract nutrients from them. In the absence of these enzymes, the human body would not have been able to get nutrients from a lot of the food we consume.
  4. The gut microbiome also helps synthesize vitamins B and K in the body. Vitamin B plays an important role in metabolism, while vitamin K is required for blood clotting. The gut microbiome also helps the body absorb chemicals such as phytochemicals and polyphenols that function as antioxidants.
  5. Our diet influences the composition of our microbiome. Those who consume a plant-based diet and those who consume a diet rich in animal-based-products have gut microbiomes that are enriched in different bacterial species. Consumption of foods rich in probiotics can also help alter the composition of the gut microbiome.
  6. The gut microbiome plays an important role in modulating inflammation. Inflammation is a process by which the body stimulates the immune system by secreting chemical signals called cytokines. While this system is beneficial If the body is being invaded by pathogens, continuous inflammation leads to tissue damage. While some bacteria can protect against chronic inflammation by producing anti-inflammatory cytokines, some species can cause inflammation as well.
  7. A disrupted microbiome – particularly a disruption in which there is an over-enrichment of microbes that cause inflammation – has been associated with numerous diseases including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), colorectal cancer, and type II diabetes. While it may seem difficult to believe that the microbes in the gut can play a role in notoriously complicated diseases like IBD, fecal transplants from healthy individuals that aim to rebalance the microbiome of a patient suffering from IBS or IBD have led to an alleviation of symptoms.
  8. The gut microbiome can even regulate mood and memory – aspects of the functioning of the human body that don’t seem connected with the gut and digestion at all. In fact, the gut microbiome produces numerous neurotransmitters that regulate mood, including serotonin, the hormone that causes the feeling of well-being and happiness.

New research has only begun to elucidate the complex connection between the food we consume, the bacteria in the gut that help digest it, and the resultant effect on our long-term health. The interconnectedness between the bacteria in the gut and the chemical responses they stimulate in the body is evidence of the complex ways in which organisms depend on one another, and how the tiniest of organisms can have massive impacts on our health.

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https://link.springer.com/article/10.1007/s12328-017-0813-5

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