Population of microbes inhabit the skin and
mucosal surfaces in various parts of the body. What are the optimum conditions
for bacterial growth that leads disparate bacteria to inhabit human body? First
and foremost, warm temperature (37°C) plays a crucial role in the growth of
bacteria, so mesophiles, which are warm-blooded animals, provide an ideal
environment for bacterial growth. Second, moisture is important as it is the water
source for bacteria to grow. Consequently, moist tissues in the body like the
mouth and nose are prone to bacterial growth. Third, majority of the bacteria
require oxygen to grow. Fourth, the pH of an environment is a prominent factor for
bacterial growth. Most types of bacteria prefer pH level of the human body. Furthermore,
bacteria cannot survive at extreme pH levels.
Although negative perception on bacteria is
deeply entrenched in people’s mind, most of the bacteria associated with humans
are reported not be harmful at all but are necessary for maintaining healthy
body.
In this post, I will be discussing about bacteria
in the gut flora; gut flora is the human flora of microorganisms that normally
live in the digestive tract that have necessary functions for their hosts.
Overall, bacteria in digestive tract help digestion, synthesize vitamins, and
create enzymes that the human body cannot synthesize. The average human body consists
of about ten trillion microorganisms in the gut.
In the stomach, the high acidic condition
impedes the bacterial growth. However, Streptococcus, Staphylococcus,
Lactobacillus, and Peptostreptococcus inhabit the stomach. Patients suffering
from chronic gastritis and peptic ulcer disease may have Helicobacter pylori
that is classified as a carcinogen for gastric cancer.
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| Enterobacteriaceae Copyright Centre for Disease Control |
In the small intestine does not have a great
amount of bacteria due to the influence of the stomach. The alkaline condition
of the small intestine facilitates the growth of Enterobacteriaceae. The
bacterial flora of the small intestine provide regulatory signals promote the
function and the utility of the gut.
The large intestine contains the most number of
bacteria in the human body. Faecalibacterium prausntitzii is the most common species
in healthy adults. Escherichia coli lives in the colon. I wanted to mention the
strains of E.coli in virtue of extensive studies on it. They have many
favourable functions such as the production of vitamin K2 and prevention of
pathogenic bacteria from establishing in the intestine. However, serotype O157:H7,
one of the strains of E.coli, poses harm to human health as it causes food
poisoning.
In conclusion, according to various credible
research results, the gut flora and humans have symbiotic and mutualistic
relationship. The microorganisms ferment energy substrates in excess, train the
immune system, hinder growth of detrimental species, regulate the development
of the gut, synthesize vitamins like vitamin K and biotin, and produce hormones
that signals to store fats.
*
In this post, I used bacteria as the alternative term of microorganism owing to
the fact that bacteria are categorized under microorganism.
[Reference]
https://en.wikipedia.org/wiki/Human_microbiotahttp://www.livestrong.com/article/126073-four-conditions-bacterial-growth/
http://textbookofbacteriology.net/nutgro_5.html
https://www.quora.com/What-is-the-difference-between-a-microorganism-and-a-microbe
http://www.medicalnewstoday.com/articles/68511.php
KSJ
Nice post. Well what can I say is that these is an interesting and very informative topic on bacteria in human stomach
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