What bacteria, viruses, protozoa, fungi.(https://medical-dictionary.thefreedictionary.com/microflora) • Microflora

What is Microflora?

living microorganisms that are
present in less or more numbers in a particular area
e.g. the pharynx  or the rumen, includes bacteria,
viruses, protozoa, fungi.(https://medical-dictionary.thefreedictionary.com/microflora)

Microflora is the diversity of microorganisms
that are regularly found at any anatomical site of any living organism or animal.(https://www.slideshare.net/amanullah9803150/microbial-floraofthehumanbody)

In human microflora present in:

elementary tract, urogenetal tract, ears, mouth (i.e oral cavity), nose (I.e
respiratory tract) and eyes (https://www.slideshare.net/amanullah9803150/microbial-floraofthehumanbody)

The microflora of the digestive canal of human

Acidity of stomach is high so human stomach has small number
of bacteria. Few species of bacteria can survive in acidic environment of
stomach. Like, Helicobacter pylori, this
bacterim was discovered in 1980’s as Microflora of human stomach in acidic
conditions. Recently known that this bacteria is the cause of peptic ulcer and

Human small intestine have small number of bacteria i.e. Streptococci, Lactobacilli and also yeast (Candida
albicans). In the lower part of small intestine, ileum (is a part at the
junction of small intestine and large intestine), Microflora are present in large
number as compared to duodenum.

 Large intestine
contains a great variety of bacteria. Colon in the middle part of large
intestine and bacteria reside in it. The species of bacteria which live there
are Bifidobacterium, Coliforms (E. coli), Bacteroides, Eubacterium, Lactobacillus, Clostridium and Streptococcus. About 20% of fecal
matter consist of bacteria. These bacteria come from colon and not from small
intestine. (https://www.ukessays.com/essays/biology/normal-flora-and-their-benefits.php)


of digestive tract of herbivores

From herbivores, we discuss cow because cow is a ruminant. Cows are not the only ruminant animals. Examples of other
ruminants are gazelles, giraffes, moose, antelope, caribou, sheep, goats, and
deer. Animals which belong to herbivores eat plants like kangaroos, llamas and
camels have modified stomach similar to rumens.

Rumen is a territory for billions of microflora that include
bacteria, protists, fungi and also include some viruses. Microflora which lives
in rumen in different other microbes that are complex organisms and Microflora
also assist one another to help in the digestion of food but microbes not.

Hay is a food that is eaten by ruminants including cow. The
composition of hay is that the cellulose (a complex compound undigested by
herbivores) is present in it and also long chain organic molecules (polymers)
that the animal cannot digest are present. Microbes can help in digestion of
these cellulose and polymer molecules. They break down the cellulose and
polymers into small catabolic bits which the cow can digest and absorb.
Microbes play this activity by special enzymes to convert cellulose into small
digestable particles.



of the respiratory tract:

upper part of respiratory tract is a habitat for a large number of species of
bacteria so upper respiratory tract lacks ciliated epithelium which help in
cleansing action. For instance, nostrils are a colony of enourmous number of
bacteria i.e. Staphylococcus

of the Skin:

Epidermis of the skin of human is not a fertile region for
microorganisms to live because skin surface is dry and acidic upto a little
extinct while microbes require moist region for their proper growth. For
instance,  Propionibacterium acne
and the Staphylococcus epidermidis.

of the Nostrils:

Nostrils are moist due to the presence of mucus inside and it
becomes a habitat for Gram-positive bacteria i.e. Staphylococcus aureus. (https://www.ukessays.com/essays/biology/normal-flora-and-their-benefits.php)

There are many dissimilar types of kinship that the body can induce with the microflora. These are:


It is a “mutual benefit”, as both organisms get benefit from
association from each other. For instance, E. coli synthesize and secrete
vitamin K and B12 which is profitable for host. In return, E. coli gets warm
& nutrient and moist rich environment for its better survival.


In this type of association, one organism gets benefit while
the other is neither benefited nor harmed. Bacteria have no commensalism
relationships with human beings. If bacteria present in our body or on the
body, they play a role which is either beneficial (antagonism of microbes) or

3-Opportunistic (Pathogenic):

E. coli is present in the digestive tract of human and other
organisms where it causes no harm and consequently no disease. But when it
enters into the urogenital tract of organisms, it may be harmful (pathogenic).

aureus is a bacterium of nose microflora found in the upper portion
of respiratory tract. If it gains entry into the cells by any wound or bleeding
or burn it becomes harmful may be pathogenic. (https://www.slideshare.net/amanullah9803150/microbial-floraofthehumanbody)



of Microflora

Major characters of microflora are given below:

Ø Not disease causing:

Microflora are present inside the body and also on the body.
They do not induce diseases in the healthy animals.

Ø Very enourmous in number:

Microflora are very abundant in number. They are present in
living organisms abundantly. For example, a healthy human has about 1013 body
cells but microflora individuals are approximately 1014 in human body. One
fourth of feces contain bacteria.

Ø Found externally to the body:

Mostly, microflora are found on external surface to the body
as on the skin, in the surroundings of eyes, in nose, in throat and also found
on internal surfaces as  lower parts of
urethra and  in large intestine. (https://www.ukessays.com/essays/biology/normal-flora-and-their-benefits.php)

Benefits of microflora:

Preventing colonization by microbial
anatgonism competing with nutrients and space and produce toxic condition or
environmental condition to keep harmful pathogens away (acidity in vagina).

Develop immune system by keeping it
active by providing antigens. (https://quizlet.com/7646560/normal-flora-flash-cards/)

Microflora is essential for us to survive.

They gain their food from the stuff in our pie hole.

If colonies of bacteria are worn out by poisons or
antibiotics, they must be replaced otherwise we would die ultimately. (https://www.quora.com/What-are-the-benefits-of-normal-flora)

They provide a host defence mechanism by taking control on ecological
niches for bacteria, e.g. the intestinal villi.

Bacteria produce and excrete various compounds like vitamin B12 and
vitamin K in the intestine which are important nutrients for host.

The oral microflora assists in immunity through inducing low level of
circulating and secretory antibiotics that kill pathogens. In other words, they
enhance body’s immunity.

The oral bacterial flora kills nonindigenous species by producing
inhibitory fatty acids, peroxides and bacteriocins (it is a protein and bacreria produce it,
it helps in stamping and killing microbes).

Microflora help to digest food as they break down
foodstuffs that are normally indigestible by the host into forms that are
easily digestible by the hosts.

The Microflora protects the host from infection by
harmful pathogenic organisms.

They produce antibacterial substances as by product of
metabolism, so they have a local antibiotic effect which retard the attack of
invaders on host.

They stimulate an immunological response (an
antibody-mediated immune response) as they act as antigens in the human body. (https://www.ukessays.com/essays/biology/normal-flora-and-their-benefits.php)

Disadvantages of microflora:

Microflora is harmful when overgrown (i.e. use of antibiotics) and
misplaced (i.e. urinary tract flora may placed with facel flora). (https://quizlet.com/7646560/normal-flora-flash-cards/)

Microflora may also cause disease in following conditions:

If individual become immunocompromised.

If he change his anatomical location as usual.


There are few limitations of microflora to the human body as
well. For example, most of the microflora are pathogens and may cause
infectious diseases. Similarly, if microflora takes control on certain tissues,
they can cause infection as well as destruction. Likewise, the Microbe may
absorb some of the host nutrients due to competition, leading to the
development of bacterial antibiotic resistance in humans. (https://www.ukessays.com/essays/biology/normal-flora-and-their-benefits.php)