New Research in Babies Microbiomes

New Research in Babies Microbiomes - Babies May

Not Be Born Sterile But With Their Own Bacteria!

Babies Microbiomes

A microbiome is defined as the total amount of microbes and environmental interactions in a

particular environment. Humans have a variety of different internal and external microbes that have

numerous amounts of functions.

Bacterial mutual relationships are crucial for our survival and an imbalanced gut flora may lead to a

number of different disorders.

A pregnant mother is riddled with her own gut flora and numerous amounts of bacteria on her skin

from the external environment. According tomedical science it is thought that the fetus lives in a

sterile environment and that a mothers bacteria does not affect the fetus.

The flora of bacteria in the human body is extremely important as research has showed that early

bacterial flora will shape our immune systems and influence out risks of disease as we get older.

New research into how a microbiome in humans initially develops has put a spin on how medics

think about a fetus’s first microbiome. Evidence is now showing that babies are born with the

bacteria that colonise the mother’s digestive system in the womb. Originally the first bacterial flora to

colonise an infant was thought to be obtained by the mother’s vagina or the environment the infant

was born into.

Information into how bacterial flora affects different systems and diseases in the body can be used to

ensure a baby is given the healthiest start in life.

Esther Jimenez and her colleagues at the Complutense University of Madrid, Spain were the first to

show evidence suggesting mammals may develop a microbiome before birth in the womb; published four years ago.Jimenez conducted a study using mice, in which a genetic marker was added to milk.

The milk containing the labelled bacteria was then fed to eight pregnant mice.

In order to try and control as many external variables that may occur the mice had their offspring

delivered by caesarean section in a sterile environment. This procedure took place one day before

the mice were due to give birth. Each newborn had its first faeces (meconium) collected for

examination; this is normally passed in the first few hours after a baby is born.

The meconium was found to contain the labelled bacteria, suggesting that the bacteria have

transferred from the mother’s digestive system to the fetus during pregnancy. (Jimenez et

al, Research in Microbiology,DOI:10.1016/j.resmic.2007.12.007)

Pilar Francino and her colleagues at the University of Valencia in Spain decided to conduct a study

to see if the same effect occured in humans. The study involved collecting and freezing the

meconium of babies from 20 different women. To eliminate any external factors affecting the study

the outer layer of each sample was removed. Removal of the outer layer would rule out any bacteria

that may be picked after birth. The meconiums were then investigated for any bacterial DNA.

Pilar Francino et al found that the babies’ meconium contained bacteria. The bacteria found in the

meconium is a big discovery but what was more impressive was how developed the bacterial

communities were. The bacterial communities seemed to fall into two different categories.

 Around half of the samples were dominated by bacteria that produced lactic acid such as

lactobacillus.

 The other half of the samples contained enteric bacteria such as Escherichia coli.

Meconium is a tar-like substance, making is extremely hard to extract DNA from although freezing

the meconium makes it easier to extract DNA.

New technology and laboratorial procedures have helped the discovery of the early development of

microbiomes. Previous DNA extraction techniques were not sensitive enough to pick up bacterial

DNA in the meconium.

Research has showed that microboimes can influence our risk of disease therefore Francino’s team

checked on the health of infants at the age’s one and four. The results showed that infants born with

more lactic acid bacteria had a higher risk of developing asthma-like symptoms, those born with

more enteric bacteria were at a greater risk of eczema.

A mother’s lifestyle during pregnancy has been linked to the first bacterial communities that develop

in a fetus. Mothers who consumed organic foods during pregnancy promoted lactic acid bacteria

where mothers who smoked seemed to encourage an enteric microbiome. These findings were

displayed at the international Human Microboime Congress in Paris, France.