Bacteria Genomes - BIFIDOBACTERIUM LONGUM
Bifidobacterium longum keeps the human digestive system running
smoothly
One of the
most important residents in the human gastrointestinal tract, B.
longum keeps the digestive system running smoothly, blocks
the growth of harmful bacteria, and boosts the immune system. The
organism ferments sugars into lactic acid and has many health benefits
for humans and is often the dominant bacterium found in humans.
It is a Gram-positive, anaerobic, branched rod-shaped bacterium.
Researchers
have identified a number of proteins that are specialised to help B. longum interact with the human host and persist against
harmful bacteria and future reseach will now closely look at which
genes allow B. longum to live in different environments
such as dairy products, vegetables and the human gastrointestinal
tract.
Bifidobacterium
longum is among the first to colonise the sterile digestive
tract of newborns and predominates in breast-fed infants. Formula-fed
infants have a different microflora, and this may be related to
the higher risk of diarrhea and allergies in these babies.
Recognising
the many benefits to good health, lactic acid bacteria are included
in dairy foods and taken as supplements in powder, liquid extracts,
or tablets and this has also resulted in people supplementing their
diets with these microbes, which are also called probiotics (meaning
'in favour of life'). Live cultures in yogurt have been used as
a remedy for hundreds of years to support immune function and doctors
recommend bacterial supplements to patients who take antibiotics,
suffer from bacterial, viral or fungal infections or have various
digestive problems.
Other potential
uses of B. longum are being investigated in separate studies.
Japanese researchers showed that the microbe might be useful as
a gene delivery vector for cancer therapy. They injected the bacterium
into the tail veins of rats and demonstrated that B. longum is accumulated in the tumor.
Comparative studies
of lactic acid bacteria may lead to better understanding the microbes'
roles in food fermentation and human health.
References:
http://gnn.tigr.org/articles/10_02/bifido.shtml
Proc Natl Acad Sci U S A 99(22):14422-7 (2002)
http://ift.confex.com/ift/2001/techprogram/paper_6788.htm
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