Probiotic bacteria such as bifidobacteria are now being introduced into many
fermented food products and supplements. The consumption of fermented dairy
products containing probiotics has increased in the past decades. Bifidobacteria
have been a part of human nutrition for centuries, however in recent years they
have been more closely studied for their potential to improve human health and
Anaerobic bacteria (bacteria that can survive without oxygen) belonging to
the Bifidobacterium species are beneficial for the well-being of the host both
in infancy and in later years. It has been shown that bifidobacteria are the
predominant 'friendly' bacteria present in the colon of breast fed infants.
Bifidobacterium longum is one of the major strains of friendly bacteria found
in infants and consumption of fructooligosaccharides (FOS) can help to increase
the population of bifidobacteria in the colon. FOS is found in many foods including
bananas and most vegetables, wheat, onions and garlic and it is recommended
that we consume at least 3 grams per day.
Babies are born axenic (sterile), and the colonisation of the digestive tract
by population of microorganisms specific to each person is done in the first
few days of life. The most significant changes in the intestinal flora take
place from birth until weaning and again in the later stages of life. In between,
the microbial population of the dominant flora remains relatively stable and
prevent potentially pathogenic bacteria from adhering to the intestinal wall.
This has been termed 'the barrier effect'.
However, the balance of bacteria in the digestive tract remains fragile and
susceptible to lifestyle changes. Factors such as stress, change in diet and
drug intake (antibiotics), can disturb this balance. Any imbalance can result
in various disorders including bloating, intestinal pains, nutritional deficiencies
and constipation. Also, a disruption of the barrier effect will lead to a colonisation
of the digestive system by pathogenic bacteria which may result in intestinal
These disorders can be very severe, such as in the case of pseudomembraneous
colitis (a serious type of diarrhoea) induced by the pathogenic bacteria Clostridium
difficile due to the elimination of the barrier effect following a course of
antibiotics. One of the most important characteristics for a probiotic bacterium
is the ability to inhibit the growth of pathogens.
Bifidobacteria have potential probiotic activity that is generally related
to inhibition of pathogens, maintenance and restoration of normal intestinal
flora and an increased immune response.
Research has shown that Bifidobacterium longum adheres to intestinal cells
causing a 'barrier effect'. This prevents pathogenic bacteria from sticking
to the intestine a causing damage. (1) B.Longum has also been shown to increase
the production of a compound released by immune cells called tumour necrosis
factor (TNF). This compound helps immune cells kill off bad bacteria. Probiotic
bacteria such as Bifidobacterium species are effective in preventing and reducing
the severity of acute diarrhoea in children. They are also useful in antibiotic
associated diarrhoea. In inflammatory bowel disease, especially ulcerative colitis
and urogenital infection, probiotics offer a safe alternative to current therapy.
Bifidobacterium longum has been shown to be useful for the treatment of lactose
intolerance. The study discovered that this bacterium could digest lactose that
was present in food. (2) Probiotics, which include bifidobacterium longum, may
be helpful in malnutrition, particularly in lactose intolerance and calcium
absorption, and in constipation. Probiotics have been shown clearly to boost
immunity in the elderly. (5)
Oral supplements increase energy intake and promote weight gain in acutely
ill children receiving antibiotics; synbiotics may confer additional benefits
by increasing bifidobacteria levels. (3) A number of studies have been carried
out on the effect of several probiotic species on treatment and prevention of
intestinal infections. The most commonly used microorganisms are lactic-acid
producing bacteria such as lactobacilli and bifidobacteria belonging to the
human normal microflora. (4)
Irritable Bowel Syndrome
The role of probiotics in IBS has been well researched. Some studies have shown
improvements in pain and flatulence in response to probiotic administration.
It is thought that the most effective way of using probiotics for IBS is as
a preventative measure. (7)
B. longum is of human origin. Bifidobacterium longum belongs to the G.R.A.S.
list (Generally Recognized As Safe), established by the Food and Drug Administration
(FDA) in 1987, for use as fermentation agents in food products. Moreover, B.
longum has been widely consumed in dietary supplements or drugs for more than
50 years, has not been identified in infections, and there are no records of
B. longum related side effects. B. longum produces only L-lactic acid which
is well tolerated even by children.
Contra-Indications and Interactions
Levels of Bifidobacteria decrease during administration of antibiotics. Therefore
supplementation should be considered during antibiotic use, but antibiotics
and probiotics should be taken at least two hours apart.
1. Dr M. Kostrzynska et al, Agriculture and Agri-Food Canada, 2002 2. J Dairy
Sci. 1996 May;79(5):750-7. 3. Clin Pediatr (Phila). 2004 Apr;43(3):239-49. 4.
Int J Antimicrob Agents. 2002 Nov;20(5):313-9. 5. Postgrad Med J. 2004 Aug;80(946):447-51.
6. Curr Opin Infect Dis. 2002 Oct;15(5):501-6. 7. Br J Nutr. 2002 Sep;88 Suppl