Immune System Stimulation
The immune system provides the primary
defense against microbial pathogens that have entered our bodies.
The immune system is extremely complex, involving both cell-based
and antibody-based responses to potentially infectious agents. Immunodeficiency
is primarily caused by diseases such as cancer, AIDS, leukemia or,
to a lesser extent, by more 'normal' or 'common' causes such as
old age, pregnancy or stress. Auto-immune diseases (e.g., allergies,
rheumatoid arthritis and inflammatory bowel diseases) can also occur
due to misdirected immune system activity.
Probiotic cultures have been shown
in a variety of test systems to stimulate certain cellular and antibody
functions of the immune system. Animal studies, as well as isolated
human studies, have revealed the effect of yogurt or lactic acid
bacteria on enhancing levels of certain immuno-reactive cells (e.g.
macrophages and lymphocytes) or agents (like cytokines, immunoglobulins
and interferon). In addition, some studies have shown the improved
survival potential of pathogen-infected laboratory animals that
consume probiotic cultures, as opposed those that follow restricted
diets. Results accumulated so far suggest that probiotics may serve
as an additional tool to help your body protect itself. An exciting
area of research has been documenting the ability of certain probiotic
bacteria to modulate immune dysregulation. Studies have shown that
probiotics are effective in inhibiting the development of allergies
and preventing relapses of inflammatory bowel disease.
Vaginosis
The vagina and its microbiota form
a finely balanced ecosystem. Disruption of this ecosystem can lead
to a microbiological imbalance and the various symptoms associated
with vaginosis. Vaginosis used to be considered a mere annoyance,
but is now being examined for its role in far more serious afflictions
such as pelvic inflammatory disease, pregnancy-related complications
(such as low infant birth weights), and increased susceptibility
to AIDS infection. Vaginosis can be caused by several different
organisms, and in many cases these causative agent may not be accurately
identified. What is known is that lactobacilli predominate in the
healthy vagina, and a lack of lactobacilli (especially those producing
hydrogen peroxide) therefore constitutes a significant risk in terms
of contracting vaginosis. The lactobacilli are thought to maintain
a favorable vaginal pH within an acceptable acidic range and to
inhibit pathogens, possibly through the production of hydrogen peroxide
and other antimicrobial factors. Intravaginal applications of lactobacilli
have been effective in treating bacterial vaginosis to a certain
extent. One study conducted with 13 women showed that consumption
of yoghurt containing L. acidophilus decreased the incidence of
Candida yeast infections. All in all, research so far conducted
would suggest that lactobacilli may be helpful in controlling the
incidence, severity and duration of vaginal infections, but larger,
more controlled studies are needed in order to verify this.
Allergies
Rates of allergies are on the rise
in industrialized nations. It is estimated that the incidence of
asthma in the United States actually doubled between 1980 and 2000.
Scientists have proposed a hypothesis known as the 'hygiene hypothesis'
to explain the rise in allergic conditions such as asthma and eczema.
This hypothesis is based on observations that lower allergy incidence
is associated with environments that have greater numbers of microbes,
such as day care centers, farms, or in homes with siblings or pets.
Sanitary living environments and the consumption of processed foods
have limited the number of microbes in the diet. The hypothesis
suggests that the exposure of infants to microbes before the age
of six months helps the immune system to mature and renders it far
more tolerant when exposed to allergens later in life ("Day
Care May Boost Immunity To Asthma," August 2000, Washington
Post.)
Of course, increasing our exposure
to microbes is a preventative process that should be carried out
very carefully. The above-mentioned hypothesis led researchers in
Finland to conduct a study evaluating the effects of a Lactobacillus
strain on the incidence of atopic eczema in 132 infants at high
risk of developing eczema. The study was double-blinded and placebo-controlled.
Heavily pregnant mothers, merely two to four weeks short of delivery,
as well as newborn babies through six months of age, were given
Lactobacillus rhamnosus GG. Infants were followed through two years
of age and the incidence of recurring atopic eczema was recorded.
The study reported a 50% drop in this incidence of recurring atopic
eczema in the group receiving the probiotic supplement. A follow-up
study of the same children indicated that the same trends were still
present at 4 years of age. These results suggest that exposure to
the right types of microbes early in life may significantly decrease
the risk of allergies developing.
