: spores of various species are used as probiotics, although they are generally
absent from the normal microflora of man. Spores of all strains are immunogenic
when they were given orally to mice
cereus persist in the mouse gastrointestinal tract for up to 18
days postadministration, demonstrating that these organisms have some ability
to colonize. Spores of one B. cereus strain were extremely sensitive
to simulated gastric conditions and simulated intestinal fluids.
clausii polyantibiotic-resistant (penicillin, cephalosporin, tetracyclins,
macrolides, aminoglycosides, novobiocin, cloramphenicol, thiamphenicol,
lincomycin, isoniazid, cycloserine, rifampicin, nalidixic acid, pipemidic
acid) (oral suspension 2 billion spores per 5 ml vial) (Enterogermina®).
B. clausii strains release antimicrobial substances in the medium.
Moreover, the release of these antimicrobial substances was observed during
stationary growth phase and coincided with sporulation. These substances
were active against Gram-positive bacteria, in particular against Staphylococcus
aureus, Enterococcus faecium, and Clostridium difficile.
The antimicrobial activity was resistant to subtilisin, proteinase K, and
chymotrypsin treatment, whereas it was sensitive to pronase treatment.
The evaluation of the immunomodulatory properties of probiotic B. clausii
strains was performed in vitro on Swiss and C57 Bl/6j murine cells.
These strains, in their vegetative forms, are able to induce NOS2 activity,
IFN-g production, and CD4+ T-cell
When B. subtilis and B. clausii spores are inoculated intragastrically
in mice, no detectable amounts of vegetative cells are found in intestinal
samples, probably because of high toxicity of the conjugated bile salt
taurodeoxycholic acid against Bacillus species. Both spores and cells were
detected in the lymph nodes and spleen of one mouse. Bacillus is present
in the intestinal tract solely as spores and that nonpathogenic Bacillus
spores may germinate in lymphoid organs, a finding reminiscent of B.
anthracis germination in macrophages. These results indicate that any
claimed probiotic effect of B. subtilis should be due to spores or, alternatively,
to vegetative growth outside the intestineref.
pumilus strain generates particularly high anti-spore IgG titers.
Spores of B. pumilus and of a laboratory strain of B. subtilis
were found to induce the proinflammatory cytokine IL-6 in a cultured macrophage
cell line, and in vivo, spores of B. pumilus and B. subtilis
induced the proinflammatory cytokine TNF-a and
the Th1 cytokine IFN-g. The B.
pumilus strain and one B. cereus strain (B. cereus var.
vietnami) were found to produce a bacteriocin-like activity against
other Bacillus species.
Lactobacillus-exposed human myeloid DCs (MDCs) up-regulate HLA-DR,
CD83, CD40, CD80, and CD86 and secreted high levels of IL-12 and IL-18,
but not IL-10. IL-12 was sustained in MDCs exposed to all 3 Lactobacillus
species in the presence of LPS from Escherichia coli, whereas LPS-induced
IL-10 was greatly inhibited. MDCs activated with lactobacilli clearly skewed
CD4+ and CD8+ T cells to Th1 and Tc1
polarization, as evidenced by secretion of IFN-, but not IL-4 or IL-13.
These results emphasize a potentially important role for lactobacilli in
modulating immunological functions of DCs and suggest that certain strains
could be particularly advantageous as vaccine adjuvants, by promoting DCs
to regulate T cell responses toward Th1 and Tc1 pathwaysref.
The average human gut contains about 100 different species of bacteria,
including 'good' bacteria, such as Lactobacillus and Bifidobacterium,
which aid digestion, bolster the immune system and battle for space with
'bad' bacteria, such as those that cause food poisoning. Some of these
beneficial bacteria are added to products such as live-culture yoghurt.
Probiotic foods and supplements are big business — the worldwide market
is worth around US$6 billion a year.
pasteurii (a.k.a. Bacillus pasteurii) to the test in a human
gut simulator that mimics the flora and acid environment of the digestive
system, from stomach to descending colon. In less than 24 hours, B.
pasteurii broke down around 60% of the urea in the system, without
harming the natural bacterial mix. The bacteria must remain in the human
gut long enough to do their work, and their by-products must be harmless.
lactis in which the thymidylate synthase gene thyA has been
replaced with an expression cassette for the IL-10
gene, simultaneously enabling the microorganism to produce the cytokine
and to render it dependent on thymidine or thymine for survival, is used
to treat inflammatory
bowel diseases (IBDs).
A recombination event to restore the thyA gene (from a donor such as Lactobacilluslactis
subsp. cremoris), if it should occur at all, would simply replace
the expression cassette and return the bacterial genome to its premodification
state. When a commercially available probiotic preparation is irradiated,
halting bacterial proliferation but preserving its DNA, and is given to
mice, the irradiated probiotics perform as well as live bacteria in reducing
inflammation. The purified probiotic bacterial DNA alone similarly reduces
inflammation in mice with experimentally induced colitis. The probiotic
DNA acts through TLR9
: mice without the gene for TLR9 protein cannot benefit from probiotics,
either living or irradiated, or from probiotic DNAref.
Taken together, insights into mechanisms of probiotic activity open new
possibilities for probiotic therapies. For example, purified probiotic
DNA or irradiated probiotics may be safer than viable preparations, and
could be used by people with compromised immune systems. Live probiotics
are not the best way to deliver the DNA : the food starts to ferment. If
you add live bacteria to orange juice, you get a different taste every
hour. DNA that boosts the immune system could even be given by pill or
injection. But probiotic foods have a raft of other benefits that rely
on using live bacteria : they need to reproduce if they are to crowd out
harmful strains and combat food poisoning, for example. Probiotics manufacturers
would be delighted if they thought they could put it all in a pill (it
would be cheaper and the shelf-life would be a lot longer), but they usually
need to be alive — immune stimulation is the exception.
bowel disease (IBD),
especially Crohn's disease (CD), probably results from failure to downregulate
a chronic Th1
intestinal inflammatory process. Induction of a Th2
immune response by intestinal helminths diminishes Th1 responsiveness.
In an initial treatment and observation period, a single dose of 2500 live
suis eggs was given orally, and patients were followed every 2
wk for 12 wk. Baseline medications were continued at the same dose throughout
the study. To assess safety and efficacy with repetitive doses, two patients
with CD and two with UC were given 2500 ova at 3-wk intervals as maintenance
treatment using the same evaluation parameters. RESULTS: During the treatment
and observation period, all patients improved clinically without any adverse
clinical events or laboratory abnormalities. 3 of 4 patients with CD entered
remission according to the Crohn's Disease Activity Index; the fourth patient
experienced a clinical response (reduction of 151) but did not achieve
remission. Patients with UC experienced a reduction of the Clinical Colitis
Activity Index to 57% of baseline. According to the IBD Quality of Life
Index, 6 of 7 patients (86%) achieved remission. The benefit derived from
the initial dose was temporary. In the maintenance period, multiple
doses again caused no adverse effects and sustained clinical improvement
in all patients treated every 3 wk for >28 wkref.
A drinkable concoction containing thousands of pig whipworm eggs could
soon be launched in Europe. At the moment the concoction cannot be stored
for long, so doctors or hospitals would have to prepare fresh batches of
the eggs for their patients. But a new German company called BioCure,
whose sister company BioMonde sells
leeches and maggots for treating wounds, hopes it will soon solve the storage
problem. It plans to launch a product called Trichuris suis ova
(TSO). The pig whipworm was chosen as it does not survive very long
in people. Patients would have to take TSO around twice a month. The human
whipworm, which infects half a billion people, can occasionally cause problems
such as anaemia
children with autism
are known to have higher levels of Clostridium
in their guts : many autistics also suffer from bloating, belly-ache and
diarrhoea and toxic by-products of the bacteria may be absorbed into the
blood and travel to the brain, where they may play a role in ill health.
Probiotic food supplements that lower levels of Clostridia will
allay some symptoms of autism : Lactobacillus
plantarum 299v, looks especially promising. The bacterium binds
to the gut lining and stimulates its growth : as well as out-competing
other bacteria, it also lowers gut pH, which helps the digestive tract
to fight infection. It stays in the gut for days and has never been associated
with any health problems.
acidophilusmay protect against infections in the genital and urinary
tracts. Lactobacilli have the potential to help protect women from
UTIs in a number of ways:
maintain a low pH environment
hinder Escherichia coli growth
produce H2O2, which produces an environment hostile
in one 2001 study, a drink containing Lactobacillus GG did not appear
to protect against UTI recurrences, possibly because the dose was too low
for the healthy bacteria to flourish
coli 83972 is being investigated because it can grow in the urinary
tract without causing infection, crowding out other potentially harmful
bacteria. Some research suggests that it may be protective in certain individuals,
including those with spinal cord injuries or urinary catheters.
jenseniiengineered to secrete functional 2-domain CD4
(2D CD4) can inhibit HIV-1
infectivity in vitro and may enhance vaginal protection
in Sweden probiotics are routinely prescribed after surgery
to help boost patients' immune systems and counter any stomach upsets that
are triggered by antibiotics
the friendly bugs may also prove useful against diarrhoea, colitis and
Probiotic bacteria incorporated into food can confeer a range of