Friedrich-Breuer-Str. 86 - D-53225 Bonn
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GASTROSAN
Soy Milk Protein fermented with Lactobacillus
bulgaricus LB 51
Yoghurt is produced
by fermentation of milk usually by the two microorganisms Streptococcus
thermophilus and Lactobacillus bulgaricus. Both use lactose as
energy and carbon providing substrate which they convert to lactic acid. Nitrogen
is derived from the protein components of milk. L. bulgaricus
excretes proteolytic enzymes at a fairly high rate which hydrolyse the milk proteins
(casein) to peptides and also single amino acids. The amino acids
are used as building blocks for the synthesis of bacterial proteins. (S. thermophilus
has only a minor proteolytic activity, but it profits from the
proteolysis of the simultaneously present L. bulgaricus). Microorganisms have the
desire to maintain their biotop in a suitable state for their own
survival. They do this among others by the excretion of certain substances, suitable
for themselves but also of substances detrimental to competing
microorganisms. A simple method to preserve moisture necessary for bacterial growth
is the excretion of polysaccharides which absorb and retain water. The
gelification of yoghurt is partly caused by such excreted polysaccharides (in particular
by Streptococcus thermophilus).
Of much higher
interest than the polysaccharides are, however antibiotic proteins excreted by
bacteria, the so-called bacteriocins, which impede or
destroy competing microorganisms. The structural information of the bacteriocins
or rather "prebacteriocins" is preserved on the bacterial
chromosomes or on plasmides. Prebacteriocins are like any protein synthesized by
ribosomes; subsequently they are modified into the actual bacteriocins, by
chain cleavage and by enzymatic transformation of common amino acids to uncommon
ones, which are not found in the genetic code and which are
otherwise very rare in proteins (MONTVILLE, 1993).
While excretions
are responsible for the pathogenic effect of certain bacteria, the proteins
excreted by lactic bacteria are of a for humans
"friendly" nature, they act antimicrobially against other, possibly pathogenic
organisms, but do not do damage to humans and are thus beneficial
by this antimicrobial effect. SILVA (1987) showed the antimicrobial effect of a
Lactobacillus (not precisely identied). GORBACH (1987) was able to heal a
very persistent colitis caused by Clostridium difficile with a Lactobacillus. (Infections
of Clostridium difficile often develop on treatment with
antibiotics as these have the unfavourable side effect of eliminating the natural
gut flora, thus preparing the ground for Clostridium infections).
That the antibacterial effect is based on excretions of lactobacteria was confirmed
by MICHETTI (1999) who could heal Helicobacter pylori infections
with the supernatant layer of a whey culture of Lactobacillus acidophilus. Lactobacteria activate makrophages (SATO,
1988), through the bakteriocins or
via other mechanism. The strengthening of the immune system may also be the cause
of the well proven but not properly understood anticarcinogenic effect
of probiotic bacteria (GRAEME, 1996).
In the manufacture of
the fermented soymilk product (commercial names: "Gastrosan" or
"Gastropharm") the high proteolytic activity of Lactobacillus
bulgaricus is utilized. Gastrosan is something of a vegan yoghurt produced by %
protein derivates and about 15% lactic acid. The protein is partly
hydrolysed, it consists of longer of shorter peptide chains and contains also free
amino acids; in addition one may assume that small quantities of
Lactobacillus bacteriocin are present ("Lactocin"). The soy protein hydrolysate
has also an acid buffering capacity on account of the amino
groups released during hydrolysis.
Gastrosan was
tested for its gastroprotective effect in animal experiments (TASKOV, 1981). For
a more detailed investigation a placebo controlled
clinical study was carried out at the Clinical Center for Gastroenterology in Sofia
(STOYNOV, 1999).
Purpose of the
study was to investigate the
- Influence of the
product on clinical symptoms in cases of duodenal ulcer.
- Epithelialization
of ulcer lesions in the duodenum
- Influence on
Helicobacter pylori infections.
The clinical
symptons (heart burn, nausea, vomiting) improved after four weeks with all
patients with a significantly better result in the verum group
as compared to the placebo group (80% versus 46,6%, 30 persons in each group). This
effect is among others ascribed to the buffer capacity of the
partly hydrolysed protein.Gastroscopies carried out in the beginning and at the
end of the study showed a complete epithelialization in 43.3% of the patients
of the verum group (as opposed to 23,3% in the placebo group), a partial
epithelialization with 40% of the patients of the verum group (versus 33,4% in
case of the placebo group).A beneficial effect was also observed for stomachial
mucous membrane erosion and gastritis symptoms.
Of particular
interest are the findings concerning the Helicobacter pylori
infections. 83% of patients had such an infection before the study and this figure
did not change significantly neither in the verum nor the placebo
group. What changed was the intensity of the infection (measured by the Chan index)
which diminished significantly in the verum group and which remained
practically unchanged in the placebo group.The causality of Helicobacter pylori
in the ulcer development is known. But
it is also known that its simple presence in the guts as a commensal microorganism
is not sufficient for the generation of an ulcer, rather the
ulcus development appears to be the consequence of a sudden increase of Helicobacter
virulence and toxicity. Colonizations by Helicobacter were
formerly considered normal, practically 100% of the population were affected without
showing clinical symptoms. Thus, Helicobacter may be considered a
part of the natural gut flora, it may even have a beneficial effect (probiotic).
LABENZ (1997) found that the elimination of Helicobacter pylori
lead to increased reflux oesophagitis (heart burn). In this respect the decrease
of the intensity of virulence and toxicity of Helicobacter without
its complete eradication is a very desireable effect of Gastrosan.
References
GORBACH, S., et
al., 1987: Successful treatment of relapsing of Clostridiumdifficile colitis
with Lactobacillus GG. Lancet1, 1987, 11 1519-1521
GRAEME, H. Mc.,
1996: Probiotics and colon cancer prevention. Asia Pacific J Clin Nutr (1996)
5: 48-52
LABENZ, J. et al.,
1997: Curing Helicobacter pylori infection in patients with duodenal ulcer may
provoke reflux esophagitis. Gastroenterology 1997;
112: 1442-1447.
MICHETTI, P. et
al., 1999: Effect of Whey-based culture supernatant of Lactobacillus
acidophilus (johnsonii) La1 on Helicobacter pylori infection in
humans. Digestion 1999; 60: 203-209.
MONTVILLE, T.J.,
KAISER A.L., 1993: Antimicrobial Proteins: "Classification, Nomenclature, Diversity,
and Relationship to Bacteriocins" in Bacteriocins of
Lactic Acid Bacteria, Academic Press Inc.
SATO, K. et al.
1988: Enhancement of host resistance against Listeria infection by
Lactobacillus casei: Activation of liver macrophages and
peritoneal macrophages by Lactobacilus casei. Microbiol. Immunol. 32, 1988, 5,
689-698
SILVA, M., et al.,
1987: Antimicrobial substance from human lactobacillus strain. Antimicrobial
Agents Chemotherapy, 31, 1987, 11, 1231-33
STOYNOV, S., et al.
1999: Clinical study on Gastropharm(R) tablets in patients with duodenal ulcer.
(Copies of te study are avalable on request).
TASKOV, M. et al.,
1981: Studies on the effect of Gastropharm on the gastrointestinal tract. Developments
of the Scientific Institute for Chemical
and Pharmaceutical Research. Sofia, Bulgarien, Vol. XI, 1981, 235-9