392
Consumption of unfermented milk such as yogurt shows fewer symptoms in lactose-intolerant individuals than nonfermented dairy products. Yogurt helps in the
digestion of lactose because of the lactase produced by lactic acid bacteria (LAB)
such as L. acidophilus and Bifidobacterium (Fernandez et al. 2003). Various species
of Lactobacillus were reported to have pharmacological importance, such as L.
reuteri for acute diarrhea (Shornikova et al. 1997a, 1997b) and gastroenteritis
(Marteau et al. 2001), L. salivarius for eradication of Helicobacter pylori (Aiba et al.
1998), and L. rhamnosus for enhanced cellular immunity (Tomioka et al. 1992).
Prebiotics and probiotics can influence fermentation in the colon, thereby
increasing bacterial mass and the water-binding capacity of stool. Stool frequency
may be increased, resulting in reduced levels of polyamines and harmful metabolites such as indoles that cause colon cancer and decreased polyps, as reported by
Gorbach et al. (1987). Probiotic microbiota can also prevent urogenital infection
caused by pathogens such as Klebsiella pneumoniae and Pseudomonas aeruginosa
(Sanders and Klaenhammer 2001). Reduced serum cholesterol was reported by
Ouwehand et al. (2002) with the apt use of probiotics.
Lactobacillus plantarum is reported to reduce inflammation in the bowel
(Vanderhoof 2000) and pouchitis (Schultz and Sartor 2000). Probiotic-induced
reduction in pain, constipation, and bloating was also reported in experimental tests
(Nobaek et al. 2000). Vanderhoof (2000) reported reduced recurrence of Clostridium
difficile-induced diarrhea in the presence of Saccharomyces boulardii (Pochapin
2000). The synergic effect of Clostridium difficile with Klebsiella oxytoca reduces
antibiotic-associated diarrhea (Marteau et al. 2001)
The action of the immune system is extremely complex and involves both antibody- and cell-based reactions against pathogens. Cancer, AIDS, leukemia, etc.,
and normal conditions such as old age or pregnancy, can cause immunodeficiency
symptoms or autoimmune diseases such as allergies and inflammatory bowel disease (Perdigon et al. 1995; Dugas et al. 1999). Probiotic microflora could target
intestinal epithelial cells, lymphocytes, and blood leukocytes, and lactobacilli
adhered to epithelial cells of the intestine activate cytokines, immunoglobulins,
interferons, and macrophages.
Cells of the innate immune system provide early protection for the host by reacting rapidly to challenges by infectious agents, resulting in a cascade of events to
eliminate the invading pathogenic agent that involves phagocytic cells such as neutrophils, macrophages, and monocytes. Consumption of probiotic products initiates
a host response by interacting with intestinal enterocytes, and intestinal cells when
stimulated by bacteria produce various immunomodulatory molecules. It was
reported that some probiotic organisms can modulate the in vitro expression of proand antiinflammatory molecules in a strain-dependent manner. Probiotics such as
Lactobacillus sakei and L. johnsonii induce the expression of interleukin and tumor
necrosis factor, respectively, by interaction between leukocytes and epithelial cells
(Haller et al. 2000).
Many probiotic strains can influence phagocytosis. Lactobacillus species such as
L. acidophilus and L. casei can stimulate the immune system by increasing phagocytosis (Perdigon et al. 1988). L. rhamnosus in fermented food upregulates the
T.S. Swapna et al.
Consumption of unfermented milk such as yogurt shows fewer symptoms in lactose-intolerant individuals than nonfermented dairy products. Yogurt helps in the
digestion of lactose because of the lactase produced by lactic acid bacteria (LAB)
such as L. acidophilus and Bifidobacterium (Fernandez et al. 2003). Various species
of Lactobacillus were reported to have pharmacological importance, such as L.
reuteri for acute diarrhea (Shornikova et al. 1997a, 1997b) and gastroenteritis
(Marteau et al. 2001), L. salivarius for eradication of Helicobacter pylori (Aiba et al.
1998), and L. rhamnosus for enhanced cellular immunity (Tomioka et al. 1992).
Prebiotics and probiotics can influence fermentation in the colon, thereby
increasing bacterial mass and the water-binding capacity of stool. Stool frequency
may be increased, resulting in reduced levels of polyamines and harmful metabolites such as indoles that cause colon cancer and decreased polyps, as reported by
Gorbach et al. (1987). Probiotic microbiota can also prevent urogenital infection
caused by pathogens such as Klebsiella pneumoniae and Pseudomonas aeruginosa
(Sanders and Klaenhammer 2001). Reduced serum cholesterol was reported by
Ouwehand et al. (2002) with the apt use of probiotics.
Lactobacillus plantarum is reported to reduce inflammation in the bowel
(Vanderhoof 2000) and pouchitis (Schultz and Sartor 2000). Probiotic-induced
reduction in pain, constipation, and bloating was also reported in experimental tests
(Nobaek et al. 2000). Vanderhoof (2000) reported reduced recurrence of Clostridium
difficile-induced diarrhea in the presence of Saccharomyces boulardii (Pochapin
2000). The synergic effect of Clostridium difficile with Klebsiella oxytoca reduces
antibiotic-associated diarrhea (Marteau et al. 2001)
The action of the immune system is extremely complex and involves both antibody- and cell-based reactions against pathogens. Cancer, AIDS, leukemia, etc.,
and normal conditions such as old age or pregnancy, can cause immunodeficiency
symptoms or autoimmune diseases such as allergies and inflammatory bowel disease (Perdigon et al. 1995; Dugas et al. 1999). Probiotic microflora could target
intestinal epithelial cells, lymphocytes, and blood leukocytes, and lactobacilli
adhered to epithelial cells of the intestine activate cytokines, immunoglobulins,
interferons, and macrophages.
Cells of the innate immune system provide early protection for the host by reacting rapidly to challenges by infectious agents, resulting in a cascade of events to
eliminate the invading pathogenic agent that involves phagocytic cells such as neutrophils, macrophages, and monocytes. Consumption of probiotic products initiates
a host response by interacting with intestinal enterocytes, and intestinal cells when
stimulated by bacteria produce various immunomodulatory molecules. It was
reported that some probiotic organisms can modulate the in vitro expression of proand antiinflammatory molecules in a strain-dependent manner. Probiotics such as
Lactobacillus sakei and L. johnsonii induce the expression of interleukin and tumor
necrosis factor, respectively, by interaction between leukocytes and epithelial cells
(Haller et al. 2000).
Many probiotic strains can influence phagocytosis. Lactobacillus species such as
L. acidophilus and L. casei can stimulate the immune system by increasing phagocytosis (Perdigon et al. 1988). L. rhamnosus in fermented food upregulates the
T.S. Swapna et al.