Intestinal bacteria Lactobacilli

Chitooligomers set free by hydrolases become carbon sources for the growth of intestinal bacteria. Lactobacillus lactis utilizes the oligomers (GlcNAc)i-6, the monomer and dimer being bifidogenic substances [261 -263]. 

The ability to hydrolyze the peptide bond in conjugated bile acids (Fig. 1) is widely distributed among intestinal bacteria. Conjugated bile acid hydrolase (CBH) (EC 3.5) activity has been detected in members of the genera Bacteroides, Bifidobacterium, Fusobacterium, Clostridium, Lactobacillus, Peptostreptococcus and Streptococcus [13-17]. However, there is considerable variation in occurrence of this enzymatic activity among species and strains. 

The chicken intestinal microbiota is composed principally of Gram-positive bacteria (Gong et al., 2002). The lactobacilli are predominant in the small intestine (with smaller numbers of streptococci and enterobacteria), whereas the caecal flora is composed mainly of anaerobes and fewer numbers of facultative bacteria. Predominant cultured flora of the ileum of chicken include Lactobacillus, Streptococcus, E. coli and Eubacterium, while Eubacterium and Bacteroides dominated the caecum flora. 

Bernet, M. F., Brassart, D., Neeser, J. R., and Servin, A. L. (1994). Lactobacillus acidophilus Lai binds to cultured human intestinal cell lines and inhibits cell attachment and cell invasion by enterovirulent bacteria. Gut 35, 483-489. 

Bacteria that Produce Histidine Decarboxylase. Early studies demonstrated that histidine decarboxylase is widely distributed in the genera Escherichia, Salmonella, Clostridium, Bacillus and Lactobacillus (24). Evidence for the enzyme in E, coli included the finding by Gale (7) that 14 of 155 cultures possessed histidine decarboxylase. A study by Hanke and Koessler (25) found that six of 20 coliform cultures synthesized the enzyme. Havelka (26) found that 71.4% of all Enterobacteriacae isolated from imported marine fish produced histamine. Eggerth (27) found 40 strains of bacteria of intestinal origin capable of decarboxylating histidine. Rodwell (11) found various... 

Pharmacologically active compounds of microbial origin are not limited to antibiotics. Viable or dead microorganisms are used as antigens and toxin-formers for the production of antibodies and antitoxins. Pathogenic bacteria are mass-produced in surface and submerged cultures for vaccine production. Special bacteria are used in the form of oral medication. For example, viable cells of Lactobacillus and Escherichia coli are employed in the treatment of maladjusted intestinal microflora 30). 

Probiotics (literally, replacing bad germs with good ones) have been studied. For example, lactic acid-producing bacteria such as Lactobacillus acidophilus, which acidifies the intestinal contents and is a normal inhabitant of the human intestine, have been used in the treatment of vaginal and gastrointestinal disorders. 

The normal balance of intestinal flora may be maintained or restored to normal from an unbalanced state by a well-balanced diet or by oral bacteriotherapy. Oral bacteriotherapy, using intestinal strains of lactic acid bacteria (LAB), such as Lactobacillus and Bifidobacterium, can restore normal intestinal balance and produce beneficial effects. 

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