Bifidobacteria intestinal microflora

Intestinal Metabolism Intestinal drug metabolism can occur by microflora present in the gut lumen, as well as by enzymes present in luminal fluids and in the intestinal mucosa [166], Metabolism of xenobiotics by gut microflora is low in comparison to metabolism by the gut mucosa and liver [62], However, the intestinal microflora (e.g., Bacteroides and Bifidobacteria) may play an important role in the first-pass metabolism of compounds that are poorly or incompletely absorbed by the gut mucosa, especially in the lower parts of the intestine. This bacterial metabolism is largely degradative,... 

Oligofructose and inulin are known to lower plasma LDL cholesterol, but their mode of action does not involve inhibiting cholesterol absorption (Beylot, 2005 Kaur and Gupta, 2002). As mentioned earlier, oligofructose and inulin are not viscous fibers but rather serve as excellent fuel sources for beneficial intestinal bacteria, particularly lactobacilli and bifidobacteria (Boeckner et al., 2001). In this way, changes in intestinal microflora induced... 

It has been shown that bifidobacteria and lactobacillus protect infants from pathogenic intestinal microorganisms and therby decrease the incidence of infantile diarrhea (Yoshioka et al. 1983 Huang et al. 2002). They are associated with a higher production of short-chain fatty acids (acetic and lactic acids), which are a source of energy for colonocytes. Furthermore, strains of bifidobacteria and lactobacillus influence gut maturation processes in infants and have anti-inflammatory effects (Hedin et al. 2007). Specific components of the intestinal microflora, including Lactobacilli and Bifidobacteria, are beneficial for the host, such as... 

Comparison of the data on the qualitative and quantitative composition of the fecal microflora of the two groups of subjects showed a significant increase on the number of bifidobacteria. Gram-positive anaerobic cocci, coliforms and total aerobes in the feces of the treated patients (Figure 1). However, these alterations do not represent a substantial modification of the intestinal microflora composition. 

According to this definition the safety and efficacy of probiotics must be scientifically demonstrated. However, as different probiotics may interact with the host in different manners, their properties and characteristics should be well defined. It is understood that probiotic strains, independent of genera and species, are unique and that the properties and human health effects of each strain must be assessed in a case-by-case manner. Most probiotics are currently either lactic acid bacteria or bifidobacteria, but new species and genera are being assessed for future use. The probiotic bacteria in current use have been isolated from the intestinal microflora of healthy human subjects of long-standing good health and thus most of them are also members of the healthy intestinal microflora. 

The development of the intestinal microbiota needs to be characterized to define the composition that helps us to remain healthy. Specific aberrations in the intestinal microflora may predispose to disease. Such aberrations have been identified in allergic disease, including decreased numbers of bifidobacteria and an atypical composition of bifidobacterial microflora. Also, aberrations in Clostridium content and composition have been reported to be important. Similar predisposing factors may also exist in the case of microflora and both inflammatory gut diseases and rotavirus diarrhea. Microflora aberrations have also been reported in rheumatoid arthritis, juvenile chronic arthritis, ankylosing spondylitis, and irritable bowel syndrome patients. A thorough knowledge of the intestinal microflora composition will offer a basis for future probiotic development and the search for new strains for human use. Many diseases and their prevention can be linked to the microflora in the gut. 

Benno Y and Mitsuoka T (1986) Development of intestinal microflora in humans and animals. Bifidobacteria Microflora 5 13-25. 

The effects of dietary FOS on the GI microflora of poultry are well documented. Flidaka et ol. (1991) found that consumption of 8 g FOS per day increased numbers of bifidobacteria, improved blood lipid profiles and suppressed putrefactive substances in the intestine. Patterson et d. (1997) found that caecal bifidobacteria concentrations increased 24-fold and lactobacilli populations increased 7-fold in young broilers with FOS. Bifidobacteria may inhibit other microbes because of a high production of volatile fatty acids (VFAs) or the secretion of bacteriocin-like peptides (Burel and Valat, 2007). The improvement in gut health status by dietary FOS supplementation often results in improved growth performance. Ammerman et d. (1988) demonstrated that the addition of dietary FOS at a level of 2.5 or 5.0g/kg diet improved feed efficiency over the period from 1 to 46 days of age. Mortality was reduced with the higher level. However, Waldroup et d. (1993) found that supplementing the diet of broilers with 3.75 g/kg FOS had few consistent effects on production parameters or carcass Sdmonella concentrations. 

Probiotic supplements contain viable bacteria (e.g., bifidobacteria and lactobacilli), designed to shift the balance of the microflora in the large intestines to the detriment of harmful bacteria. Probiotics can contain prebiotics as substrates (synbiotics), while prebiotics can be administered alone to promote endogenous populations of bifidogenic or lactic acid bacteria. These represent a... 

Among Finnish infants the bacterial cellular fatty acid profile in faecal samples differed significantly between infants in whom atopy was and was not developing. Atopic subjects had more Clostridia and fewer Bifidobacteria. The differences in neonatal gut microflora precede the expression of atopy, suggesting a crucial role of the balance of indigenous intestinal bacteria for the maturation of human immunity to a non-atopic mode [ 180(IIIC)]. 

Microbial numbers and species diversity increases in the distal small intestine, with facultative anaerobes as well as more strict anaerobic species such as bacteroides, clostridia. Gram positive cocci and bifidobacteria reaching population levels of up to 10 colony forming units (CFU)/mL contents. The colon is the main site of microbial colonization in the gut, and the microflora is dominated by the strict anaerobes. This microflora is made up of Bacteroides spp., Eubacterium spp., Clostridium spp., Eusobacterium spp, Peptostreptococcus spp., and Bifidobacterium spp., with lower population levels of anaerobic streptococci, lactobacilli, methanogens and sulphate-reducing bacteria (Figure 6.2). Climax microbial populations occur (up to 10 cells/g) and estimates of diversity range from 400 to 500 different bacterial species. The facultative anaerobes such as lactobacilli, streptococci/enterococci and the Enterobacteriaceae occur in population levels about 100-1000-fold lower than strict anaerobes (Moore and Holdeman 1975 Conway 1995). 

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