Ecology of Bifidobacterium in the Human Intestinal Flora

Mutai, Masahiko; Tanaka, Ryuichiro

doi:10.12938/bifidus1982.6.2_33

Cited by 65 publications

(58 citation statements)

References 23 publications

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“…The levels of faecal lactobacilli observed in the present study were high as those reported in previous studies (Hill et al, 1971;Yamagishi et al, 1974;Simon & Gorbach, 1984;Faassen et al, 1987;Mutai & Tanaka, 1987; Lidbeck, Table 3 Immunological parameters (meanAE s.e.m.) measured at the end of the stabilisation period (week 2), after 2 and 4 weeks during the test period (week 4 and week 6), and at the end of the follow-up period (week 8) a For IFNg and IL-2 production mononuclear cells were stimulated with ConA 20mgaml and for IL-1b production with LPS 100mgaml during 24h.…”

Section: Discussionsupporting

confidence: 82%

The effect of consumption of milk fermented by Lactobacillus casei strain Shirota on the intestinal microflora and immune parameters in humans

1998

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Objective: To determine the effect of consumption of milk fermented by Lactobacillus casei strain Shirota (L. casei Shirota) on the composition and metabolic activities of the intestinal micro¯ora, and immune parameters in humans. Subjects: Twenty healthy male subjects aged 40±65 years were selected. Design: A placebo-controlled trial was performed in which 10 subjects were randomly assigned to a control and 10 to a treatment group. During the ®rst and last two weeks of the 8-week study the subjects received a strictly controlled diet without fermented products. The same controlled diet was given during the intermediate 4-week test period but then the treatment group received three times daily 100 ml of fermented milk containing 10 9 CFU L. casei Shirotaaml, whereas the same amount of unfermented milk was given to the subjects in the control group. Results: In comparison to the control group, the consumption of L. casei Shirota-fermented milk resulted in an increase of the Lactobacillus count in the faeces in which the administered L. casei Shirota was predominant at the level of 10 7 CFUag wet faeces. This was associated with a signi®cant increase in Bi®dobacterium counts (P`0.05). Some shifts in the other bacterial species were found, such as a decreased number of Clostridium; however the differences were not statistically different between the treatment and the control groups.The b-glucuronidase and b-glucosidase activities per 10 10 bacteria decreased signi®cantly (P`0.05) at the second week of the 4-week test period with the consumption of L. casei Shirota-fermented milk. Furthermore, the consumption of the fermented milk product resulted in a slight but signi®cant increase in the moisture content of the faecal samples (P`0.05). No treatment effects were observed for any of the immune parameters measured (including natural killer (NK) cell activity, phagocytosis and cytokine production). Conclusions:The results suggest that consumption of L. casei Shirota-fermented milk is able to modulate the composition and metabolic activity of the intestinal¯ora and indicate that L. casei Shirota-fermented milk does not in¯uence the immune system of healthy immunocompetent males.

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Section: Discussionsupporting

confidence: 82%

The effect of consumption of milk fermented by Lactobacillus casei strain Shirota on the intestinal microflora and immune parameters in humans

1998

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“…The intestinal microflora plays several significant roles in the digestion of food, metabolism of endogenous and exogenous compounds, immunopotentiation, and prevention of colonization by pathogens in the gastrointestinal tract and hence is involved in maintaining human health (8,36). The gut microflora has been investigated in great detail by using anaerobic culture techniques (5,21,(23)(24)(25). The predominant genera in the large bowel are reported to be Bacteroides, Eubacterium, Clostridium, Ruminococcus, Peptococcus, Peptostreptococcus, Bifidobacterium, and Fusobacterium.…”

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confidence: 99%

Development of 16S rRNA-Gene-Targeted Group-Specific Primers for the Detection and Identification of Predominant Bacteria in Human Feces

Matsuki

Watanabe

Fujimoto

et al. 2002

Appl Environ Microbiol

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580

300

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For the detection and identification of predominant bacteria in human feces, 16S rRNA-gene-targeted groupspecific primers for the Bacteroides fragilis group, Bifidobacterium, the Clostridium coccoides group, and Prevotella were designed and evaluated. The specificity of these primers was confirmed by using DNA extracted from 90 species that are commonly found in the human intestinal microflora. The group-specific primers were then used for identification of 300 isolates from feces of six healthy volunteers. The isolates were clearly identified as 117 isolates of the B. fragilis group, 22 isolates of Bifidobacterium, 65 isolates of the C. coccoides group, and 17 isolates of Prevotella, indicating that 74% of the isolates were identified with the four pairs of primers. The remaining 79 isolates were identified by 16S ribosomal DNA sequence analysis and consisted of 40 isolates of Collinsella, 24 isolates of the Clostridium leptum subgroup, and 15 isolates of disparate clusters. In addition, qualitative detection of these bacterial groups was accomplished without cultivation by using DNA extracted from the fecal samples. The goal for this specific PCR technique is to develop a procedure for quantitative detection of these bacterial groups, and a real-time quantitative PCR for detection of Bifidobacterium is now being investigated

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“…Our data allowed us to confirm the validity of most of the Bzjidobacterium species which we studied and to identify some classification errors. Finally, our results showed that Bifidobacterium strains have no tRNA genes in the 16s-23s spacer region.Members of the genus Bijidobacterium are widespread in nature, and the habitats of these organisms range from sewage (53, 54) to human and animal intestines (28,31,44,52,56). The ability to catabolize hexose by a particular pathway via fructose phosphate phosphoketolase is important for recognizing members of this genus (8, 51).…”

mentioning

confidence: 99%

“…Members of the genus Bijidobacterium are widespread in nature, and the habitats of these organisms range from sewage (53,54) to human and animal intestines (28,31,44,52,56). The ability to catabolize hexose by a particular pathway via fructose phosphate phosphoketolase is important for recognizing members of this genus (8, 51).…”

mentioning

confidence: 99%

16S rRNA and 16S to 23S Internal Transcribed Spacer Sequence Analyses Reveal Inter- and Intraspecific Bifidobacterium Phylogeny

Leblond‐Bourget

Piégay

Mangin

et al. 1996

International Journal of Systematic Bacteriology

189

132

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In the last few years many attempts have been made to differentiate more than 20 Bijidobacteriurn species. It has been recognized that identification of bifidobacterial species is problematic because of phenetic and genetic heterogeneities. In order to contribute to our understanding of BiJdobacterium taxonomy, we studied Bijidobacterium phylogeny by performing both 16s rRNA and 16s to 23s (16s-23s) internally transcribed spacer (ITS) sequence analyses. In this study, we determined 16s rRNA sequences of five Bifidobacteriurn strains representing four species, and compared them with the sequences available in the GenBank database, and used them to construct a distance tree and for a bootstrap analysis. Moreover, we determined the ITS sequences of 29 bifidobacterial strains representing 18 species and compared these sequences with each other. We constructed a phylogenetic tree based on these sequence data and compared this tree with the tree based on 16s rRNA sequence data. We found that the two trees were similar topologically, suggesting that the two types of molecules provided the same kind of phylogenetic information. However, while 16s rRNA sequences are a good tool to infer interspecific links, the 16s-23s rDNA spacer data allowed us to determine intraspecific relationships. Each of the strains was characterized by its own ITS sequence; hence, 16s-23s rRNA sequences are a good tool for strain identification. Moreover, a comparison of the ITS sequences allowed us to estimate that the maximum level of ITS divergence between strains belonging to the same species was 13%. Our data allowed us to confirm the validity of most of the Bzjidobacterium species which we studied and to identify some classification errors. Finally, our results showed that Bifidobacterium strains have no tRNA genes in the 16s-23s spacer region.Members of the genus Bijidobacterium are widespread in nature, and the habitats of these organisms range from sewage (53, 54) to human and animal intestines (28,31,44,52,56). The ability to catabolize hexose by a particular pathway via fructose phosphate phosphoketolase is important for recognizing members of this genus (8, 51). In the last few years many ways to differentiate Bifidobacterium species have been developed. Numerical taxonomy analysis, which requires data for many characteristics, has been used to circumscribe clusters and to describe strains. Morphological traits, carbohydrate metabolism data, DNA G + C contents (3), electrophoretic patterns (22,48,50), serologic data (44, 58, 59), cell wall compositions (22), and rRNA gene restriction patterns (26) have been used to subdivide Bifidobacterium species (for a review, see reference 3). Major advances in our understanding of the taxonomy of members of the genus Bijidobacterium have come from the DNA-DNA hybridization studies performed by Scardovi et al. (49,54,55,57). However, problems with the identification of Bijidobacterium species are compounded by evidence that there is phenotypic and genetic heterogeneity in these species (6). Moreo...

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Ecology of Bifidobacterium in the Human Intestinal Flora

Cited by 65 publications

References 23 publications

The effect of consumption of milk fermented by Lactobacillus casei strain Shirota on the intestinal microflora and immune parameters in humans

The effect of consumption of milk fermented by Lactobacillus casei strain Shirota on the intestinal microflora and immune parameters in humans

Development of 16S rRNA-Gene-Targeted Group-Specific Primers for the Detection and Identification of Predominant Bacteria in Human Feces

16S rRNA and 16S to 23S Internal Transcribed Spacer Sequence Analyses Reveal Inter- and Intraspecific Bifidobacterium Phylogeny

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