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Yoshimi Benno

Publications and source records attributed to Yoshimi Benno.

At least 55 records · Page 3Linked to original sources
PubMed2004

[Application of particular human fecal microbiota profile for disease precaution].

By a sequence analysis of 16S rDNA sequences libraries, the whole structure of human fecal microbiota has emerged. Among a total of 744 clones isolated from fecal specimens of three healthy adults, approximately 25% belonged to 31 known species. Seventy-five percent of the remaining clones were novel "phylotypes". The 16S rDNA libraries included the Bacteroides group, the Streptococcus group, the Bifidobacterium group, and the Clostridium rRNA clusters IV, IX, XIVa, and XVIII. From the results, marked individual differences in the composition of human fecal microbiota were found. Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to characterize and compare human fecal microbiota among individuals. By T-RFLP, the differential profiles of fecal microbiota among individuals were noted. The species composition of fecal bifidobacteria among individuals was stable. Molecular analysis of fecal microbiota could be used for disease precaution.

Adult↗
PubMed2003

Performance of bifidobacteria in oat-based media.

Thirteen Bifidobacterium strains were isolated form the faeces of healthy elderly subjects. The ability of the isolated strains to acidify and survive in an oat-based medium was assessed and compared to a commercial starter Bifidobacterium strain. Since adhesion to the intestinal mucosa is one of the main selection criteria for potential probiotics, the influence of the oat medium on the ex vivo adhesion of the isolates to both human colonic tissue and to mucus from elderly subjects was assessed. Seven of the fourteen strains survived the 24-h fermentation, six of these acidified the medium to below pH 5. Supplementation of the medium with soy protein had a negative effect on survival and the acidification. The strains isolated from the elderly subjects were found to adhere in high levels to immobilised intestinal mucus from elderly. However, their adhesion to colonic tissue was significantly lower. Prior exposure to the oat-based medium increased the adhesion of two of the strains.

Aged↗
PubMed2003

Expression of Ruminococcus albus xylanase gene ( xynA) in Streptococcus bovis 12-U-1.

The objective of this study was to ligate the xylanase gene A ( xynA) isolated from Ruminococcus albus 7 into the promoter and signal-peptide region of the lichenase [beta-(1,3-1,4)-glucanase] gene of Streptococcus bovis JB1. This fusion gene was inserted into the pSBE11 vector, and the resulting recombinant, plasmid pXA, was used to transform S. bovis 12-U-1 cells. The transformant, S. bovis 12UXA, secreted the xylanase, which was stable against freeze-thaw treatment and long-time incubation at 37 degrees C. The introduction of pXA and production of xylanase did not affect cell growth, and the xylanase produced degraded xylan from oat-spelt and birchwood.

Biodegradation, Environmental↗
PubMed2003

Application of terminal RFLP analysis to characterize oral bacterial flora in saliva of healthy subjects and patients with periodontitis.

Terminal restriction fragment-length polymorphism (T-RFLP) analysis was applied to characterize oral bacterial flora in saliva from 18 healthy subjects and 18 patients with periodontitis. The 16S rRNA genes (rDNAs) of oral bacteria and spirochaetes in saliva were amplified by PCR with a 6'carboxy-fluorescein (6-FAM)-labelled universal forward primer (27F) and a universal reverse primer (1492R) or the Spirochaeta-selective reverse primer. The 16S rDNAs were digested with restriction enzymes with 4 bp recognition sites (HhaI or MspI) and analysed by using an automated DNA sequencer. T-RFLP patterns were numerically analysed using a computer program. From analysis of the oral bacterial community, patterns derived from periodontally healthy subjects and patients with periodontitis were grouped into different clusters, though with some uncertainty. Samples from patients with periodontitis tended to cluster into their respective types (aggressive and chronic periodontitis), although this was not very clear. Analysis of spirochaetal community using T-RFLP showed that the patterns derived from patients with periodontitis were grouped more as compared with the analysis of the oral bacterial community. These results suggest that samples from patients with periodontitis contain an unexpected diversity. T-RFLP patterns of 16S rDNAs from saliva samples of two periodontally healthy subjects over a 5-week period showed host-specific relatively stable oral bacterial flora. Our study indicates that T-RFLP analysis is useful for the assessment of diversity of oral bacterial flora and rapid comparison of the community structure between subjects with and without periodontitis.

Adult↗
PubMed2003

Terminal restriction fragment length polymorphism analysis for human fecal microbiota and its application for analysis of complex bifidobacterial communities.

Terminal restriction fragment length polymorphism (T-RFLP) analysis was used to characterize and compare human fecal microbiota among individuals. T-RFLP patterns of fecal 16S ribosomal DNA (rDNA) PCR products from three adults revealed host-specific bacterial communities and were in good agreement with those reported in our previous study. In addition, we applied T-RFLP analysis for the analysis of complex bifidobacterial communities in human fecal samples. The developed method based on Bifidobacterium genus-specific PCR and T-RFLP could identify more than one bifidobacterial species. T-RFLP patterns of Bifidobacterium genus-specific PCR products from the fecal samples were host-specific as well as those of fecal 16S rDNA PCR products. These results were confirmed by PCR-denaturing gradient gel electrophoresis (DGGE) with primers specific for the genus Bifidobacterium and Bifidobacterium species- and group-specific PCR. Our study demonstrates that T-RFLP analysis is useful for assessment of the diversity of the human fecal microbiota and rapid comparison of the community structure among individuals, and that the applied method is useful for rapid and sensitive analysis of bifidobacterial community.

Adult↗
PubMed2003

Molecular analysis of fecal microbiota in elderly individuals using 16S rDNA library and T-RFLP.

Fecal microbiota in six elderly individuals were characterized by the 16S rDNA libraries and terminal restriction fragment length polymorphism (T-RFLP) analysis. Random clones of 16S rRNA gene sequences were isolated after PCR amplification with universal primer sets from total genomic DNA extracted from feces of three elderly individuals. These clones were partially sequenced (about 500 bp). T-RFLP analysis was performed using 16S rDNA amplified from six subjects. The lengths of the terminal restriction fragment (T-RF) were analyzed after digestion by HhaI and MspI. Among 240 clones obtained, approximately 46% belonged to 27 known species. About 54% of the other clones were 56 novel "phylotypes" (at least 98% homology of clone sequence). These libraries included 83 species or phylotypes. In addition, about 13% (30 phylotypes) of these phylotypes were newly discovered in these libraries. A large number of species that are not yet known exist in the feces of elderly individuals. 16S rDNA libraries and T-RFLP analysis revealed that the majority of bacteria were Bacteroides and relatives, Clostridium rRNA cluster IV, IX, Clostridium rRNA subcluster XIVa, and "Gammaproteobacteria". The proportion of Clostridium rRNA subcluster XIVa was lower than in healthy adults. In addition, although Ruminococcus obeum and its closely related phylotypes were detected in high frequency in healthy young subjects, hardly any were detected in our elderly individuals. "Gammaproteobacteria" were detected at high frequency.

Aged↗
PubMed2003

Impact of two probiotic Lactobacillus strains feeding on fecal lactobacilli and weight gains in chicken.

Two probiotic strains, Lactobacillus agilis JCM 1048 and L. salivarius subsp. salicinius JCM 1230 isolated from chicken intestine, exhibited probiotic characteristics that can be applied for chicken production. After 7 days of probiotic feeding (FD7), the count of intestinal lactobacilli in the probiotic group (group P, n=10) was significantly (p<0.05) higher than that in the control group (group C, n=9). After 40 days of probiotic feeding (FD40), the lactobacilli and enterococci counts were stable but the Enterobacteriaceae number was significantly reduced (p<0.05). A total of 163 isolated lactobacilli were identified as the L. acidophilus/gallinarum group (49.7%), L. agilis (30.7%), L. salivarius (9.2%), L. reuteri (9.2%), and Lactobacillus spp. (1.2%). The probiotic lactobacilli positively affected the Lactobacillus biota in chickens at FD7, with a significant increase in the number (p<0.05) of L. agilis and group P. The viable counts of each Lactobacillus species at FD40, however, showed no differences between two groups. An increasing incidence of L. agilis was also noted with probiotic feeding. The probiotic effect of two strains resulted in significantly increased weight gains (10.7%) of group P in comparison with group C at FD40 (p<0.01).

Animal Feed↗
PubMed2002

Detection of novel oral phylotypes associated with periodontitis.

A phylogenetic approach based on 16S rRNA (rDNA) has been recently applied to investigate the diversity of cultivable and uncultivable species in the human oral cavity without cultivation. In a previous study [Sakamoto et al. (2000) Microbiol. Immunol. 44, 643-652], we identified a number of novel oral phylotypes, representing as yet uncultured organisms. The purpose of this study was to design specific PCR primers for five phylotypes AP12, AP21, AP24, AP50, and RP58, which are deeply branched particularly in the phylogenetic tree, and determine the prevalence of these phylotypes in 45 patients with periodontitis and 18 healthy subjects. The specificity of each primer was validated by the sequence analysis of PCR products obtained from saliva and subgingival plaque samples. Among phylotypes tested, phylotype AP24, which is closely related to oral clone DA014 reported previously [Paster et al. (2001) J. Bacteriol. 183, 3770-3783], was significantly associated with saliva and subgingival plaque samples from patients with periodontitis (P<0.01), but the difference was not statistically significant in the presence of other phylotypes. These data suggest that phylotype AP24 may play an important role in periodontal disease.

Base Sequence↗
PubMed2002

Stability of species composition of fecal bifidobacteria in human subjects during fermented milk administration.

Bifidobacteria play important roles in human health. However, the influence of exogenous factors on species composition of fecal bifidobacteria is still unclear. The objective of this study was to investigate the effects of fermented milk administration on the species composition of fecal bifidobacteria by molecular biological methods. Fermented milk containing Lactobacillus helveticus was given to seven healthy subjects, and the probiotic effect on human fecal microflora was demonstrated as a significant increase of bifidobacteria and decrease of clostridia by the conventional culture method. Species composition of bifidobacteria in the human fecal microflora was then investigated directly in fecal specimens by the PCR detection method. The species composition of bifidobacteria in the fecal specimens did not change significantly throughout the study period. These findings suggest that the species composition of bifidobacteria remains stable even when fecal microflora is improved by food management.

Adult↗
PubMed2002

Adhesive property of Bifidobacterium lactis LKM512 and predominant bacteria of intestinal microflora to human intestinal mucin.

The adhesive property to the intestinal mucin of Bifidobacterium lactis LKM512, B. longum, B. breve, B. bifidum, B. adolescentis, B. infantis, Bacteroides vulgatus, Bacteroides distasonis, Eubacterium aerofaciens, Clostridium perfringens, Escherichia coli, and Lactobacillus acidophilus were examined. Adhesive rate of LKM512 to the mucin was significantly (p < 0.05, 0.01, or 0.001) stronger than the other strains from 2 to 100 time. Though the adhesive property of many strains was almost same to the mucin of 20-year-old and 50-year-old generations, in case of 4-month-old was different. Adhesive inhibitory effect of C. perfringens to the mucin by LKM512 was examined. Under the condition that LKM512 was 108/ml and that C. perfringens was 106/ml, adhesion of C. perfringens to the mucin was inhibited at 99.6%, when LKM512 adhered in advance. There was the strong inhibition of adhesion at 74.0%, when C. perfringens adhered to mucin in advance. Thus, LKM512 can inhibit the adhesion of harmful bacteria to the intestinal mucin, the possibility of using as a probiotic strain has to be verified.

Adult↗
PubMed2002

Reclassification of Bacteroides forsythus (Tanner et al. 1986) as Tannerella forsythensis corrig., gen. nov., comb. nov.

The characteristics of the fusiform species Bacteroides forsythus, isolated from human periodontal pockets, were examined. 165 rDNA sequence analysis confirmed that B. forsythus was not a species within the genus Bacteroides sensu stricto. Although B. forsythus was phylogenetically related to Bacteroides distasonis and Bacteroides merdae in the phylogenetic tree, the ratio of anteiso-15:0 to iso-15:0 in whole-cell methanolysates of B. forsythus was different from those of B. distasonis, B. merdae and other Bacteroides species. B. forsythus did not grow on medium containing 20% bile, but members of the Bacteroides fragilis group did. B. forsythus was the only species tested that was trypsin-positive in API ZYM tests. The dehydrogenase enzyme pattern was of no use for the differentiation of B. forsythus and the B. fragilis group. On the basis of these data, a new genus, Tannerella, is proposed for Bacteroides forsythus, with one species, Tannerella forsythensis corrig., gen. nov., comb. nov. The type strain of Tannerella forsythensis is JCM 10827T (= ATCC 43037T).

Animals↗
PubMed2002

Unification of Bifidobacterium infantis and Bifidobacterium suis as Bifidobacterium longum.

The relationships between Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium suis were examined by means of carbohydrate fermentation, DNA-DNA hybridization, ribotyping and random amplified polymorphic DNA-PCR (RAPD-PCR). The levels of DNA-DNA hybridization among the strains of B. infantis, B. longum and B. suis used in this study were 67-81% under optimal conditions (42 degrees C) and 63-85% under stringent conditions (52 degrees C). Although the strains showed varied carbohydrate-fermentation patterns, the three species were divided into three types, namely the infantis type, the longum type and the suis type, by ribotyping and RAPD-PCR. On the basis of these results, strains of B. infantis, B. longum and B. suis were recognized as distinct groups within a single species. It is concluded that B. infantis and B. suis should be unified as B. longum, the latter species being divided into three biotypes, the infantis type, the longum type and the suis type, by molecular methods.

Bifidobacterium↗
PubMed2002

Phylogenetic analysis of cecal microbiota in chicken by the use of 16S rDNA clone libraries.

The chicken cecum contains a great many bacteria, most of which are strict anaerobes. A strictly anaerobe culture-based method was used in the present study, in conjunction with the 16S rDNA clone library, to elucidate bacterial diversity and the phylogenetic relationship of cecal microbiota in the chicken. A comparative 16S rDNA sequence analysis of cultivated strains and retrieved clones from cecal contents was performed. Approximately 90% of the bacterial cells detected by microscopy did not form colonies on a medium 10 in plate-in-bottle. The 19 isolated strains yielded 11 distinct rDNA sequences, 58% of which were classified as low G + C gram-positive bacteria, 26% were related to Bacteroides spp., and 16% were classified as Proteobacteria. Based on the sequence analysis of 164 clones, 24% were identified to belong to 8 known species and 76% were considered to be 65 novel phylotypes. Approximately 94% of cloned sequences were classified into low G + C gram-positive bacteria, 4% were related to Bacteroides spp., and 2% were classified into Proteobacteria. Clostridium subcluster XIVa (38%), Clostridium cluster IV (13%), Lactobacillus spp. (24%), and Bacteroides spp. (4%) were the major groups constituting the cecal microbiota in chicken, in which the Clostridium subcluster XIVa was the most phylogenetically diverse group in chicken cecum. The 16S rDNA sequences of Lactobacillus acidophilus, L. crispatus, L. salivarius, and L. reuteri were the most frequently found in the Lactobacillus group in chicken cecum.

Animals↗
PubMed2002

Comparison of four microbial enzymes in Clostridia and Bacteroides isolated from human feces.

The activities of four microbial enzymes (azoreductase, nitroreductase, beta-glucuronidase, and beta-glucosidase) in major anaerobic members of human fecal microflora were quantified and the influence of the host factors on expression of these microbial enzyme activities was also investigated. Clostridium paraputrificum and C. clostridiiforme showed much higher activities than other fecal anaerobes tested. Nitroreductase activity in C. paraputrificum isolated from fecal specimens of patients with colon cancer was significantly (P < 0.05) higher than that in the clostridia isolated from healthy subjects and the subjects given high beef diets. However, the activities of some microorganisms tested showed marked differences in each strain.

Aerobiosis↗
PubMed2002

Phylogenetic analysis of the human gut microbiota using 16S rDNA clone libraries and strictly anaerobic culture-based methods.

The human gut microbiota from three healthy subjects were compared by the use of a sequence analysis of 16S rDNA libraries and a culture-based method. Direct counts ranged from 1.9 X 10" to 4.0 X 10" cells/g (wet weight), and plate counts totaled 6.6 X 10(10) to 1.2 X 10(11) CFU/g (wet weight). Sixty to seventy percent of the bacteria in the human intestinal tract cannot be cultured with currently available methods. The 16S rDNA libraries from three subjects were generated from total community DNA in the intestinal tract with universal primer sets. Randomly selected clones were partially sequenced. All purified colonies detected from the surface of the agar plate were used for a partial sequencing of 16S rDNA. On the basis of sequence similarities, the clones and colonies were classified into several clusters corresponding to the major phylum of the domain Bacteria. Among a total of 744 clones obtained, approximately 25% of them belonged to 31 known species. About 75% of the remaining clones were novel "phylotypes" (at least 98% similarity of clone sequence). The predominant intestinal microbial community consisted of 130 species or phylotypes according to the sequence data in this study. The 16S rDNA libraries and colonies included the Bacteroides group, Streptococcus group, Bifidobacterium group, and Clostridium rRNA clusters IV, IX, XIVa, and XVIII. Moreover, several previously uncharacterized and uncultured microorganisms were recognized in clone libraries and colonies. Our results also showed marked individual differences in the composition of intestinal microbiota.

Adult↗
PubMed2002

Stimulation of the secretion of pro-inflammatory cytokines by Bifidobacterium strains.

To characterize the ability of bifidobacteria to affect the production of macrophage-derived cytokines, a murine macrophage-like cell line, J774.1, was cultured in the presence of 27 strains of heat-inactivated bifidobacteria. Bifidobacterium adolescentis and B. longum, known as adult-type bifidobacteria, induced significantly more pro-inflammatory cytokine secretion, IL-12 and TNF-alpha, by J774.1 cells, than did the infant-type bifidobacteria, B. bifidum, B. breve, and B. infantis (P<0.01). In contrast, B. adolescentis did not stimulate the production of anti-inflammatory IL-10 from J774.1 cells as the other tested bacteria did. The results suggest that the adult-type bifidobacteria, especially B. adolescentis, may be more potent to amplify but less able to down-regulate the inflammatory response.

Adult↗
PubMed2002

Fecal microbial diversity in a strict vegetarian as determined by molecular analysis and cultivation.

Fecal microbial diversity in a strictly vegetarian woman was determined by the 16S rDNA library method, terminal restriction fragment length polymorphism (T-RFLP) analysis and a culture-based method. The 16S rDNA library was generated from extracted fecal DNA, using bacteria-specific primers. Randomly selected clones were partially sequenced. T-RFLP analysis was performed using amplified 16S rDNA. The lengths of T-RF were analyzed after digestion by HhaI and MspI. The cultivated bacterial isolates were used for partial sequencing of 16S rDNA. Among 183 clones obtained, approximately 29% of the clones belonged to 13 known species. About 71% of the remaining clones were novel "phylotypes" (at least 98% similarity of clone sequence). A total of 55 species or phylotypes were identified among the 16S rDNA library, while the cultivated isolates included 22 species or phylotypes. In addition, many new phylotypes were detected from the 16S rDNA library. The 16S rDNA library and isolates commonly included the Bacteroides group, Bifidobacterium group, and Clostridium rRNA clusters IV, XIVa, XVI and XVIII. T-RFLP analysis revealed the major composition of the vegetarian gut microbiota were Clostridium rRNA subcluster XIVa and Clostridium rRNA cluster XVIII. The dominant feature of this strictly vegetarian gut microbiota was the detection of many Clostridium rRNA subcluster XIVa and C. ramosum (Clostridium rRNA cluster XVIII).

Adult↗