Yakult Honsha European Research Center for Microbiology

Gent, Belgium

Yakult Honsha European Research Center for Microbiology

Gent, Belgium
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Kurakawa T.,Yakult Central Institute for Microbiological Research | Kubota H.,Yakult Central Institute for Microbiological Research | Kubota H.,Yakult Honsha European Research Center for Microbiology | Tsuji H.,Yakult Central Institute for Microbiological Research | And 6 more authors.
Journal of Microbiological Methods | Year: 2013

A primer set specific for Escherichia coli/Shigella 16S rRNA was developed and used for RT-qPCR analysis of fecal samples from 35 healthy adult volunteers in combination with the previously reported primer set specific for Enterobacteriaceae. Enterobacteriaceae and E. coli were present in the 29 out of 35 volunteers tested as intestinal commensals at the average population levels of 107.1±0.9 and 106.8±0.7cellsg-1 of stools (mean±standard deviation), respectively. Among the 7 volunteers, the significant deviation between the count of Enterobacteriaceae and that of E. coli was observed, suggesting non-E. coli/Shigella species were predominant in their Enterobacteriaceae populations. The clone library analysis revealed that the non-E. coli/Shigella populations included Citrobacter freundii, Citrobacter koseri, Enterobacter cloacae, Klebsiella oxytoca, Klebsiella pneumoniae/variicola and Morganella morganii. These data suggested that the RT-qPCR method with the primer sets specific to both Enterobacteriaceae and E. coli/Shigella enabled the accurate enumeration of intestinal E. coli populations and the other Enterobacteriaceae species populations. © 2012 Elsevier B.V.


Matsuda K.,Yakult Central Institute for Microbiological Research | Tsuji H.,Yakult Central Institute for Microbiological Research | Asahara T.,Yakult Central Institute for Microbiological Research | Takahashi T.,Yakult Central Institute for Microbiological Research | And 5 more authors.
Applied and Environmental Microbiology | Year: 2012

We established a sensitive and accurate quantification system for Clostridium difficile in human intestines, based on rRNA-targeted reverse transcription-quantitative PCR (RT-qPCR). We newly developed a species-specific primer set for C. difficile targeting 23S rRNA gene sequences. Both the vegetative cells and the spores of C. difficile in human feces were quantified by RT-qPCR,with a lower detection limit of 102.4 cells/g of feces. In an analysis of the feces of residents (n=83; age, 85±8 years) and staff(n=19; age, 36±10 years) at a care facility for the elderly, C. difficile was detected by RT-qPCR in 43% of the residents (average count, log10 4.0±2.0 cells/gof feces) and 16% of the staff (average count, log10 2.2±0.1 cells/g of feces); these rates were far higher than those detected by qPCR (residents, 19%; staff, 0%) or selectivecultivation (residents, 18%; staff, 5%). Another analysis of healthy adults (n=63; age, 41±11 years) also revealedthe significant carriage rate of C. difficile in the intestines (detection rate, 13%; average count, log10 4.9±1.2 cells/g of feces). From these results, it was suggested that rRNA-targeted RT-qPCR should be an effective tool for analyzing population levels of C. difficile in the human intestine. © 2012, American Society for Microbiology.


Sakai T.,Yakult Honsha European Research Center for Microbiology | Makino H.,Yakult Honsha European Research Center for Microbiology | Ishikawa E.,Yakult Honsha European Research Center for Microbiology | Oishi K.,Yakult Honsha European Research Center for Microbiology | Kushiro A.,Yakult Honsha European Research Center for Microbiology
International Journal of Food Sciences and Nutrition | Year: 2011

The objective of the present study was to investigate the efficacy of fermented milk containing Lactobacillus casei strain Shirota (LcS) in a healthy population. Healthy subjects with Bristol Stool Form Scale (BS) score < 3.0 were randomized to fermented milk treatment for 3 weeks or non-intervention control. The primary endpoint was the proportion of subjects that produced hard or lumpy stools (HLS) ≥ 25% of bowel movements (H-HLS). Secondary endpoints included changes in BS score, constipation-related symptom scores and stool parameters. Efficacy was analyzed in 39 subjects. After 3 weeks of treatment the proportion of H-HLS subjects had significantly decreased from 73.7% to 36.8%, whereas in the control group the proportion had increased from 75.0% to 85.0% during the same period (P = 0.002). The BS score was significantly improved after the treatment compared with the control (P < 0.001). In conclusion, daily consumption of fermented milk containing LcS reduced the incidence of HLS. © 2011 Informa UK, Ltd.


Fujimoto J.,Yakult Central Institute for Microbiological Research | Tanigawa K.,Yakult Central Institute for Microbiological Research | Kudo Y.,Yakult Central Institute for Microbiological Research | Makino H.,Yakult Honsha European Research Center for Microbiology | Watanabe K.,Yakult Central Institute for Microbiological Research
Journal of Applied Microbiology | Year: 2011

Aims: To develop a quick and accurate PCR-based method to evaluate viable Bifidobacterium breve strain Yakult (BbrY) in human faeces.Methods and Results: The number of BbrY in faeces was detected by using strain-specific quantitative real-time PCR (qPCR) derived from a randomly amplified polymorphic DNA analysis. And using propidium monoazide (PMA) treatment, which combined a DNA-intercalating dye for covalently linking DNA in dead cells and photoactivation, only viable BbrY in the faeces highly and significantly correlated with the number of viable BbrY added to faecal samples within the range of 105-109 cells per g of faeces was enumerated. After 11 healthy subjects ingested 10.7 log CFU of BbrY daily for 10 days, 6.9 (±1.5) log CFU g-1 [mean (±SD)] of BbrY was detected in faeces by using strain-specific transgalactosylated oligosaccharide-carbenicillin (T-CBPC) selective agar medium. Viable BbrY detected by qPCR with PMA treatment was 7.5 (±1.0) log cells per g and the total number (viable and dead) of BbrY detected by qPCR without PMA treatment was 8.1 (±0.8) log cells per g.Conclusions: Strain-specific qPCR with PMA treatment evaluated viable BbrY in faeces quickly and accurately.Significance and Impact of the Study: Combination of strain-specific qPCR and PMA treatment is useful for evaluating viable probiotics and its availability in humans. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.


Akiyama T.,Yakult Honsha European Research Center for Microbiology | Kimura K.,Yakult Central Institute | Hatano H.,Yakult Central Institute
Bioscience, Biotechnology and Biochemistry | Year: 2015

Galactooligosaccharides (GOS) possess prebiotic properties that speci fically increase the number of bifidobacteria in the human intestine, thus giving health benefits to the host. Although the bifidogenic effect of GOS has been demonstrated in numerous studies, the utilization of GOS by specifi c bifidobacteria remains unclear. The goal of our study was to elucidate GOS consumption by specific bifidobacteria and gain insights into the mechanism. First, we examined GOS consumption by 14 bifidobacterial strains belonging to seven different species by comparing growth rate, carbohydrate consumption, and acid production. We then performed a transcription analysis in the case of one strong GOS consumer, Bifidobacterium adolescentis YIT 4011T, to predict the operon contributing to GOS use. The study indicated the contribution of an operon consisted of LacS symporter and β-galactosidase to bifidobacterial GOS consumption. © 2014 Japan Society for Bioscience, Biotechnology, and Agrochemistry.


Makino H.,Yakult Central Institute for Microbiological Research | Makino H.,Yakult Honsha European Research Center for Microbiology | Fujimoto J.,Yakult Central Institute for Microbiological Research | Watanabe K.,Yakult Central Institute for Microbiological Research
International Journal of Food Microbiology | Year: 2010

Yeast contamination is a problem in the food industry as a cause of spoilage. Moreover, various species of yeasts are known to be capable of causing opportunistic infections in humans. We have developed a real-time quantitative PCR (qPCR) assay to directly detect and quantify nine emerging opportunistic yeast species (Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Clavispora lusitaniae, Filobasidiella neoformans, Issatchenkia orientalis, Trichosporon asahii, and Trichosporon jirovecii) in dairy product samples. We designed six primer pairs, conserved sequences of the variable D1/D2 domains of the 26S rRNA gene, to detect the yeasts and demonstrated their specificity. The qPCR assay could accurately quantify emerging opportunistic yeasts in an artificially contaminated dairy product. qPCR with the primer pairs we designed, was very sensitive and will allow producers to enumerate contaminating yeasts and identify whether they are opportunistic pathogens, in only 4 to 5. h. This assay can easily be extended to other food items and to a variety of food-monitoring initiatives. © 2010 Elsevier B.V.


PubMed | University of Lille Nord de France, University of Bologna, National Taiwan University of Science and Technology, Yakult Central Institute and Yakult Honsha European Research Center for Microbiology
Type: Journal Article | Journal: Systematic and applied microbiology | Year: 2015

The species Bifidobacterium longum is currently divided into three subspecies, B. longum subsp. longum, B. longum subsp. infantis and B. longum subsp. suis. This classification was based on an assessment of accumulated information on the species phenotypic and genotypic features. The three subspecies of B. longum were investigated using genotypic identification [amplified-fragment length polymorphism (AFLP), multilocus sequence analysis (MLSA) and multilocus sequence typing (MLST)]. By using the AFLP and the MLSA methods, we allocated 25 strains of B. longum into three major clusters corresponding to the three subspecies; the cluster comprising the strains of B. longum subsp. suis was further divided into two subclusters differentiable by the ability to produce urease. By using the MLST method, the 25 strains of B. longum were divided into eight groups: four major groups corresponding to the results obtained by AFLP and MLSA, plus four minor disparate groups. The results of AFLP, MLSA and MLST analyses were consistent and revealed a novel subspeciation of B. longum, which comprised three known subspecies and a novel subspecies of urease-negative B. longum, for which the name B. longum subsp. suillum subsp. nov. is proposed, with type strain Su 851(T)=DSM 28597(T)=JCM 19995(T).


PubMed | Yakult Central Institute and Yakult Honsha European Research Center for Microbiology
Type: Journal Article | Journal: Beneficial microbes | Year: 2015

We investigated the effects of Streptococcus thermophilus YIT 2001, a strain of lactic acid bacteria, on the susceptibility of low-density lipoprotein (LDL) to oxidation and the formation of aortic fatty lesions in hyperlipidemic hamsters. S. thermophilus YIT 2001 had the highest in vitro antioxidative activity against LDL oxidation among the 79 strains of lactic acid bacteria and bifidobacteria tested, which was about twice that of S. thermophilus YIT 2084. The lag time of LDL oxidation in the YIT 2001 feeding group was significantly longer than in controls, but was unchanged in the YIT 2084 group. After the feeding of YIT 2001, lag times were prolonged and areas of aortic fatty lesions were dose-dependently attenuated, although there were no effects on plasma lipid levels. These results suggest that YIT 2001 has the potential to prevent the formation of aortic fatty lesions by inhibiting LDL oxidation.


PubMed | Belgium Yakult Central Institute, Clinical Pharmacology Unit Antwerpen and Yakult Honsha European Research Center for Microbiology
Type: Journal Article | Journal: Beneficial microbes | Year: 2015

Constipation and haemorrhoids are common complaints after childbirth. The objective of this pilot study was to evaluate impact of fermented milk containing Lactobacillus casei strain Shirota (LcS) on stool consistency and frequency, constipation-related symptoms and quality of life, and incidence of haemorrhoids in women during puerperium. Forty women who had natural childbirth were randomised to group consuming either one bottle/day of fermented milk containing at least 6.5109 cfu of LcS, or placebo, for 6 weeks after childbirth. Subjects filled in a diary on their bowel habits including number of bowel movement, stool consistency and incidence of haemorrhoids, and answered questionnaires on constipation-related symptoms (PAC-SYM) and quality of life (PAC-QOL) during the study period. The probiotic group showed the better scores on overall PAC-SYM (P=0.013), PAC-SYM subscales of abdominal symptoms (P=0.043) and rectal symptoms (P=0.031), and PAC-QOL satisfaction subscale (P=0.037) in comparison with the placebo group. In the probiotic group, two to four subjects experienced haemorrhoids during the first 3 weeks of treatment. The number decreased in week 4 and no one had haemorrhoids on most days in week 5-6. In the placebo group, on average four subjects had haemorrhoids from the beginning, and no obvious change was observed until week 6. No statistically significant effect was observed on stool consistency and frequency. The study products did not cause any adverse event in the subjects. Results of this study indicate that continuous consumption of fermented milk containing LcS might alleviate constipation-related symptoms, provide satisfactory bowel habit and result in earlier recovery from haemorrhoids in women during puerperium. Nonetheless, there are several limitations in interpretation of the results attributed to the study design, including lack of baseline data. Further study is required in order to confirm the efficacy.


Makino H.,Yakult Central Institute for Microbiological Research | Kushiro A.,Yakult Central Institute for Microbiological Research | Ishikawa E.,Yakult Central Institute for Microbiological Research | Kubota H.,Yakult Central Institute for Microbiological Research | And 10 more authors.
PLoS ONE | Year: 2013

Objectives: Bifidobacterium species are one of the major components of the infant's intestine microbiota. Colonization with bifidobacteria in early infancy is suggested to be important for health in later life. However, information remains limited regarding the source of these microbes. Here, we investigated whether specific strains of bifidobacteria in the maternal intestinal flora are transmitted to their infant's intestine. Materials and Methods: Fecal samples were collected from healthy 17 mother and infant pairs (Vaginal delivery: 12; Cesarean section delivery: 5). Mother's feces were collected twice before delivery. Infant's feces were collected at 0 (meconium), 3, 7, 30, 90 days after birth. Bifidobacteria isolated from feces were genotyped by multilocus sequencing typing, and the transitions of bifidobacteria counts in infant's feces were analyzed by quantitative real-time PCR. Results: Stains belonging to Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium catenulatum, Bifidobacterium longum subsp. longum, and Bifidobacterium pseudocatenulatum, were identified to be monophyletic between mother's and infant's intestine. Eleven out of 12 vaginal delivered infants carried at least one monophyletic strain. The bifidobacterial counts of the species to which the monophyletic strains belong, increased predominantly in the infant's intestine within 3 days after birth. Among infants delivered by C-section, monophyletic strains were not observed. Moreover, the bifidobacterial counts were significantly lower than the vaginal delivered infants until 7 days of age. Conclusions: Among infants born vaginally, several Bifidobacterium strains transmit from the mother and colonize the infant's intestine shortly after birth. Our data suggest that the mother's intestine is an important source for the vaginal delivered infant's intestinal microbiota. © 2013 Makino et al.

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