Green tea powder and Lactobacillus plantarum affect gut microbiota, lipid metabolism and inflammation in high-fat fed C57BL/6J mice

BACKGROUND: Type 2 diabetes is associated with obesity, ectopic lipid accumulation and low-grade inflammation. A dysfunctional gut microbiota has been suggested to participate in the pathogenesis of the disease. Green tea is rich in polyphenols and has previously been shown to exert beneficial metabolic effects. Lactobacillus plantarum has the ability to metabolize phenolic acids. The health promoting effect of whole green tea powder as a prebiotic compound has not been thoroughly investigated previously. METHODS: C57BL/6J mice were fed a high-fat diet with or without a supplement of 4% green tea powder (GT), and offered drinking water supplemented with Lactobacillus plantarum DSM 15313 (Lp) or the combination of both (Lp + GT) for 22 weeks. Parameters related to obesity, glucose tolerance, lipid metabolism, hepatic steatosis and inflammation were examined. Small intestinal tissue and caecal content were collected for bacterial analysis. RESULTS: Mice in the Lp + GT group had significantly more Lactobacillus and higher diversity of bacteria in the intestine compared to both mice in the control and the GT group. Green tea strongly reduced the body fat content and hepatic triacylglycerol and cholesterol accumulation. The reduction was negatively correlated to the amount of Akkermansia and/or the total amount of bacteria in the small intestine. Markers of inflammation were reduced in the Lp + GT group compared to control. PLS analysis of correlations between the microbiota and the metabolic variables of the individual mice showed that relatively few components of the microbiota had high impact on the correlation model. CONCLUSIONS: Green tea powder in combination with a single strain of Lactobacillus plantarum was able to promote growth of Lactobacillus in the intestine and to attenuate high fat diet-induced inflammation. In addition, a component of the microbiota, Akkermansia, correlated negatively with several metabolic parameters known to be risk factors for the development of type 2 diabetes

Intake of Blueberry Fermented by Lactobacillus plantarum

Prebiotics, probiotics, or synbiotics can be used as means to regulate the microbiota to exert preventative or beneficial effects to the host. However, not much is known about the effect of the gut microbiota on hypertension which is a major risk factor of cardiovascular disease and also a symptom of the metabolic syndrome. The N(G)-nitro-L-arginine methyl ester (L-NAME) induced hypertensive rats were used in order to test the effect of a synbiotic dietary supplement of Lactobacillus plantarum HEAL19 either together with fermented blueberry or with three phenolic compounds synthesized during fermentation. The experimental diets did not lower the blood pressure after 4 weeks. However, the fermented blueberries together with live L. plantarum showed protective effect on liver cells indicated by suppressed increase of serum alanine aminotransferase (ALAT) levels. The diversity of the caecal microbiota was neither affected by L-NAME nor the experimental diets. However, inhibition of the nitric oxide synthesis by L-NAME exerted a selection pressure that led to a shift in the bacterial composition. The mixture of fermented blueberries with the bacterial strain altered the caecal microbiota in different direction compared to L-NAME, while the three phenolic compounds together with the bacteria eliminated the selection pressure from the L-NAME

The Lactobacillus flora in vagina and rectum of fertile and postmenopausal healthy Swedish women

<p>Abstract</p> <p>Background</p> <p><it>Lactobacillus </it>species are the most often found inhabitants of vaginal ecosystem of fertile women. In postmenopausal women with low oestrogen levels, <it>Lactobacillus </it>flora is diminishing or absent. However, no studies have been performed to investigate the correlation between oestrogen levels and the lactobacilli in the gut. The aim of the present study was to investigate the relation in healthy women between vaginal and rectal microbial flora as well as possible variations with hormone levels.</p> <p>Methods</p> <p>Vaginal and rectal smears were taken from 20 healthy fertile women, average 40 years (range 28-49 years), in two different phases of the menstrual cycle, and from 20 postmenopausal women, average 60 years (range 52-85 years). Serum sex hormone levels were analyzed. Bacteria from the smears isolated on Rogosa Agar were grouped by Randomly Amplified Polymorphic DNA and identified by multiplex PCR and partial 16S rRNA gene sequencing.</p> <p>Results</p> <p><it>Lactobacillus crispatus </it>was more often found in the vaginal flora of fertile women than in that of postmenopausal (p = 0.036). Fifteen of 20 fertile women had lactobacilli in their rectal smears compared to 10 postmenopausal women (p = 0.071). There was no correlation between the number of bacteria in vagina and rectum, or between the number of bacteria and hormonal levels. Neither could any association between the presence of rectal lactobacilli and hormonal levels be found.</p> <p>Conclusion</p> <p><it>Lactobacillus crispatus </it>was more prevalent in the vaginal flora of fertile women, whereas the <it>Lactobacillus </it>flora of rectum did not correlate to the vaginal flora nor to hormonal levels.</p

Characterisation of Food Associated Bacteria by DNA based Methods, with Special Reference to Enterobacteriaceae

The presence of genes in food, encoding some virulence factors, was studied by PCR, and species of Enterobacteriaceae, associated with food, were studied by the DNA-based methods of TTGE, ribotyping and sequencing. The flora of fresh and chill-stored pork were analysed by a culture-independent approach, using specific amplification of 16S rRNA genes followed by cloning and sequencing. No evidence for the presence of toxin coding genes related to E. coli was found in meat and fish but a strain of Serratia liquefaciens positive for the Yersinia HPI, was isolated from a sample of beef. Up to now, this is the first Serratia found to be HPI positive but the significance, from a food hygiene point of view, is not clear and S. liquefaciens is only occasionally isolated from clinical specimens. For the primary purpose of evaluating the TTGE method for identification of Enterobacteriaceae associated with food, strains isolated from meat, fish and milk and human isolates of Klebsiella, a genus that is frequently found in food, were included in the study. TTGE proved to be a tool for differentiating E. coli, E. vulneris, E. cloacae, E. amylovora, H. alvei, K. terrigena, P. agglomerans, R. aquatilis, and distinguished between the clinically important strains of K. pneumoniae and K. oxytoca. In addition, it was possible to identify R. aquatilis genomospecies (GS) 1 and 2 and presumably one additional GS group of this species using TTGE. The closely related species of K. planticola, K. ornithinolytica and E. aerogens were not separated by TTGE. Furthermore, the C. freundii and Y. ruckeri type strains could not be distinguished from each other and S. liquefaciens and S. proteamaculans could not be identified due to diffuse or lack of band on the gel. Ribotyping was useful to subdivide Rahnella aquatilis into genomic subtypes and for confirmation of the TTGE grouping. The strains of H. alvei and S. liquefaciens were genomically defined by ribotyping. Sequencing of 16S rRNA genes was useful for the verification of the identity of Klebsiella isolates and the different Rahnella genomospecies. In addition a protocol was developed for rapid identification of Klebsiella spp. By picking a colony from an agar plate, preparing the DNA for PCR and running TTGE over night, identification was possible within 24 hours. A culture-independent analysis of the flora of fresh and chill-stored pork gave an overall picture, of the bacterial composition, which was in agreement with cultivation-dependent methods previously used. The initial flora turned out to be diverse in terms of the numbers of genera present, and a change occurred during refrigerated storage into a gram-negative psychrotrophic flora, dominated by Pseudomonas. The method used here also indicated the possibility of detecting bacterial species such as Eperythrozoon, that do not grow on ordinary media

DNA based classification of food associated Enterobacteriaceae previously identified by biolog GN microplates

Enterobacteriaceae are frequently isolated from food products and it is essential to have methods for correct identification for both food hygiene and epidemiology reasons. Phenotypic methods are not always sufficient and have to be supplemented by DNA based methods. In the present study, 70 strains of Enterobacteriaceae derived from milk, fish and meat that had previously been identified by Biolog GN Microplates were genomically classified together with 15 representative type strains of species of Enterobacteriaceae. The field strains were dominated by Hafnia alvei, Serratia liquefaciens and Rahnella aquatilis. All strains were subjected to temporal temperature gel electrophoresis (TTGE) analysis using amplicons encompassing the V3, V4 and V9 variable regions of the 16S rRNA gene. Selected strains were analysed by ribotyping and partial 16S rDNA sequencing. The type strains were differentiated into 10 different TTGE groups. Two of the groups contained two type strains. Enterobacter aerogenes and Klebsiella planticola were not distinguished due to their identical sequences and Yersinia ruckeri and Citrobacter freundii showed the same migration pattern. The 70 food strains could be differentiated into 14 TTGE groups where 33 strains (47.1%) could be assigned to TTGE groups including type or reference strains. Rabnella strains were dispersed into three TTGE groups of which one group corresponded to Rahnella genomospecies 1 and one to genomospecies 3. The grouping of Rabnella strains was supported by ribotyping and phylogenetic analysis. TTGE can be a useful additional tool for identification on the species level of food related Enterobacteriaceae

The Yersinia HPI is present in Serratia liquefaciens isolated from meat.

Aims: The aim of the study was to screen the Enterobacteriaceae flora of meat for the presence of bacteria harbouring the Yersinia high-pathogenicity island (HPI). Methods and Results: Bacteria from 29 meat and 29 liver samples were isolated on violetred bile glucose agar. A total of 197 isolates were screened for the presence of the irp2 gene, encoded within the HPI, by PCR. One isolate that was positive for irp2 gene was also positive for the fyuA, irp1, ybtP/ybtQ, ybtX/ybtS and int/asn tRNA genes by PCR. The presence of fyuA, irp1 and irp2 genes was confirmed by Southern hybridization. Conclusions: The isolate was identified as Serratia liquefaciens by sequencing of the 16S rRNA gene and by ribotyping. Significance and Impact of the Study: This is the first report of a Serratia harbouring the Yersinia HPI. Serratia is a frequently occurring Enterobacteriaceae genus in chill-stored meat

The bacterial flora of fresh and chill-stored pork: analysis by cloning and sequencing of 16S rRNA genes.

The composition of the initial bacterial flora of pork and the development of the flora after storage at +4 °C for 4 days were analysed by amplification, cloning and sequencing of 16S rDNA. A total of 122 clones were obtained, with lengths of ≥400 nucleotides and ≥95% similarity to database sequences. Nineteen clones were similar to sequences in database not assigned to any genera. Fourteen different genera were represented in clones from fresh meat, with 36.5% of the clones most resembling Acinetobacter and 17.3% resembling Staphylococcus and Macrococcus. After storage, the clones were composed of six different genera, with 44.3% resembling Pseudomonas, 17.1% resembling Aeromonas and only 14.3% resembling Acinetobacter. This study shows that the overall pattern of the initial and chill-stored pork flora, as shown by a molecular approach, was in agreement with results obtained in previous studies using traditional cultivation methods