Gut Microbiota Diversity and Overweight/Obesity in Infancy: Results from a Nested Case-control Study.

OBJECTIVE: Childhood obesity is a major health concern worldwide. Previous studies have explored the relationship between obesity and gut microbiota. However, the results from such studies remain contradictory. METHODS: In the present nested case-control study, based on a twin birth cohort study, the relationship between gut microbiota diversity and overweight/obesity in 1- and 6-month-old infants was explored. Twins were enrolled when one child had normal weight and the other child was overweight/obese at six months old. For both infants, stool samples were collected at 1 and 6 months of age. Finally, 12 twins were enrolled in the study. The gut microbiota was identified by 16S rRNA gene sequencing in the V3-V4 area. Six of the twins were monozygotic. RESULTS: The results revealed that the microbiota communities of monozygotic twins were similar to those of dizygotic twins. The relative abundance (RA) of microbiota of 1-month-old twins was significantly higher than that of 6-month-old twins. However, the microbiota diversity of 1-month-old twins was significantly lower than that of 6-month-old twins. In addition, 6-month-old twins had significantly higher RA levels of Bifidobacterium and Lachnospiracea incertae sedis than 1-month-old twins. The 6-month-old group had significantly lower RA levels of Veillonella, Klebsiella, Akkermansia, Streptococcus, or Staphylococcus than the 1-month-old group. At six months, the RA level of Clostridium sensu stricto was higher in the overweight/obesity group than the normal-weight group. CONCLUSION: These findings imply that changes in gut microbiota diversity during infancy may contribute to the development of obesity in early infancy.

[Effect of Tween-80 on the permeability of rhodamine 123, a P-gp substrate across rat intestinal membranes in vitro].

OBJECTIVE: To investigate the effect of Tween-80 in modulating rhodamine123 (R123) permeability across the intestinal membranes. METHODS: The permeability of R123 or fluorescein sodium (CF) across isolated rat intestinal membranes at the concentration of 5 microg/ml was evaluated using an in vitro diffusion chamber system, in the presence or absence of Tween-80 at different low concentrations. The concentration of R123 or CF in the receptor chamber was determined using fluorospectrophotometry. RESULTS: The intestinal membrane permeability of R123 gradually decreased from the jejunum to the ileum and then to the colon. The serosal-to-mucosal transport of R123 was much greater than its mucosal-to-serosal transport. In the presence of low concentrations of Tween-80, the absorptive transport of R123 was significantly increased while its secretory transport decreased depending on the concentration of Tween-80. However, Tween-80 at the experimental concentrations was found to obviously affect the CF transport across the intestinal membranes. CONCLUSION: Low concentrations of Tween-80 may promote the absorption of P-gp-mediated drugs and therefore improve the oral bioavailability of these drugs.

An Immunosensing System Using Stilbene Glycoside as a Fluorogenic Substrate for an Enzymatic Reaction Model.

A natural product, stilbene glycoside (2,3,5,4'-tetrahydroxydiphenylethylene-2-O-glucoside, TBG), has been evaluated for the first time as a potential substrate for horseradish peroxidase (HRP)-catalyzed fluorogenic reactions. The properties of TBG as a fluorogenic substrate for HRP and its application in a fluorometric enzyme-linked immunosensing system were compared with commercially available substrates such as p-hydroxyphenylpropionic acid (pHPPA), chavicol and Amplex red using Brucella melitensis antibody (BrAb) as a model analyte. The immunosensing body based on HRP-BrAb was constructed by dispersing graphite, BrAg and paraffin wax at room temperature. In a competitive immunoassay procedure, the BrAb competed with HRP-BrAb to react with the immobilized BrAg. In the enzymatic reaction, the binding HRP-BrAb on the sensing body surface can catalyze the polymerization reaction of TBG by H2O2 forming fluorescent dimers and causing an increase in fluorescence intensity. TBG showed comparable ability for HRP detection and its enzyme-linked immunosensing reaction system, in a linear detection ranging of 3.5´10-8~7.6´10-6g/L and with a detection limit of 1.7´10-9 g/L. The immobilized biocomposite surface could be regenerated with excellent reproducibility (RSD=3.8%) by simply polishing with an alumina paper. The proposed immunosensing system has been used to determine the BrAb in rabbit serum samples with satisfactory results.

[Qualitative fingerprint and quantitative determination of caffeic acid in compound dandelion enema].

OBJECTIVE: To establish a qualitative and quantitative reversed-phase high-performance liquid chromatography (RP-HPLC) with fingerprinting technique for quality control of compound dandelion enema. METHODS: HPLC was utilized for quality assessment of 10 batches of samples. RP-HPLC analysis was performed on a Hypersil BDS C18 column (4.6 mm x 250 mm, 5 microm) with the mixture of acetonitrile (A) and potassium phosphate solution (B) (pH3.2) as the mobile phase in gradient mode. The concentrations of solvent A were 10%, 80% and 80% at 0, 38 and 40 min, respectively. The column temperature was set at 35 degrees C, the flow rate at 0.7 ml/min and the detection wavelength at 254 nm. RESULTS: HPLC fingerprinting was established from the 10 batches, and the data showed 23 characteristic peaks in the compound dandelion enema for use as index peaks for qualitative identification. Comparison of the retention time and the on-line UV spectra of the samples with the chemical standards identified peaks 3, 4 and 8 as protocatechualdehyde, caffeic acid and ferulic acid, respectively. The contents of caffeic acid in the compound dandelion enema ranged between 63.7 and 136.8 microg/ml. CONCLUSION: High specific chromatographic fingerprinting and quantitative measurement of caffeic acid allows rigorous quality control of compound dandelion enema.

[High-performance liquid chromatography combined with mass spectrum analysis for chromatographic fingerprinting of compound dandelion enema].

OBJECTIVE: To identify the active components of compound dandelion enema, a preparation from 7 traditional Chinese herbal drugs for treatment of gynecological diseases. METHODS: Three-dimensional high-performance liquid chromatography (3D-HPLC) was employed to separate the ethyl acetate extract of compound dandelion Enema, and HPLC combined with mass spectrum (MS) analysis used for chromatographic fingerprinting. RESULT: By comparing the ionic fragments of MS and retention time of each peak, the main active components in compound dandelion enema were determined, including caffeic acid, ferulic acid and protocatechualdehyde. CONCLUSION: HPLC coupled with mass spectroscopy can be used for qualitative analysis of compound dandelion enema.

[High-performance capillary electrophoresis for determining caffeic acid content in Fujie enema and Taraxacum mongolicum Hand.-Mazz].

OBJECTIVE: To determine caffeic acid content in Fujie enema and the crude traditional Chinese herbal drug Taraxacum mongolicum Hand.-Mazz. for controlling the quality of the enema at the levels of both the crude drugs and the final product. METHODS: Caffeic acid content in both the enema and the crude drug was determined at 313 nm Using high-performance capillary electrophoresis (HPCE), under the optimized conditions achieved with a fused-silica capillary tube (75 micromx0 cm) and 20 mmol/L borate running buffer (pH=9.18) at a constant voltage of 12 kV and a sampling time of 5 s at 25 degrees Celsius. RESULTS: The calibration curve displayed good linear relationship within caffeic acid concentration range of 10 to 100 microg/ml (r=0.999 2). The regression equation was Y=1002.45X-327.87, and the average recovery was more than 95%. CONCLUSION: HPCE is simple, rapid and sensitive in separation and determination of caffeic acid in Fujie enema and the crude drug of Taraxacum mongolicum Hand.-Mazz.