Prospects for clinical applications of butyrate-producing bacteria.

As the major source of energy for colonic mucosal cells and as an important regulator of gene expression, inflammation, differentiation, and apoptosis in host cells, microbiota-derived butyrate can enhance the intestinal mucosal immune barrier, modulate systemic immune response, and prevent infections. Maintaining a certain level of butyrate production in the gut can help balance intestinal microbiota, regulate host immune response, and promote the development and maintenance of the intestinal mucosal barrier. Butyrate-producing bacteria act as probiotics and play important roles in a variety of normal biological functions. Bacteriotherapeutic supplementation by using fecal microbiota transplantation to restore butyrate-producing commensal bacteria in the gut has been very successful in the treatment of recurrent and refractory Clostridium difficile (C. difficile) infection or C. difficile-negative nosocomial diarrhea. Administration of probiotics that include butyrate-producing bacteria may have a role in the treatment of inflammatory bowel diseases and in the prevention of necrotizing enterocolitis and late-onset sepsis in premature infants. Furthermore, modulating gut microbiota with dietary approaches may improve intestinal dysbiosis commonly seen in patients with obesity-associated metabolic disorders. Supplementation with a butyrate-producing bacterial stain might be used to increase energy expenditure, improve insulin sensitivity, and to help control obesity and metabolic syndrome.

Risk factors associated with intestinal necrosis in children with failed non-surgical reduction for intussusception.

BACKGROUND: Intestinal necrosis is the most serious complication of intussusception. The risk factors associated with intestinal necrosis in pediatric patients with intussusception have not been well characterized. OBJECTIVE: This study aimed to investigate the risk factors associated with intestinal necrosis in pediatric patients with failed non-surgical reduction for intussusception. METHODS: Hospitalized patients who failed the air-enema reduction for intussusception in the outpatient department and subsequently underwent surgery were retrospectively reviewed. All cases were categorized into two groups: intestinal necrosis group and non-intestinal necrosis group based on the surgical findings. Demographic and clinical features including the findings from the surgery were recorded and analyzed. Factors associated with intestinal necrosis were analyzed using univariate and multivariate unconditional logistic regression analyses. RESULTS: A total of 728 cases were included. Among them, 171 had intestinal necrosis at the time of surgery. The group with intestinal necrosis had a longer duration of symptom or length of illness (P = 0.000), and younger (P = 0.000) than the non-intestinal necrosis group. Complex/compound type of intussusceptions is more likely to have intestinal necrosis. Multivariate analysis showed that the presence of grossly bloody stool (OR = 2.12; 95% CI 1.19-3.76, P = 0.010) and duration of symptom (OR = 1.07; 95% CI 1.06-1.08, P = 0.000) were independent risk factors for intestinal necrosis in patients hospitalized for surgical reduction for intussusceptions. CONCLUSION: At time of admission, the presence of bloody stools and duration of symptom are the important risk factors for developing intestinal necrosis for those patients who failed non-surgical reduction. The length of illness has the highest sensitivity and specificity to correlate with intestinal necrosis. This finding may suggest that we should take the intussusception cases that have the longer duration of symptom directly to operation room for reduction.

[Determination of the carboxyl content of oxidized starch by fourier transform infrared (FTIR) spectroscopy].

In the present study, the carboxyl content of oxidized starch was determined by FTIR spectroscopy. Standard curve was drawn in which the ordinate was carboxyl content determined by national standard method with the ratio of carbonyl absorbance to the key of C-H absorbance in FTIR spectroscopy as the abscissa. The ratio of absorbance of unknown oxidized starch tested by FTIR spectroscopy was obtained, The carboxyl content was calculated by standard curve, and then compared with the carboxyl content determined by national standard method, and the deviation is between 2% and 4%. In order to improve the accuracy of the experiment, standard sample was selected to draw standard curve to better ensure that the carboxyl content of the unknown oxidized starch is in the range of standard curve calculation limit, and deviates from the limit of standard curve. Compared with the carboxyl content determined by national standard method, testing with FTIR spectroscopy is simple, easy to operate, and of high efficiency and better accuracy. So, it is significant to forecast the carboxyl content of oxidized starch by FTIR spectroscopy.

Inhibition of p38 mitogen-activated protein kinase attenuates butyrate-induced intestinal barrier impairment in a Caco-2 cell monolayer model.

OBJECTIVES: Butyrate is well known to induce apoptosis in differentiating intestinal epithelial cells. The present study was designed to examine the role of p38 mitogen-activated protein kinase (MAPK) in butyrate-induced intestinal barrier impairment. METHODS: The intestinal barrier was determined by measuring the transepithelial electrical resistance (TER) in a Caco-2 cell monolayer model. The permeability was determined by measuring transepithelial passage of fluorescein isothiocyanate-conjugated inulin (inulin-FITC). The morphology of the monolayers was examined with scanning electron microscopy. The apoptosis status was determined by annexin V-FITC labeling and flow cytometry. The activity of p38 MAPK was determined by the phosphorylation status of p38 with Western blotting. RESULTS: Butyrate at 5 mM increases the apoptosis rate of Caco-2 cells and induces impairment of intestinal barrier functions as determined by decreased TER and increased inulin-FITC permeability. Butyrate treatment activates p38 MAPK in a concentration- and time-dependent manner. SB203580, a specific p38 inhibitor, inhibits butyrate-induced Caco-2 cell apoptosis. Treatment of SB203580 significantly attenuates the butyrate-induced impairment of barrier functions in the Caco-2 cell monolayer model. CONCLUSIONS: p38 MAPK can be activated by butyrate and is involved in the butyrate-induced apoptosis and impairment of intestinal barrier function. Inhibition of p38 MAPK can significantly attenuate butyrate-induced intestinal barrier dysfunction.

Bacterial colonization and intestinal mucosal barrier development.

The intestinal tract is colonized soon after birth with a variety of ingested environmental and maternal microflora. This process is influenced by many factors including mode of delivery, diet, environment, and the use of antibiotics. Normal intestinal microflora provides protection against infection, ensures tolerance to foods, and contributes to nutrient digestion and energy harvest. In addition, enteral feeding and colonization with the normal commensal flora are necessary for the maintenance of intestinal barrier function and play a vital role in the regulation of intestinal barrier function. Intestinal commensal microorganisms also provide signals that foster normal immune system development and influence the ensuing immune responses. There is increasingly recognition that alterations of the microbial gut flora and associated changes in intestinal barrier function may be related to certain diseases of the gastrointestinal tract. This review summarizes recent advances in understanding the complex ecosystem of intestinal microbiota and its role in regulating intestinal barrier function and a few common pediatric diseases. Disruption in the establishment of a stable normal gut microflora may contribute to the pathogenesis of diseases including inflammatory bowel disease, nosocomial infection, and neonatal necrotizing enterocolitis.

[Separation of bile acids by capillary zone electrophoresis].

AIM: To develop a method for separating the major bile acids by capillary zone electrophoresis (CZE). METHODS: The effect of different separations, such as the compose, pH and the concentration of buffer, on the electro-osmotic flow (EOF), the migration time and resolution of 8 bile acids in this system were studied. The general trends in migration time could be correlated to the pH and concentration of the buffer. The effect of organic reagent on EOF and migration time were also investigated. By addition of methanol, the EOF went smaller than before, and better resolution was achieved. The experimental results showed that optimum separation was achieved under the following condition: buffer composition of 126 mmol.L-1 disodium tetraborate, 43 mmol.L-1 disodium hydrogenphosphate, 18% methanol; temperature 30 degrees C; voltage 30 kV; total length of capillary 570 mm and 500 mm from injection end; ultraviolet detection at 200 nm; pressure injection 5 kPa for 8 s. RESULTS: Eight kinds of bile acid had been separated by CZE with only one injection. The method was used to analyse the contents of bile acids from different kinds of bear biles, the recovery was 89%-107%. CONCLUSION: This method is simple and rapid, and can be used to determine the content of bile acids in bear biles. The calibration curve showed good linearity for eight bile acids in the concentration range of 4-60 mg.mL-1 (gamma > 0.9954). The total time for seperation and determination was within 25 min.