The impact of probiotics on gut microbiota in the eradication of Helicobacter pylori infection: a systematic review.

OBJECTIVE: The effect of probiotics supplementation on the gut microbiota in Helicobacter pylori (H. pylori) eradication therapy is controversial. Therefore, this review aimed to illustrate changes in the gut microbiota after standard eradication therapy with probiotics supplements. MATERIALS AND METHODS: A computerized literature search in PubMed, Cochrane Library, Web of Science, and Embase database was performed up to February 1st, 2022, with English language restriction. The extracted outcomes were analyzed, including gut microbiota, adverse effects, and eradication rate. RESULTS: 13 studies reported data on 777 participants who were finally eligible for this systematic review. All of them are randomized controlled trials investigating the effect of H. pylori eradication with probiotics supplementation therapy on gut microbiota. Probiotics supplementation seems to play a positive role in restoring the gut microbiota during H. pylori eradication therapy. However, the changes in the gut microbiota are still controversial. The included studies had significant heterogeneity in the study population, diagnostic methods of H. pylori infection, and detection techniques of the gut microbiota and probiotics species. CONCLUSIONS: The results provided a basis for the rational selection of probiotics in the H. pylori eradication process. Probiotic supplementation might keep the balance of gut microbiota and reduce the gastrointestinal adverse effects of antibiotics, but whether it could improve the eradication rate or not is a debatable point. Therefore, more research is needed to provide evidence.

[Research progress on the relationship between liver cirrhosis and thyroid hormones].

There exists a complex relationship between liver and thyroid hormones. Liver plays an important role in the activation, inactivation, transportation, and metabolism of thyroid hormones. At the same time, thyroid hormones also affect hepatocytes activity and liver metabolism, such as lipid and bilirubin metabolism. Importantly, thyroid hormone levels often change abnormally in patients with liver cirrhosis. Therefore, studying the change of thyroid hormone levels in patients with liver cirrhosis has a certain clinical value for assessing the severity, prognosis, diagnosis and treatment. This paper reviews the research progress on the relationship between liver cirrhosis and thyroid hormone.

Identification of a hidden outbreak due to the spread of a VIM-3-producing, extensive drug-resistant Pseudomonas aeruginosa (XDRPA) clone at a regional hospital in Taiwan.

A review of the annual prevalence of Pseudomonas aeruginosa at a regional hospital in Taiwan revealed a significant increase in the incidence of extensive drug-resistant P. aeruginosa (XDRPA) from 2∙1% in 2003 to 5∙8% in 2007. The first XDRPA isolate was recovered in 2001 from the emergency ward. The widespread dissemination of XDRPA isolates to more than 10 other wards was discovered the following year. Six pulsotypes of 67 XDRPA isolates from 2006 onwards were identified and 91% were a single strain, suggesting the existence of a hidden outbreak. Prior to the recognition of the outbreak, the majority of cases were not considered to be healthcare-associated infections until molecular evidence was provided. A cohort measure was launched by the infection control practitioners that effectively controlled the outbreak. Patients with XDRPA were mostly referred from neighbouring long-term care facilities, which may have been the reservoir of the XDRPA clone.

A 7-year surveillance for ESBL-producing Escherichia coli and Klebsiella pneumoniae at a university hospital in Taiwan: the increase of CTX-M-15 in the ICU.

To monitor the changing trend of extended-spectrum beta-lactamase (ESBL)-producing bacteria, a 7-year continuous study was launched in 2001 at the largest tertiary hospital in Taiwan. A significant increase over the study period was evident for ESBL-producing isolates of Escherichia coli (4.8-10.0%) and Klebsiella pneumoniae (15.0-23.4%). Molecular investigation conducted in three separate periods revealed the prevalent ESBL types and their genetic relatedness. CTX-M-producing isolates (73.8%) were more prevalent than SHV-type ESBLs (37.0%), the most frequent being CTX-M-14 (34.3%), CTX-M-3 (25.9%), and SHV-12 (25.7%). However, a marked increase of CTX-M-15-producing isolates from 2.1% in 2002 to 29.6% in 2007 was also noted. The increase of ESBL-producing isolates in both species may be mainly due to the horizontal transmission of resistance plasmids, while clonal expansion of some epidemic strains further added to the dispersion of ESBL-producing K. pneumoniae.

Effect of curcumin on the proliferation and apoptosis of hepatic stellate cells

This study was designed to investigate the effect of curcumin (diferuloylmethane) on the proliferation and apoptosis of hepatic stellate cells (HSC). The cell line HSC-T6 (1.25 x 10(5) cells/mL) was incubated with curcumin and HSC proliferation was detected by a methyl thiazolyl tetrazolium colorimetric assay. HSC apoptosis was detected by flow cytometry, transmission electron microscope and agarose gel electrophoresis. HSC proliferation was significantly inhibited in a concentration-dependent manner (10.6 to 63.5 percent) after incubation with 20-100 ìM curcumin, compared with a control group. At 20, 40, and 60 ìM, after 24 h of incubation, curcumin was associated with a significant increase in the number of HSC in the G2/M phase, and a significant decrease in cell numbers in the S phase (P < 0.05). At these concentrations, curcumin was also associated with an increase in the apoptosis index of 15.3 ± 1.9, 26.7 ± 2.8, and 37.6 ± 4.4 percent, respectively, compared to control (1.9 ± 0.6 percent, P < 0.01). At 40 ìM, the curcumin-induced apoptosis index at 12, 24, 36, and 48 h of incubation was 12.0 ± 2.4, 26.7 ± 3.5, 33.8 ± 1.8, and 49.3 ± 1.6 percent, respectively (P < 0.01). In conclusion, curcumin inhibits the in vitro proliferation of HSCs in the G2/M phase of the cell cycle and also induces apoptosis in a concentration- and time-dependent manner. The in vivo effect of curcumin on HSCs requires further investigation.

Effect of curcumin on the proliferation and apoptosis of hepatic stellate cells.

This study was designed to investigate the effect of curcumin (diferuloylmethane) on the proliferation and apoptosis of hepatic stellate cells (HSC). The cell line HSC-T6 (1.25 x 10(5) cells/mL) was incubated with curcumin and HSC proliferation was detected by a methyl thiazolyl tetrazolium colorimetric assay. HSC apoptosis was detected by flow cytometry, transmission electron microscope and agarose gel electrophoresis. HSC proliferation was significantly inhibited in a concentration-dependent manner (10.6 to 63.5%) after incubation with 20-100 microM curcumin, compared with a control group. At 20, 40, and 60 microM, after 24 h of incubation, curcumin was associated with a significant increase in the number of HSC in the G2/M phase, and a significant decrease in cell numbers in the S phase (P < 0.05). At these concentrations, curcumin was also associated with an increase in the apoptosis index of 15.3 +/- 1.9, 26.7 +/- 2.8, and 37.6 +/- 4.4%, respectively, compared to control (1.9 +/- 0.6%, P < 0.01). At 40 microM, the curcumin-induced apoptosis index at 12, 24, 36, and 48 h of incubation was 12.0 +/- 2.4, 26.7 +/- 3.5, 33.8 +/- 1.8, and 49.3 +/- 1.6%, respectively (P < 0.01). In conclusion, curcumin inhibits the in vitro proliferation of HSCs in the G2/M phase of the cell cycle and also induces apoptosis in a concentration- and time-dependent manner. The in vivo effect of curcumin on HSCs requires further investigation.

Dietary methionine requirement of the Chinese egg-laying duck.

1. The dietary methionine requirement of egg-laying ducks was assessed by feeding diets supplemented with graded levels of DL-methionine (0, 4, 8, 12, 16 g/kg dietary protein) for 8 weeks. The basal diet contained 175 g protein and 2.6 g methionine per kg feed (or 14.9 g/kg protein) and an estimated ME of 11.5 MJ/kg. 2. A total of 800 Shaoxin laying ducks (420 d old) were randomly divided into 5 groups of 160 each and fed in 4 separate pens. 3. Dietary supplementation of methionine significantly increased egg production and feed conversion efficiency. 4. Dietary methionine requirement for optimum egg production was estimated to be 25.7 g/kg of dietary protein or 4.5 g/kg of the diet or 380 mg/bird-d. 5. Methionine supplementation increased the methionine level in plasma, and the free glutamic acid and aspartic acid concentrations in plasma were quadratically related to dietary methionine levels. Increasing dietary methionine had little effect on egg quality characteristics.

Bacillus subtilis mutations that alter the pathway of phosphorylation of the anti-anti-sigmaF factor SpoIIAA lead to a Spo- phenotype.

Sigma-F, the first sporulation-specific transcription factor of Bacillus subtilis, is regulated by an anti-sigma factor SpoIIAB, which can also act as a protein kinase that phosphorylates the anti-anti-sigma factor SpoIIAA. The time course of phosphorylation reaction is biphasic, a fact that has been interpreted in terms of a mechanism for sequestering SpoIIAB away from sigmaF and thus allowing activation of sigmaF when needed. Site-directed mutagenesis of SpoIIAA has allowed us to isolate two mutants that cannot activate sigmaF and which are therefore Spo-. The two mutant SpoIIAA proteins, SpoIIAAL61A and SpoIIAAL90A, are phosphorylated with linear kinetics; in addition they are less able to form the stable non-covalent complex that wild-type SpoIIAA makes with SpoIIAB in the presence of ADP. The phosphorylated form of SpoIIAAL90A was hydrolysed by the specific phosphatase SpoIIE at the same rate as wild-type SpoIIAA-P, but the rate of hydrolysis of SpoIIAAL61A-P was much slower. The secondary structure and the global fold of the mutant proteins were unchanged from the wild type. The results are interpreted in terms of a model for the wild type in which SpoIIAB, after phosphorylating SpoIIAA, is released in a form that is tightly bound to ADP and which then makes a ternary complex with an unreacted SpoIIAA. We propose that it is the inability to make this ternary complex that deprives the mutant cells of a means of keeping SpoIIAB from inhibiting sigmaF.

The role of RsmA in the regulation of swarming motility in Serratia marcescens.

Swarming motility is a multicellular phenomenon comprising population migration across surfaces by specially differentiated cells. In Serratia marcescens, a network exists in which the flhDC flagellar regulatory master operon, temperature, nutrient status, and quorum sensing all contribute to the regulation of swarming motility. In this study, the rsmA (repressor of secondary metabolites) gene (hereafter rsmA(Sm)) was cloned from S. marcescens. The presence of multicopy, plasmid-encoded rsmA(Sm) expressed from its native promoter in S. marcescens inhibits swarming. Synthesis of N-acylhomoserine lactones, presumably by the product of smaI (a luxI homolog isolated from S. marcescens), was also inhibited. Knockout of rsmA(Sm) on the S. marcescens chromosome shortens the time before swarming motility begins after inoculation to an agar surface. A single copy of the chromosomal PrsmA(Sm)::luxAB reporter of rsmA(Sm) transcription was constructed. Using this reporter, the roles of the flhDC flagellar regulatory master operon, temperature and autoregulation in the control of rsmA(Sm) expression were determined. Our findings indicate that RsmA(Sm) is a component of the complex regulatory network that controls swarming.

Role of flhDC in the expression of the nuclease gene nucA, cell division and flagellar synthesis in Serratia marcescens.

We investigated in Serratia marcescens the functions of the flhDC operon, which controls motility and cell division in enteric bacteria. Included in our evaluations were investigation of cell division, flagellar synthesis and regulation of the expression of nuclease (encoded by the nucA(Sm) gene, one of the virulence factors). Interruption of the chromosomal flhDC operon in S. marcescens CH-1 resulted in aberrant cell division and loss of nuclease and flagella. Expression of nucA(Sm) and other mutated phenotypes was restored in the flhDC mutant by the induction of overexpression of flhDC in a multicopy plasmid. Multicopied flhDC also induced the formation of differentiated cells (polyploid aseptate cells with oversynthesis of peritrichous flagella) in broth culture using minimal growth medium. Expression of the flhDC operon showed positive autoregulation, and was growth phase dependent (upregulated in early log phase). In addition, flhDC expression was inhibited when the temperature increased from 30 to 37 degrees C, and when osmolarity was increased, but was not influenced by glucose catabolite repression. These results show that FlhD/FlhC is a multifunctional transcriptional activator involved in the process of cell differentiation, swarming and virulence factor expression.

Effect of glucose concentration on swimming motility in enterobacteria.

Since the observation that glucose prevents the synthesis of flagella in Escherichia coli was first reported in 1967, many studies have addressed the underlying mechanism. Currently, it is thought that an increase in glucose concentration decreases the intracellular CRP/cAMP concentration. This leads to an inhibitory effect on the expression of the flhD operon, the master operon for flagella synthesis. In our study on defining factors influencing the cell differentiation of Serratia marcescens, glucose catabolite repression of hag expression and swimming/swarming motility was not observed. Further experiments using a simple swimming motility assay extended this observation to other members of Enterobacteriaceae. Although the underlying mechanism is still uncharacterised, our results suggest that glucose catabolite repression of swimming motility may not be a common phenomenon in Enterobacteriaceae.