Effects of empagliflozin on liver fat in patients with metabolic dysfunction-associated steatotic liver disease without diabetes mellitus: A randomized, double-blind, placebo-controlled trial.

BACKGROUND AND AIMS: We investigated whether empagliflozin reduces hepatic steatosis in patients with metabolic dysfunction-associated steatotic liver disease without diabetes mellitus. APPROACH AND RESULTS: This was an investigator-initiated, double-blind, randomized, placebo-controlled trial recruiting adult subjects from the community. Eligible subjects without diabetes mellitus (fasting plasma glucose < 7 mmol/L and HbA1c < 6.5%) who had magnetic resonance imaging-proton density fat fraction (MRI-PDFF) ≥ 5% were randomly allocated to receive empagliflozin 10 mg daily or placebo (1:1 ratio) for 52 weeks (end of treatment, EOT). MRI-PDFF was conducted at baseline and EOT. The primary outcome was the difference in change of MRI-PDFF between the 2 groups at EOT. Secondary outcomes were hepatic steatosis resolution (MRI-PDFF < 5%), alanine aminotransferase drop ≥ 17 U/L, MRI-PDFF decline ≥ 30%, a combination of both, and changes of anthropometric and laboratory parameters at EOT. All outcomes were based on intention-to-treat analysis. Of 98 recruited subjects (median age: 55.7 y [IQR:49.5-63.4]; male:54 [55.1%]), 97 (empagliflozin:49, placebo:48; median MRI-PDFF:9.7% vs 9.0%) had MRI-PDFF repeated at EOT. The Empagliflozin group had a greater reduction in median MRI-PDFF compared to the placebo group (-2.49% vs. -1.43%; p = 0.025), with a nonsignificant trend of resolution of hepatic steatosis (44.9% vs. 28.6%; p = 0.094). There was no significant difference in alanine aminotransferase drop ≥ 17 U/L (16.3% vs. 12.2%; p = 0.564), MRI-PDFF drop ≥ 30% (49.0% vs. 40.8%; p = 0.417), and composite outcome (8.2% vs. 8.2%; p = 1.000). Empagliflozin group had a greater drop in body weight (-2.7 vs. -0.2 kg), waist circumference (-2.0 vs. 0 cm), fasting glucose (-0.3 vs. 0 mmol/L), and ferritin (-126 vs. -22 pmol/L) (all p < 0.05). CONCLUSIONS: Empagliflozin for 52 weeks reduces hepatic fat content in subjects with nondiabetic metabolic dysfunction-associated steatotic liver disease. (ClinicalTrials.gov Identifier: NCT04642261).

Vonoprazan Dual or Triple Therapy Versus Bismuth-Quadruple Therapy as First-Line Therapy for Helicobacter pylori Infection: A Three-Arm, Randomized Clinical Trial.

BACKGROUND: We compared efficacy of vonoprazan-dual or triple therapies and bismuth-quadruple therapy for treatment-naive Helicobacter pylori (HP) infection in Southern China, where primary resistance rates of clarithromycin and levofloxacin are >30%. METHODS: This was an investigator-initiated, three-arm, randomized clinical trial in Southern China. Between March 2022 and August 2023, treatment-naïve HP-infected adults were randomly assigned to receive one of three 14-day regimens (1:1:1 ratio): vonoprazan-dual (VA-dual; vonoprazan 20 mg twice daily and amoxicillin 1 g thrice daily), vonoprazan-triple (VAC-triple; vonoprazan 20 mg/amoxicillin 1 g/clarithromycin 500 mg twice daily), or bismuth-quadruple therapy containing bismuth, esomeprazole, tetracycline, and metronidazole. Primary outcome was noninferiority in HP eradication, evaluated by UBT 4-6 weeks post-treatment by intention-to-treat (ITT) and per-protocol (PP) analysis (based on subjects who completed 14-day treatment and rechecked UBT). Bonferroni-adjusted p-value of <0.017 was used to determine statistical significance. RESULTS: A total of 298 subjects (mean age: 35.7 ± 8.4 years; male: 134 [45.0%]; VC-dual: 100, VAC-triple: 98, bismuth-quadruple: 100) were enrolled, and 292 (98.0%) had UBT rechecked. ITT analysis showed that both VA-dual (eradication rate of 96.0%) and VAC-triple therapies (95.9%) were noninferior to bismuth-quadruple therapy (92.0%) (difference: 4.0%, 95% CI: -2.9% to 11.5%, p < 0.001; and 3.9%, 95% CI: -3.1% to 11.5%, p < 0.001, respectively). PP analysis also revealed noninferiority (96.7% or 96.7% vs. 97.4%, with difference: -2.9% and -2.9%, p = 0.009 and 0.010, respectively). The frequency of adverse events was 39.0%, 56.1%, and 71.0% in VA-dual, VAC-triple, and bismuth-quadruple therapies, respectively. CONCLUSIONS: VA-dual and VA-triple therapies are highly effective and noninferior to bismuth-quadruple therapy in Southern China. Given the lower adverse effects and fewer antibiotic use, VA-dual therapy is the preferred first-line treatment for HP infection. TRIAL REGISTRATION: Chinese Clinical Trial Registry (No. ChiCTR2200056375). Registered on February 4, 2022, https://www.chictr.org.cn/showproj.aspx?proj=14131.

The Predictive Value of Gut Microbiota Composition for Sustained Immunogenicity following Two Doses of CoronaVac.

CoronaVac immunogenicity decreases with time, and we aimed to investigate whether gut microbiota associate with longer-term immunogenicity of CoronaVac. This was a prospective cohort study recruiting two-dose CoronaVac recipients from three centres in Hong Kong. We collected blood samples at baseline and day 180 after the first dose and used chemiluminescence immunoassay to test for neutralizing antibodies (NAbs) against the receptor-binding domain (RBD) of wild-type SARS-CoV-2 virus. We performed shotgun metagenomic sequencing performed on baseline stool samples. The primary outcome was the NAb seroconversion rate (seropositivity defined as NAb ≥ 15AU/mL) at day 180. Linear discriminant analysis [LDA] effect size analysis was used to identify putative bacterial species and metabolic pathways. A univariate logistic regression model was used to derive the odds ratio (OR) of seropositivity with bacterial species. Of 119 CoronaVac recipients (median age: 53.4 years [IQR: 47.8-61.3]; male: 39 [32.8%]), only 8 (6.7%) remained seropositive at 6 months after vaccination. Bacteroides uniformis (log10LDA score = 4.39) and Bacteroides eggerthii (log10LDA score = 3.89) were significantly enriched in seropositive than seronegative participants. Seropositivity was associated with B. eggerthii (OR: 5.73; 95% CI: 1.32-29.55; p = 0.022) and B. uniformis with borderline significance (OR: 3.27; 95% CI: 0.73-14.72; p = 0.110). Additionally, B. uniformis was positively correlated with most enriched metabolic pathways in seropositive vaccinees, including the superpathway of adenosine nucleotide de novo biosynthesis I (log10LDA score = 2.88) and II (log10LDA score = 2.91), as well as pathways related to vitamin B biosynthesis, all of which are known to promote immune functions. In conclusion, certain gut bacterial species (B. eggerthii and B. uniformis) and metabolic pathways were associated with longer-term CoronaVac immunogenicity.

Antibiotic Resistance, Susceptibility Testing and Stewardship in Helicobacter pylori Infection.

Despite the declining trend of Helicobacter pylori (H. pylori) prevalence around the globe, ongoing efforts are still needed to optimize current and future regimens in view of the increasing antibiotic resistance. The resistance of H. pylori to different antibiotics is caused by different molecular mechanisms, and advancements in sequencing technology have come a far way in broadening our understanding and in facilitating the testing of antibiotic susceptibility to H. pylori. In this literature review, we give an overview of the molecular mechanisms behind resistance, as well as discuss and compare different antibiotic susceptibility tests based on the latest research. We also discuss the principles of antibiotic stewardship and compare the performance of empirical therapies based on up-to-date resistance patterns and susceptibility-guided therapies in providing effective H. pylori treatment. Studies and clinical guidelines should ensure that the treatment being tested or recommended can reliably achieve a pre-agreed acceptable level of eradication rate and take into account the variations in antibiotic resistance across populations. Local, regional and international organizations must work together to establish routine antibiotic susceptibility surveillance programs and enforce antibiotic stewardship in the treatment of H. pylori, so that it can be managed in a sustainable and efficient manner.

Baseline Gut Microbiota Was Associated with Long-Term Immune Response at One Year Following Three Doses of BNT162b2.

BACKGROUND: This study explored neutralizing IgG antibody levels against COVID-19 decline over time post-vaccination. We conducted this prospective cohort study to investigate the function of gut microbiota in the host immune response following three doses of BNT162b2. METHODS: Subjects who received three doses of BNT162b2 were recruited from three centers in Hong Kong. Blood samples were obtained before the first dose and at the one-year timepoint for IgG ELISA to determine the level of neutralizing antibody (NAb). The primary outcome was a high immune response (NAb > 600 AU/mL). We performed shotgun DNA metagenomic sequencing on baseline fecal samples to identify bacterial species and metabolic pathways associated with high immune response using linear discriminant analysis effect size analysis. RESULTS: A total of 125 subjects were recruited (median age: 52 years [IQR: 46.2-59.0]; male: 43 [34.4%]), and 20 were regarded as low responders at the one-year timepoint. Streptococcus parasanguinis (log10LDA score = 2.38, p = 0.003; relative abundance of 2.97 × 10-5 vs. 0.03%, p = 0.001), Bacteroides stercoris (log10LDA score = 4.29, p = 0.024; relative abundance of 0.14% vs. 2.40%, p = 0.014) and Haemophilus parainfluenzae (log10LDA score = 2.15, p = 0.022; relative abundance of 0.01% vs. 0, p = 0.010) were enriched in low responders. Bifidobacterium pseudocatenulatum (log10LDA score = 2.99, p = 0.048; relative abundance of 0.09% vs. 0.36%, p = 0.049) and Clostridium leptum (log10LDA score = 2.38, p = 0.014; relative abundance of 1.2 × 10-5% vs. 0, p = 0.044) were enriched in high responders. S. parasanguinis was negatively correlated with the superpathway of pyrimidine ribonucleotides de novo biosynthesis (log10LDA score = 2.63), which contributes to inflammation and antibody production. H. parainfluenzae was positively correlated with pathways related to anti-inflammatory processes, including the superpathway of histidine, purine, and pyrimidine biosynthesis (log10LDA score = 2.14). CONCLUSION: Among three-dose BNT162b2 recipients, S. parasanguinis, B. stercoris and H. parainfluenzae were associated with poorer immunogenicity at one year, while B. pseudocatenulatum and C. leptum was associated with a better response.

Association between Gut Microbiota Composition and Long-Term Vaccine Immunogenicity following Three Doses of CoronaVac.

BACKGROUND: Neutralizing antibody level wanes with time after COVID-19 vaccination. We aimed to study the relationship between baseline gut microbiota and immunogenicity after three doses of CoronaVac. METHODS: This was a prospective cohort study recruiting three-dose CoronaVac recipients from two centers in Hong Kong. Blood samples were collected at baseline and one year post-first dose for virus microneutralization (vMN) assays to determine neutralization titers. The primary outcome was high immune response (defined as with vMN titer ≥ 40). Shotgun DNA metagenomic sequencing of baseline fecal samples identified potential bacterial species and metabolic pathways using Linear Discriminant Analysis Effect Size (LEfSe) analysis. Univariate and multivariable logistic regression models were used to identify high response predictors. RESULTS: In total, 36 subjects were recruited (median age: 52.7 years [IQR: 47.9-56.4]; male: 14 [38.9%]), and 18 had low immune response at one year post-first dose vaccination. Eubacterium rectale (log10LDA score = 4.15, p = 0.001; relative abundance of 1.4% vs. 0, p = 0.002), Collinsella aerofaciens (log10LDA score = 3.31, p = 0.037; 0.39% vs. 0.18%, p = 0.038), and Streptococcus salivarius (log10LDA score = 2.79, p = 0.021; 0.05% vs. 0.02%, p = 0.022) were enriched in low responders. The aOR of high immune response with E. rectale, C. aerofaciens, and S. salivarius was 0.03 (95% CI: 9.56 × 10-4-0.32), 0.03 (95% CI: 4.47 × 10-4-0.59), and 10.19 (95% CI: 0.81-323.88), respectively. S. salivarius had a positive correlation with pathways enriched in high responders like incomplete reductive TCA cycle (log10LDA score = 2.23). C. aerofaciens similarly correlated with amino acid biosynthesis-related pathways. These pathways all showed anti-inflammation functions. CONCLUSION: E. rectale,C. aerofaciens, and S. salivarius correlated with poorer long-term immunogenicity following three doses of CoronaVac.

Association between Gut Microbiota and SARS-CoV-2 Infection and Vaccine Immunogenicity.

Gut microbiota is increasingly recognized to play a pivotal role in various human physiological functions and diseases. Amidst the COVID-19 pandemic, research has suggested that dysbiosis of the gut microbiota is also involved in the development and severity of COVID-19 symptoms by regulating SARS-CoV-2 entry and modulating inflammation. Previous studies have also suggested that gut microbiota and their metabolites could have immunomodulatory effects on vaccine immunogenicity, including influenza vaccines and oral rotavirus vaccines. In light of these observations, it is possible that gut microbiota plays a role in influencing the immune responses to COVID-19 vaccinations via similar mechanisms including effects of lipopolysaccharides, flagellin, peptidoglycan, and short-chain fatty acids. In this review, we give an overview of the current understanding on the role of the gut microbiota in COVID-19 manifestations and vaccine immunogenicity. We then discuss the limitations of currently published studies on the associations between gut microbiota and COVID-19 vaccine outcomes. Future research directions shall be focused on the development of microbiota-based interventions on improving immune response to SARS-CoV-2 infection and vaccinations.