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

BACKGROUND AND AIMS: We investigated whether empagliflozin reduces hepatic steatosis in metabolic-dysfunction associated steatotic liver disease (MASLD) patients without diabetes mellitus (DM). APPROACH AND RESULTS: This was an investigator-initiated, double-blind, randomized, placebo-controlled trial recruiting adult subjects from the community. Eligible subjects without DM (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. Primary outcome was difference in change of MRI-PDFF between two groups at EOT. Secondary outcomes were hepatic steatosis resolution (MRI-PDFF <5%), ALT drop≥17U/L, MRI-PDFF decline≥30%, 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. Empagliflozin group had greater reduction in median MRI-PDFF compared to placebo group (-2.49% vs -1.43%;p=0.025), with a non-significant trend of resolution of hepatic steatosis (44.9% vs 28.6%;p=0.094). There was no significant difference in ALT drop≥17U/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 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 non-diabetic MASLD subjects. (ClinicalTrials.gov Identifier: NCT04642261).

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.

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.