Siew C Ng

• MBBS (Lon), FRCP (Lond, Edin), PhD (Lond), FHKCP, FHKAM (Med)
• Professor (Full) at Chinese University of Hong Kong

Next-generation live biotherapeutics are promising to aid the treatment of obesity and metabolic diseases. Here, we reported a novel anti-obesity probiotic candidate, Roseburia hominis, that was depleted in stool samples of obese subjects compared with lean controls, and its abundance was negatively correlated with body mass index and serum triglyc...

Background Etrasimod is an oral, once‐daily (q.d.), selective sphingosine 1‐phosphate (S1P)1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis (UC). Unlike the S1P receptor modulator ozanimod, etrasimod does not have a molecular structure to inhibit monoamine oxidase (MAO). Coadministration of drugs that i...

Post-acute coronavirus disease 2019 syndrome (PACS), following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19), is typically characterized by long-term debilitating symptoms affecting multiple organs and systems. Unfortunately, there is currently a lack of effective treatment strategies....

Increased hygiene and sanitation are theorized to predispose to developing atopic diseases, a process potentially mediated by the gut microbiome. We hypothesized that the gut microbiome maturation has been altered by COVID-19 lockdown measures during the first year of life, a critical period when environmental exposure shapes human microbiome devel...

Introduction Long‐term data on metachronous advanced adenoma (AA) recurrence after endoscopic submucosal dissection (ESD) remain scarce, leading to a lack of a standardized surveillance strategy. This study aims to evaluate the long‐term risk of recurrent AA after ESD. Materials and Methods A longitudinal retrospective cohort study with propensity...

Association between ileal colonization by Adherent-Invasive Escherichia coli (AIEC) and Crohn’s disease (CD) has been widely described in high-incidence Western countries but remains unexplored in Asian countries with a fast increase in CD incidence. In the PACIFIC study, we compared the characteristics of AIEC pathobionts retrieved from ileal biop...

The reproducibility in microbiome studies is limited due to the lack of one gold-standard operating procedure. The aim of this study was to examine the impact of protocol variations on microbiome composition using metagenomic data sets from a single center. We assessed the variation in a data set consisted of 2,722 subjects, including 9 subcohorts...

Accumulating evidence suggests that gut microbiota alterations influence brain function and could serve as diagnostic biomarkers and therapeutic targets. The potential of using fecal microbiota signatures to aid autism spectrum disorder (ASD) detection is still not fully explored. Here, we assessed the potential of different levels of microbial mar...

Objective To update the global burden of Inflammatory Bowel Disease (IBD) using data from the Global Burden of Disease ( GBD ) 2021. Methods Data from GBD 2021 were analyzed to assess the IBD burden. Results In 2021, there were 375,140 new cases and 3.83 million total cases of IBD. Elderly-onset IBD accounted for 11% of incidences. 167 countries...

Background Fusobacterium nucleatum (F. nucleatum) is one of the key tumorigenic bacteria in colorectal cancer (CRC), yet how F. nucleatum is involved in colorectal cancer carcinogenesis remains unknown. Results In the present study, we carried out PathSeq analysis on RNA sequencing data from the 430 primary colon adenocarcinomas in TCGA database t...

Background Emerging data demonstrate the altered gut microbiome is implicated in the development and progression of colorectal neoplasia. A panel of fecal bacteria gene markers (Fusobacterium nucleaum, Fn; Bacteroides clarus, Bc; Clostridium hathewayi, Ch; and Lachnoclostridium, m3) has been identified as a non-invasive biomarker for the detection...

High-fat, low-fiber Western-style diets (WD) induce microbiome dysbiosis characterized by reduced taxonomic diversity and metabolic breadth, which in turn increases risk for a wide array of metabolic, immune and systemic pathologies. Recent work has established that WD can impair microbiome resilience to acute perturbations like antibiotic treatmen...

Objective The specific breast milk-derived metabolites that mediate host–microbiota interactions and contribute to the onset of atopic dermatitis (AD) remain unknown and require further investigation. Design We enrolled 250 mother–infant pairs and collected 978 longitudinal faecal samples from infants from birth to 6 months of age, along with 243...

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that often coincides with gut dysbiosis. Studies show that alterations in gut microbiota influence brain function and could serve as diagnostic biomarkers and therapeutic targets. This forum article discusses the role of gut microbiota in ASD pathogenesis and its diagnostic an...

Associations between the gut microbiome and autism spectrum disorder (ASD) have been investigated although most studies have focused on the bacterial component of the microbiome. Whether gut archaea, fungi and viruses, or function of the gut microbiome, is altered in ASD is unclear. Here we performed metagenomic sequencing on faecal samples from 1,...

The impact of gestational diabetes mellitus (GDM) on maternal or infant microbiome trajectory remains poorly understood. Utilizing large-scale longitudinal fecal samples from 264 mother-baby dyads, we present the gut microbiome trajectory of the mothers throughout pregnancy and infants during the first year of life. GDM mothers had a distinct micro...

The gut fungi play important roles in human health and are involved in energy metabolism. This study aimed to examine gut mycobiome composition in obese subjects in two geographically different regions in China and to identify specific gut fungi associated with obesity. A total of 217 subjects from two regions with different urbanization levels [Ho...

Fibrostenosis of the small bowel is common in patients with Crohn's disease. No consensus recommendations on definition, diagnosis and management in clinical practice are currently available. In this Consensus Statement, we present a clinical practice RAND/UCLA appropriateness study on the definition, diagnosis and clinical management of fibrosteno...

Background and Aims Tofacitinib is an oral Janus kinase inhibitor for the treatment of ulcerative colitis (UC). We report an integrated summary of tofacitinib safety from the completed global UC clinical program (9.2 years maximum tofacitinib exposure). Methods This analysis included patients receiving tofacitinib 5 or 10 mg twice daily (b.i.d.) f...

Inflammatory bowel disease (IBD) is rapidly emerging in the Asia Pacific region. However, there are many challenges in the diagnosis and management of this condition. The Asian Pacific Association of Gastroenterology (APAGE) Working Group on IBD conducted a round table meeting to identify 10 common mistakes in the management of IBD in Asia. To summ...

The mechanisms underlying the many phenotypic manifestations of post-acute COVID-19 syndrome (PACS) are poorly understood. Herein, we characterized the gut microbiome in heterogenous cohorts of subjects with PACS and developed a multi-label machine learning model for using the microbiome to predict specific symptoms. Our processed data covered 585...

Childhood obesity is linked to maternal smoking during pregnancy. Gut microbiota may partially mediate this association and could be potential targets for intervention; however, its role is understudied. We included 1,592 infants from the Canadian Healthy Infants Longitudinal Development Cohort. Data on environmental exposure and lifestyle factors...

The incidence and prevalence of inflammatory bowel disease (IBD), namely Crohn's disease and ulcerative colitis, have increased in Latin America over the past few decades. Although incidence is accelerating in some countries in the region, other areas in Latin America are already transitioning into the next epidemiological stage-ie, compounding pre...

Emerging evidence suggests autism spectrum disorder (ASD) is associated with altered gut bacteria. However, less is known about the gut viral community and its role in shaping microbiota in neurodevelopmental disorders. Herein, we perform a metagenomic analysis of gut-DNA viruses in 60 children with ASD and 64 age- and gender-matched typically deve...

BACKGROUND Rising incidence and prevalence of inflammatory bowel disease (IBD) observed historically in early-industrialized regions now also appear in newly-industrialized and emerging regions. The epidemiology of IBD has been proposed to progress across epidemiologic stages: 1. Emergence (low incidence and prevalence); 2. Acceleration in Incidenc...

BACKGROUND A theoretical framework for population-level transition across four epidemiologic stages has been proposed for inflammatory bowel disease (IBD): 1. Emergence (low incidence/prevalence); 2. Acceleration in Incidence (rapid rising incidence); 3. Compounding Prevalence (stabilizing incidence, rapid rising prevalence); and 4. Prevalence Equi...

BACKGROUND Epidemiologic stages of inflammatory bowel disease (IBD) have been proposed: 1. Emergence (low incidence and prevalence); 2. Acceleration in Incidence (rapidly rising incidence, low prevalence); and 3. Compounding Prevalence (stabilizing incidence, rapidly rising prevalence). To date, these stages have been theoretical without quantified...

BACKGROUND Early-industrialized regions (e.g., North America, Europe, Oceania) are currently in stage 3 of the epidemiologic evolution of inflammatory bowel disease (IBD), compounding prevalence wherein incidence stabilizes, but prevalence rises rapidly. This epidemiologic stage predicts the trajectory of healthcare infrastructure needs over the co...

Background Tofacitinib is an oral Janus kinase inhibitor for the treatment of UC. This analysis assessed the impact of cigarette smoking on tofacitinib efficacy and safety in the UC clinical program. Methods Efficacy endpoints and adverse events (AEs) were evaluated by smoking status (ever smokers [current and ex-smokers] and never smokers) in the...

Context Despite recent advances in antidepressants in treating major depression (MDD), their usage is marred by adverse effects and social stigmas. Probiotics may be an efficacious adjunct or standalone treatment, potentially circumventing the aforementioned issues with antidepressants. However, there is a lack of head-to-head clinical trials betwe...

During the 20th century, inflammatory bowel disease (IBD) was considered a disease of early-industrialized regions in North America, Europe, and Oceania. At the turn of the 21st century, incidence of IBD increased in newly-industrialized and emerging regions in Africa, Asia, and Latin America, while prevalence in early-industrialized regions starte...

The early-life period is one of microbiome establishment and immune maturation. Early-life exposures are increasingly being recognised to play an important role in IBD risk. The composition of functions of the gut microbiome in the prenatal, perinatal, and postnatal period may be crucial towards development of health or disease, including IBD, late...

Summary Background Post-acute COVID-19 syndrome (PACS) affects over 65 million individuals worldwide but treatment options are scarce. We aimed to assess a synbiotic preparation (SIM01) for the alleviation of PACS symptoms. Methods In this randomised, double-blind, placebo-controlled trial at a tertiary referral centre in Hong Kong, patients with P...

Background Primary sclerosing cholangitis is a chronic liver disease associated with significant morbidity, mortality, and healthcare utilization. We conducted a systematic review and meta-analysis of population-based studies of the incidence and prevalence of primary sclerosing cholangitis. Methods Medline and Embase were systematically searched...

LINKED CONTENT This article is linked to Yau et al papers. To view these articles, visit https://doi.org/10.1111/apt.17703 and https://doi.org/10.1111/apt.17724

The role of gut microbiota in modulating the durability of COVID-19 vaccine immunity is yet to be characterised. In this cohort study, we collected blood and stool samples of 121 BNT162b2 and 40 CoronaVac vaccinees at baseline, 1 month, and 6 months post vaccination (p.v.). Neutralisation antibody, plasma cytokine and chemokines were measured and a...

Introduction Emerging preclinical and clinical studies suggest that altered gut microbiome composition and functions are associated with coronavirus 2019 (COVID- 19) severity and its long-term complications. We hypothesize that COVID-19 outcome is associated with gut microbiome status in population-based settings. Methods Gut metagenomic data of t...

Background Faecal microbiota transplantation (FMT) has been shown to improve symptoms in a proportion of patients with irritable bowel syndrome (IBS). Aim We performed a randomised trial to assess the efficacy of FMT in patients with IBS. Methods We randomised 56 patients with diarrhoea‐predominant IBS 1:1 to FMT or placebo via the duodenal route...

Background and aims: Patients with inflammatory bowel disease have increased risk of atherosclerotic cardiovascular [CV] disease [ASCVD]. Tofacitinib is an oral small molecule Janus kinase inhibitor for treatment of ulcerative colitis [UC]. We report major adverse CV events [MACE] in the UC OCTAVE programme, stratified by baseline CV risk. Method...

Background: There is a rapid increase in the incidence of inflammatory bowel diseases (IBD) in newly industrialized countries, yet epidemiological data is incomplete. We herein report the methodology adopted to study the incidence of IBD in newly industrialized countries and to evaluate the effect of environmental factors including diet on IBD dev...

Gut microbiota is believed to be a major determinant of health outcomes. We hypothesised that a novel oral microbiome formula (SIM01) can reduce the risk of adverse health outcomes in at-risk subjects during the coronavirus disease 2019 (COVID-19) pandemic. In this single-centre, double-blind, randomised, placebo-controlled trial, we recruited subj...

Newborns can acquire immunological protection to SARS-CoV-2 through vaccine-conferred antibodies in human breast milk. However, there are some concerns around lactating mothers with regards to potential short- and long-term adverse events and vaccine-induced changes to their breast milk microbiome composition, which helps shape the early-life micro...

Screening for colorectal cancer (CRC) is effective in reducing CRC related mortality. Current screening methods include endoscopy based and biomarker based approaches. This guideline is a joint official statement of the Asian Pacific Association of Gastroenterology (APAGE) and the Asian Pacific Society of Digestive Endoscopy (APSDE), developed in r...

The cost of caring for patients with inflammatory bowel disease (IBD) continues to increase worldwide. The cause is not only a steady increase in the prevalence of Crohn's disease and ulcerative colitis in both developed and newly industrialised countries, but also the chronic nature of the diseases, the need for long-term, often expensive treatmen...

Food additives have been linked to the pro-inflammatory microbial dysbiosis associated with Crohn’s disease (CD) but the underlying ecological dynamics are unknown. Here, we examine how selection of food additives affects the growth of multiple strains of a key beneficial bacterium (Faecalibacterium prausnitzii), axenic clinical isolates of proinfl...

Background There is insufficient knowledge about the key characteristics of the pathogenic and protective bacteria in inflammatory bowel disease. The ENIGMA study aimed to identify the phylogenetic and functional characteristics of Faecalibacterium prausnitzii, considered a protective “anti-inflammatory” bacterium, in both health and Crohn’s diseas...

Background Deep functional understanding of the mucosa-associated microbiota (MAM) in Crohn’s disease and health by DNA sequencing approaches is restricted by the dominance of human DNA in samples. We established an ex vivo combination of tissue preservation, microbe culture, and metagenomic sequencing to overcome this knowledge gap1 and applied th...

Background Gut microbial dysbiosis and dysregulated host immune responses are key factors implicated in Crohn’s disease pathogenesis. However, the nexus between the mucosa-associated microbiota (MAM) and epithelial cell immune response(s) remains poorly understood. Here, we used in vitro cultures of LS174T human epithelial cells to examine the infl...

Background Crohn’s disease (CD) and ulcerative colitis (UC), together known as inflammatory bowel diseases (IBD), affect approximately seven million people globally. The continuous rise in IBD prevalence and the aging of populations will inevitably lead to an increasing use of health care resources. In parallel with these trends, continuing innovat...

Simple Summary There is a scarcity of economic analysis on the use of non-invasive biomarkers to inform policy-making with respect to their application in population-based colorectal cancer (CRC) screening programs. The objective of this study is to conduct a comparative cost-effectiveness analysis on using M3CRC (m3 + Fn + Ch + Bc + FIT) as a prim...

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesopha...

Irritable bowel syndrome (IBS) is a heterogeneous condition with multifactorial pathogenesis. We studied deeply phenotyped individuals with microbiota sequencing enrolled in the American Gut Project. The IBS subjects were matched by age, gender, body mass index, geography, and dietary patterns with non-IBS controls. A total of 942 subjects with IBS...

Inflammatory bowel disease (IBD) is a chronic immune‐mediated intestinal disease consisting of ulcerative colitis and Crohn's disease. Inflammatory bowel disease is believed to be developed as a result of interactions between environmental, immune‐mediated and microbial factors in a genetically susceptible host. Recent advances in high‐throughput s...