Oral Microbiome of Crohn's Disease Patients With and Without Oral Manifestations

BACKGROUND AND AIMS

Microbiome dysbiosis is associated with inflammatory destruction in Crohn's disease [CD]. Although gut microbiome dysbiosis is well established in CD, the oral microbiome is comparatively under-studied. This study aims to characterize the oral microbiome of CD patients with/without oral manifestations.

METHODS

Patients with CD were recruited with age-, gender- and race-matched controls. Potential confounders such as dental caries and periodontal condition were recorded. The oral microbiome was collected using saliva samples. Microbial DNA was extracted and sequenced using shotgun sequencing. Metagenomic taxonomic and functional profiles were generated and analysed.

RESULTS

The study recruited 41 patients with CD and 24 healthy controls. Within the CD subjects, 39.0% had oral manifestations with the majority presenting with cobblestoning and/or oral ulcers. Principal coordinate analysis demonstrated distinct oral microbiome profiles between subjects with and without CD, with four key variables responsible for overall oral microbiome variance: [1] diagnosis of CD, [2] concomitant use of steroids, [3] concomitant use of azathioprine and 4] presence of oral ulcers. Thirty-two significant differentially abundant microbial species were identified, with the majority associated with the diagnosis of CD. A predictive model based on differences in the oral microbiome found that the oral microbiome has strong discriminatory function to distinguish subjects with and without CD [AUROC 0.84]. Functional analysis found that an increased representation of microbial enzymes [n = 5] in the butyrate pathway was positively associated with the presence of oral ulcers.

CONCLUSIONS

The oral microbiome can aid in the diagnosis of CD and its composition was associated with oral manifestations.

Ectopic gut colonization: a metagenomic study of the oral and gut microbiome in Crohn's disease

BACKGROUND

This study aims to characterize, the gut and oral microbiome in Asian subjects with Crohn's disease (CD) using whole genome shotgun sequencing, thereby allowing for strain-level comparison.

METHODS

A case-control study with age, sex and ethnicity matched healthy controls was conducted. CD subjects were limited to well-controlled patients without oral manifestations. Fecal and saliva samples were collected for characterization of gut and oral microbiome respectively. Microbial DNA were extracted, libraries prepared and sequenced reads profiled. Taxonomic diversity, taxonomic association, strain typing and microbial gene pathway analyses were conducted.

RESULTS

The study recruited 25 subjects with CD and 25 healthy controls. The oral microbe Streptococcus salivarius was found to be enriched and of concordant strains in the gut and oral microbiome of Crohn's disease subjects. This was more likely in CD subjects with higher Crohn's Disease Activity Index (184.3 ± 2.9 vs 67.1 ± 82.5, p = 0.012) and active disease status (Diarrhoea/abdominal pain/blood-in-stool/fever and fatigue) (p = 0.016). Gut species found to be significantly depleted in CD compared to control (Relative abundance: Median[Range]) include: Faecalibacterium prausnitzii (0.03[0.00-4.56] vs 13.69[5.32-18.71], p = 0.010), Roseburia inulinivorans (0.00[0.00-0.03] vs 0.21[0.01-0.53], p = 0.010) and Alistipes senegalensis (0.00[0.00-0.00] vs 0.00[0.00-0.02], p = 0.029). While Clostridium nexile (0.00[0.00-0.12] vs 0.00[0.00-0.00], p = 0.038) and Ruminococcus gnavus (0.43[0.02-0.33] vs 0.00[0.00-0.13], p = 0.043) were found to be enriched. C. nexile enrichment was not found in CD subjects of European descent. Microbial arginine (Linear-discriminant-analysis: 3.162, p = 0.001) and isoprene (Linear-discriminant-analysis: 3.058, p < 0.001) pathways were found at a higher relative abundance level in gut microbiome of Crohn's disease.

CONCLUSIONS

There was evidence of ectopic gut colonization by oral bacteria, especially during the active phase of CD. Previously studied gut microbial differences were detected, in addition to novel associations which could have resulted from geographical/ethnic differences to subjects of European descent. Differences in microbial pathways provide possible targets for microbiome modification.

Identifying Patients With Cirrhosis Who Might Avoid Screening Endoscopy Based on Serum Albumin and Bilirubin and Platelet Counts

The presence of gastroesophageal varices is a major complication of portal hypertension associated with significant morbidity and mortality.¹ The Baveno VI criteria state that patients with liver stiffness measurement (LSM) <20 kPa by transient elastography (TE) and platelet count >150,000/μL can avoid screening endoscopy for high-risk varix (HRV).² However, because TE is not widely available, the Baveno VI criteria could not be applied in many clinical settings. As such, we aim to determine a concise clinical criterion as an alternative noninvasive tool to predict absence of HRV among patients with compensated cirrhosis to avoid screening esophagogastroduodenoscopy (EGD).

Gastric metastases of oral carcinoma resulting from percutaneous endoscopic gastrostomy placement via the introducer technique

INTRODUCTION. Tumour cell implantation is a rare complication in patients with head and neck cancers, who have undergone percutaneous endoscopic gastrostomy (PEG) tube placement. It has not been reported in patients who underwent a PEG insertion via the radiological or introducer technique. We describe a novel case presentation of metastatic disease in a patient who underwent PEG placement via the introducer (Russell) technique which, to the best of our knowledge, has not not previously been described. CASE PRESENTATION. The patient was a 37-year-old Malay woman who developed metastatic squamous cell carcinoma deposits in her stomach and liver one month after a gastrostomy tube was removed following the completion of treatment for oropharyngeal carcinoma. CONCLUSION. Previous authors have advocated the use of alternative PEG insertion technique apart from the 'pull' technique to minimise the risk of tumour implantation from head and neck cancers. Our case report suggests that this risk is not totally eliminated when the PEG tube is inserted via the introducer technique.

Resolution of adefovir-related nephrotoxicity by adefovir dose-reduction in patients with chronic hepatitis B

BACKGROUND

Chronic hepatitis B patients (CHB) treated with adefovir were followed up to evaluate nephrotoxicity and its outcome.

AIM

To assess the incidence of renal dysfunction during adefovir therapy in Asian patients and factors associated with it, and evaluate strategies to improve adefovir-related renal dysfunction and their impact on viral suppression.

METHODS

Chronic hepatitis B clinic patients from a tertiary hospital on adefovir treatment, with their clinical and laboratory parameters were extracted from the hospital electronic clinical database in an observational study design. Patients were excluded if they had liver/renal transplant, baseline renal impairment or were on dialysis. Adefovir-related renal dysfunction was defined as adefovir-related abnormal serum creatinine (ARASC) > 125 μmol/L (males), >90 μmol/L (females); adefovir-related abnormal GFR <60 mL/min; and adefovir-related increased serum creatinine >0.5 mg/dL, without other known causes of nephrotoxicity.

RESULTS

A total of 271/383 adefovir-treated patients were suitable for analysis and 33(12%) patients developed abnormal serum creatinine. Cumulative increase in proportion of patients with ARASC was 33.8% and GFR ≤60 mL/min was 38.3% by 6 years, while serum creatinine increase ≥0.5 mg/dL was 21.48% by 5 years. Using multivariate analysis, the only independent baseline predictor of ARASC was GFR ≤76.1 mL/min. Patients who had ARASC had similar levels of viral suppression to those who did not have ARASC. Those who had ARASC either continued adefovir (24%), switched therapy (24%) or had adefovir dose reduction (52%). ARASC resolved and GFR normalised in almost all patients after either switching therapy or reducing adefovir dose, with no difference between the two strategies (P = 0.737). Those with adefovir dose reduction had no significant increase in HBV DNA (P = 0.170).

CONCLUSIONS

Adefovir-related renal dysfunction occurred in a significant number of adefovir-treated patients, but reduction of the dose led to renal improvement without compromising treatment efficacy.

The lacrimal lens as an assessment factor in hard contact lens fitting

The fitting of hard contact lenses relies primarily on the evaluation of the findings of 'K' readings, the fluorescein pattern of the tear configuration and the interpretation of the lens movement upon blinking and the lens position after blinking. All of these methods have some disadvantages in the evaluation procedure: (a) keratometer readings measure cornical radius in a small and restricted area of the central cornea not in the larger area to eventually be covered by the lens (Bennett and Rabbetts, Clinical Visual Optics. Butterworths, London, UK, pp. 420-421, 1984); (b) the fluorescein pattern is sometimes unreliable especially in the presence of excessive tear flow; (c) lens movement, arguably the most reliable of evaluation methods, nonetheless requires some alternative back-up technique. This presentation outlines the possibility of utilising the lacrimal lens as a useful additional procedure to the above when prescribing a lens curvature of choice. It should be pointed out that the technique discussed refers to spherical or near spherical corneas.