New developments in gastroesophageal reflux disease diagnosis and therapy

Genetic estimation of correlations and causalities between multifaceted modifiable factors and gastro-oesophageal reflux disease

BACKGROUND

Gastro-oesophageal reflux disease (GORD) is a common gastrointestinal dysfunction that significantly affects the quality of daily life, and health interventions are challenging to prevent the risk of GORD. In this study, we used Mendelian randomization framework to genetically determine the causal associations between multifaceted modifiable factors and the risk of GORD.

MATERIALS AND METHODS

Sixty-six exposures with available instrumental variables (IVs) across 6 modifiable pathways were included in the univariable MR analysis (UVMR). Summary-level genome-wide association studies (GWAS) datasets for GORD were retrieved from the Neale Lab (GORD _Neale , Ncases = 29975, Ncontrols = 390556) and FinnGen (GORD _Finn , Ncases = 13141, Ncontrols = 89695). Using the METAL software, meta-analysis for single nucleotide polymorphisms (SNPs) from GORD _Neale and GORD _Finn was conducted with an inverse variance weighted (IVW) fixed-effect model. Moreover, we leveraged partition around medoids (PAM) clustering algorithm to cluster genetic correlation subtypes, whose hub exposures were conditioned for multivariable MR (MVMR) analyses. P-values were adjusted with Bonferroni multiple comparisons.

RESULTS

Significant causal associations were identified between 26 exposures (15 risk exposures and 11 protective exposures) and the risk of GORD. Among them, 13 risk exposures [lifetime smoking, cigarette consumption, insomnia, short sleep, leisure sedentary behavior (TV watching), body mass index (BMI), body fat percentage, whole body fat mass, visceral adipose tissue, waist circumference, hip circumference, major depressive disorder, and anxious feeling], and 10 protective exposures (leisure sedentary behavior (computer use), sitting height, hand grip strength (left and right), birth weight, life satisfaction, positive affect, income, educational attainment, and intelligence) showed novel significant causal associations with the risk of GORD. Moreover, 13 exposures still demonstrated independent associations with the risk of GORD following MVMR analyses conditioned for hub exposures (educational attainment, smoking initiation and BMI). In addition, 12 exposures showed suggestive causal associations with the risk of GORD.

CONCLUSION

This study systematically elucidated the modifiable factors causally associated with the risk of GORD from multifaceted perspectives, which provided implications for prevention and treatment of GORD.

Lactobacillus species shift in distal esophagus of high-fat-diet-fed rats

AIM: To analyze the microbiota shift in the distal esophagus of Sprague-Dawley rats fed a high-fat diet.

METHODS: Twenty Sprague-Dawley rats were divided into high-fat diet and normal control groups of 10 rats each. The composition of microbiota in the mucosa from the distal esophagus was analyzed based on selective culture. A variety of Lactobacillus species were identified by molecular biological techniques. Bacterial DNA from Lactobacillus colonies was extracted, and 16S rDNA was amplified by PCR using bacterial universal primers. The amplified 16S rDNA products were separated by denaturing gradient gel electrophoresis (DGGE). Every single band was purified from the gel and sent to be sequenced.

RESULTS: Based on mucosal bacterial culturing in the distal esophagus, Staphylococcus aureus was absent, and total anaerobes and Lactobacillus species were decreased significantly in the high-fat diet group compared with the normal control group (P < 0.01). Detailed DGGE analysis on the composition of Lactobacillus species in the distal esophagus revealed that Lactobacillus crispatus, Lactobacillus gasseri (L. gasseri) and Lactobacillus reuteri (L. reuteri) comprised the Lactobacillus species in the high-fat diet group, while the composition of Lactobacillus species in the normal control group consisted of L. gasseri, Lactobacillus jensenii and L. reuteri.

CONCLUSION: High-fat diet led to a mucosal microflora shift in the distal esophagus in rats, especially the composition of Lactobacillus species.

The Challenge of Protocols for Reflux Disease

Objectives. Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are very common and controversial diseases. The authors have previously reviewed clinical practice guidelines (CPGs) on reflux disease, and these major consensus statements differ on what constitutes ideal management. The aim is to critically review existing protocols for reflux based on CPG recommendations and to present a refined protocol that may be further used to develop a critical pathway for reflux in ambulatory medical practice.

Study Design. Literature review with discussion.

Methods. A PubMed search was used to identify current clinical protocols or algorithms for reflux disease, and the principal elements of each were compared.

Results. Of the 828 articles identified in the search, 11 met the search criteria. Together with 4 articles previously identified, 15 were analyzed. All protocols discuss the important role of empiric therapy, although with differences in use. Only 5 protocols (33%) were based on systematic review such as CPGs. Eight protocols (53%) used alarm symptoms to prompt a workup. For these patients, upper endoscopy was by far the most common diagnostic method. The use of other modalities varies significantly between protocols. The authors propose a standard protocol based on patient risk factors that employs CPG recommendations and may be used for critical pathway outcomes measures.

Conclusion. There are major differences between existing protocols for reflux disease in the literature, reflecting many clinical controversies. Outcomes of different protocols have not been extensively studied. The authors propose a new protocol that is a synthesis of those reviewed and based on risk stratification.

Symptom check: is it GERD?

Despite the vast number of individuals living with gastroesophageal reflux disease (GERD), establishing a diagnosis can be difficult. Detailed patient history and symptom review are critical. Nurses can play an integral role in gathering information that may lead to a definitive diagnosis. In addition to the classic symptoms of GERD-acid reflux and heartburn-several atypical conditions may also be present. Understanding the diverse and subtle nature of presenting symptoms can assist in establishing a GERD diagnosis. This column examines the atypical presentations of GERD, including laryngopharyngeal symptoms, chronic cough, asthma, and dental erosions.