• Test performed on small bowel mucosal biopsy obtained at endoscopy.
• Lactase deficiency is common, with prevalence up to 90%, depending on ethnic background.

• Testing for other related disaccharidase deficiencies, such as:
  • Sucrase-isomaltase deficiency
  • Glucoamylase deficiency (may present as irritable bowel syndrome)
  • Maltase deficiency
• Multiple deficiencies are seen in conditions leading to mucosal injury:
  • Viral, bacterial or protozoal infections
  • Post-infectious enteritis
  • Small intestinal bacterial overgrowth (SIBO)
  • Allergic enteropathy
  • Celiac disease
  • Crohn’s disease
  • NSAID enteropathy

• Test performed on pancreatic fluid obtained at endoscopy after pancreatic stimulation with cholecystokinin (CCK) or secretin
• Only 0.5 ml of fluid is required for analysis of amylase, lipase, trypsin, chymotrypsin and elastase using single or multiple fluids
• Low pancreatic enzyme activity can be the consequence of:
  • Pancreatic damage
    • Chronic pancreatitis
    • Cystic fibrosis
  • An isolated enzyme deficiency
    • Transient (in the first 5-6 months of life)
    • Permanent (congenital enzyme deficiency)

• Sample collected from tracheal washing or bronchial lavage (BAL)
• Pepsin A presence is specifically determined. Gastric pepsin detected in the airway of patients is an indicator of pulmonary aspiration. The presence of amylase in airway fluid is indicative of microaspiration of oral fluid.

Congenital Sucrase-Isomaltase Deficiency (CSID) genetic test by next-generation sequencing (NGS) of clinical specimens, including, but not limited to biopsies, biopsy homogenates, buccal swabs, FFPE tissue sections, etc. CSID genetic test detects mutations in the entire sucraseisomaltase (SI) gene. This will identify all known, unknown or potentially significant pathogenic SI gene variants including heterozygous, compound heterozygous or homozygous mutations.

The small intestine and stomach are generally sterile or may contain low numbers of bacterial cells. If the number of cultivable bacteria in the small intestine exceeds 104 CFU/ml, then it manifests the small intestinal microbial overgrowth (SIBO/SIMO) condition.

SIBO/SIMO may cause:

• Malabsorption of various nutrients (like fat and vitamins)
• Destruction of the surface layer
• Protein loss
• Anemia
• Diarrhea
• Irritable bowel syndrome (IBS)

Sample is a brushing of the mucosal layer from the small intestine.

• Eosinophil activation plays an important role in inflammatory processes in allergic diseases, including eosinophilic esophagitis (EoE).
• Upon activation, eosinophils secrete several cationic proteins, including eosinophil-derived neurotoxin (EDN), a glycosylated single-chain protein.
• EDN is detected by ELISA in esophageal brushing samples to diagnose and monitor EoE.

• Assessment of small intestinal absorption and barrier function in the bowel
• Intestinal permeability or leaky gut has been observed in inflammatory bowel disease (IBD) and food allergy
• Lactulose-Mannitol assay measures the ability of these two non-metabolized sugar molecules to permeate the intestinal mucosa