Patients with functional bowel disorder have disaccharidase deficiency: A single-center study from Russia

ARTICLE HIGHLIGHTS

Research background

Functional bowel disorder (FBD) clinically manifests as changes in stool frequency and consistency, sometimes accompanied by abdominal pain associated with defecation. FBDs are a very common in modern society. Many patients report an association their symptoms with the consumption foods that containing carbohydrates.

Research motivation

Few studies have been conducted on intestinal disaccharidase activity. Most of these studies have been on lactase activity in both adults and children and sucrase activity in children. Maltase and glucoamylase activities have not been studied in adults.

Research objectives

The aim of this study was to determine the value of intestinal disaccharidases glucoamylase, maltase, sucrase, and lactase in understanding the etiology and pathogenesis of FBDs.

Research methods

When collecting data for anamnesis, specific attention was paid to food tolerance/ intolerance and the effect of food on gastrointestinal (GI) symptoms. Laboratory and instrumental research methods were conducted within the scope of standards and algorithms used for the diagnosis of FBD. Instrumental studies, in addition to X-ray enterography, colonoscopy, and diagnostic ultrasound of the abdominal organs, also included esophagogastroscopy with duodenum biopsy (3-5 specimens). Biochemical evaluation of intestinal (membrane) disaccharidase activity and histological evaluation of the duodenal mucosa were performed as well. In the histological preparations, the height of the intestinal villi, depth of the crypts, and their ratio were evaluated. In preparations stained with the periodic-acid Schiff reaction, the state of the brush border of the enterocytes was evaluated, with attention paid to their presence in the epithelium of goblet cells and intraepithelial lymphocytes, as well as in Paneth cells located at the base of the crypts. The activities of the carbohydrate-splitting enzymes lactase, glucoamylase, sucrase and maltase were determined by the Dahlqvist method.

Research results

In 78 of the 82 patients with FBD, GI symptoms were associated with disaccharidase deficiency, which developed after acute enteric infections, antibiotic therapy, non-steroidal anti-inflammatory drugs, or other damaging agents. Decreased activity of membrane digestion enzymes was observed in most patients. Therefore, additional studies are necessary to determine the contribution of these enzymes to the symptoms associated with FBD.

Research conclusions

Our study indicates that the mechanism underlying FBD may be as follows. Damage to the mucous membrane of the small intestine leads to a decrease in the activity of enzymes on the brush border of enterocytes, resulting in disorders of carbohydrate hydrolysis and accumulation of osmoactive substances in the lumen of the small intestine. In turn, small intestinal bacterial overgrowth, stool disorder, abdominal pain, and bloating occurs. Additional diagnostic methods should be explored for patients with FBD.

Research perspectives

A detailed study of this phenomenon would make it possible to create drugs that compensate for the deficiency of enzymes or stimulate their synthesis, which would significantly improve the treatment of patients with FBD.