Chronic kidney disease and gastrointestinal system disturbances

Abstract

Chronic kidney disease (CKD) is a global health problem and is one of the important causes of morbidity and mortality. Gastrointestinal symptoms and gastrointestinal disease are common in patients with CKD. The uremic milieu affects the gastrointestinal tract, and gastrointestinal symptoms can adversely affect the quality of life and nutritional status. CKD is associated with structural and functional gastrointestinal changes such as intestinal barrier disruption, digestion and absorption of nutrients, motility and gut dysbiosis. Gastrointestinal disturbances are usually due to uremia or the effects of renal replacement therapy. However, sometimes primary kidney disease or drugs (phosphorus-binding agents, anticoagulants, non-steroidal anti-inflammatory drugs, etc.) may be responsible for gastrointestinal symptoms. Gastrointestinal symptoms tend to increase as the stage of kidney disease progresses. These complications of varying frequency are anorexia, nausea, vomiting, glossitis, malnutrition, halitosis, gingival hyperplasia, oral candidiasis, dyspepsia, gastroesophageal reflux and esophagitis, acute abdominal pain, peptic ulcer, gastritis and duodenitis, prolonged gastric emptying time and gastroparesis, bleeding, constipation, diarrhea, hepatitis, ascites, intestinal ischemia, diverticulitis, angiodysplasias and acute pancreatitis. The prevalence of gastrointestinal symptoms is high in dialysis patients. Each of the renal replacement therapies is associated with specific gastrointestinal problems. In peritoneal dialysis, increased intraabdominal pressure, delayed gastric emptying, and absorption of glucose content of peritoneal dialysis solutions may cause some gastrointestinal complaints in patients. The prevalence of reflux, eating disorders, gastroesophageal reflux, intestinal obstruction or adhesions, and abdominal hernia is higher in peritoneal dialysis patients compared to hemodialysis patients. Peritonitis is also common. However, encapsulated peritoneal sclerosis is a rare and severe complication of prolonged peritoneal dialysis. Kidney transplant recipients under chronic immunosuppression therapy may experience gastrointestinal complications in a broad clinical spectrum ranging from diarrhea to inflammatory bowel disease. Gut microbiota and gut dysbiosis have focused on the 'gut-kidney' and 'gut-bone-vascular' axes in patients with CKD. Gut dysbiosis in CKD may be associated with vascular calcification and bone demineralization. Results of studies examining the associations between a low-protein diet and changes in the gut microbiota suggest that treatments such as probiotics, prebiotics, and synbiotics may be beneficial in improving gastrointestinal health in this population. New preventive approaches targeting the microbiome may also improve cardiovascular and bone health in uremic patients. Thus, we can order personalized dietary recommendations for CKD patients. In conclusion, I reviewed different aspects of gastrointestinal system-related disturbances and treatment approaches in CKD in this chapter.