**4.4 Synbiotics**

Synbiotics are substances that contain a mixture of probiotics and prebiotics, with the intention of improving the activity and survival of bacteria in the intestine. Several studies in patients with stage 3 to 5 chronic kidney disease have evaluated some synbiotic-type products, managing to find a decrease in the values of uremic toxins in the blood. Reports of some laxatives agents [44] and oral activated charcoal adsorbent AST-120 [45] have suggested to reduce concentrations of some uremic toxins, but the effect wanes after stopping its use. Some studies in animals with chronic kidney disease have evaluated the use of sodium-glucose cotransporter (SGLT) 2 inhibitor Canagliflozin. This drug also has an inhibitory effect on SGLT 1, which has a gastrointestinal effect by promoting intestinal fermentation of carbohydrates and reducing plasma levels of p-cresyl and indoles [46, 47].
