McFarlane, C., Ramos, C. I., Johnson, D. W. & Campbell, K. L. Prebiotic, probiotic, and synbiotic supplementation in chronic kidney disease: a systematic review and meta-analysis. J. Ren. Nutr. 29, 209–220 (2019). Mahboobi, S., Rahimi, F. & Jafarnejad, S. Effects of prebiotic and synbiotic supplementation on glycaemia and lipid profile in type 2 diabetes: a meta-analysis of randomized controlled trials. Adv. Pharm. Bull. 8, 565–574 (2018). Childs, C. E. et al. Xylo-oligosaccharides alone or in synbiotic combination with Bifidobacterium animalis subsp. lactis induce bifidogenesis and modulate markers of immune function in healthy adults: a double-blind, placebo-controlled, randomised, factorial cross-over study. Br. J. Nutr. 111, 1945–1956 (2014). Meance, S. et al. Recent advances in the use of functional foods: effects of the commercial fermented milk with Bifidobacterium animalis strain DN-173 010 and yoghurt strains on gut transit time in the elderly. Microb. Ecol. Health Dis. 15, 15–22 (2003).

Malaguarnera, M. et al. Bifidobacterium longum with fructo-oligosaccharides in patients with non alcoholic steatohepatitis. Dig. Dis. Sci. 57, 545–553 (2012). Faculty of Kinesiology and Department of Biochemistry and Mol Does treatment of dysbiosis improve outcomes in cancer patients and in patients with other diseases? Earle, K. A. et al. Quantitative imaging of gut microbiota spatial organization. Cell Host Microbe 18, 478–488 (2015).

Whittemore, J.C., Moyers, T.D., Price, J.M., 2019. Randomized, controlled, crossover trial of prevention of antibiotic‐induced gastrointestinal signs using a synbiotic mixture in healthy research dogs. Journal of Veterinary Internal Medicine.. doi:10.1111/jvim.15553 Rossi G, Pengo G, Caldin M, et al. Comparison of microbiological, histological, and immunomodulatory parameters in response to treatment with either combination therapy with prednisone and metronidazole or probiotic VSL#3 strains in dogs with idiopathic inflammatory bowel disease. PLoS One 2014;9(4):e94699.

Klurfeld, D. M. et al. Considerations for best practices in studies of fiber or other dietary components and the intestinal microbiome. Am. J. Physiol. Endocrinol. Metab. 315, E1087–E1097 (2018).

As with probiotics, the desired outcome after giving prebiotics is improvement of host health. 21 However, the specific aim of giving prebiotics is to promote growth and function of the beneficial bacteria already present in the gut. Intake of prebiotics can significantly modulate the colonic microbiota by increasing the number of specific bacteria and thus changing the composition of the microbiota. 23 Prebiotics are metabolized by the resident microbiota of the colon, which, depending on fermentability, will result in the production of the short-chain fatty acids butyrate, propionate, and acetate. 23 These metabolites will diffuse through gut enterocytes and provide either local effects (e.g., enhance the intestinal epithelial barrier, decrease pro-inflammatory cytokines, regulate intestinal motility) or systemic effects (e.g., provide energy for the host). 24,25 Apart from direct prebiotic effects, dietary fibers can have additional functions in the GI tract. Psyllium, for example, has water-binding and bile acid–binding properties that improve fecal consistency, increase the intestinal mucus layer, and have beneficial effects on cell proliferation in the intestinal tract. 26 Synbiotics