Background: Complex relationships exist between the gut microflora and their human hosts. Emerging evidence suggests that bacterial dysbiosis within the colon may be implicated in the pathogenesis of the metabolic syndrome, type 2 diabetes and cardiovascular disease. The use of prebiotic dietary supplements to restore an optimal balance of intestinal flora may positively impact host metabolism, representing a potential treatment strategy for individuals with cardiometabolic disorders.
Aim: This review aimed to examine the current evidence supporting the benefits of dietary prebiotic supplementation in adults on biochemical parameters associated with the development of metabolic abnormalities including obesity, glucose intolerance, dyslipidaemia, hepatic steatosis and low-grade chronic inflammation.
Method: Eight computer databases were searched for randomised controlled trials (RCTs) published in English between January 2000 and January 2013. Human trials were included if at least one group received a prebiotic dietary intervention. Twenty-six RCTs involving 831 participants were included in the review.
Results: Evidence indicated that dietary prebiotic supplementation increased self-reported feelings of satiety in healthy adults (Standardised Mean Difference -0.57; 95%CI:-1.13,-0.01). Prebiotic supplementation also significantly reduced post-prandial glucose (SMD -0.76; 95%CI:-1.41,-0.12) and insulin (SMD -0.77; 95%CI:-1.50,-0.04) concentrations. The effects of dietary prebiotics on total energy intake, body weight, peptide YY and GLP-1 concentrations, gastric emptying times, insulin sensitivity, lipids, inflammatory markers and immune function were contradictory.
Conclusion: Dietary prebiotic consumption is associated with subjective improvements in satiety and reductions in postprandial glucose and insulin levels. Additional evidence is required before recommending prebiotic supplements to individuals with metabolic abnormalities. Large-scale trials of longer duration, which evaluate gut microbial growth and activity are required. (Kellow et al., Br J Nutr 2014; 111: 1147-1161).