Scientists from the Federal University of Santa Catarina in Brazil reported that prebiotics were associated with significant reductions in total and LDL cholesterol, and triglyceride levels, while synbiotic supplements were associated with improvements in insulin and triglyceride levels.
“To our knowledge, the present meta-analysis is the first that included trials performed only with overweight or obese individuals,” they wrote in Clinical Nutrition.
“Thus, the supplementation of prebiotics or synbiotics could take part in the management of obesity-related comorbidities, such as dyslipidemia and insulin resistance.”
Prebiotics are defined as "non-digestible substances that provide a beneficial physiological effect on the host by selectively stimulating the favorable growth or activity of a limited number of indigenous bacteria". According the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host". Synbiotics are a combination of the two.
For the new meta-analysis, the Brazil-based scientists identified 13 trials with data for 513 overweight and obese adults (9 trials for prebiotics and 4 trials for synbiotics). The prebiotic trials included a variety of ingredients, such as inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS), while the synbiotic trials used inulin or FOS with a combination of Lactobacillus and Bifidobacteria.
Results showed that the prebiotics were associated with reductions in total and LDL-cholesterol. In addition, there were improvements in triglyceride and HDL-cholesterol levels in diabetic trials, they said.
On the other hand, synbiotic supplementation was only associated with lower fasting insulin levels and decreased triglyceride concentrations.
“Despite the lack of studies to establish a dosage range and duration of supplementation to achieve positive effects, the benefits of these supplements shown by pooled analysis makes the intestinal microbiota another therapeutic target in management of various diseases and at the maintenance and promotion of health,” they wrote.
The researchers also addressed the issue of potential side effects from consuming short-chain carbohydrates and sugar alcohols called FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols), which have been linked to abdominal symptoms such as bloating, pain and nausea.
“Among the carbohydrates belonging to this group, there are fructans and galactans, prebiotics used by the studies included in this meta-analysis. However, the studies that reported the presence of adverse effects also noted improvement in symptoms during the supplementation, without the withdrawal of participants, allowing us to believe that there is an adaptation period.
“Although it is not yet clear what the long-term effects of fructans and galactans, the consumption of these food ingredients by individuals with excess weight seems to be a good strategy in the improvement of the evaluated parameters in this meta-analysis.”
Source: Clinical Nutrition
Published online ahead of print, doi: 10.1016/j.clnu.2014.10.004
“A Systematic Review and Meta-Analysis of the prebiotics and synbiotics effects on glycaemia, insulin concentrations and lipid parameters in adult patients with overweight or obesity”
Authors: B.T.S. Beserra, R. Fernandes, V.A. do Rosario, et al.