Abstract
BackgroundNutrition therapy is the cornerstone of treating diabetes mellitus. The inclusion of fish (particularly oily fish) at least two times per week is recommended by current international dietary guidelines for type 2 diabetes. In contrast to a large number of human studies examining the effects of oily fish on different cardiovascular risk factors, little research on this topic is available in patients with type 2 diabetes. The aims of this pilot study were to investigate the effects of a sardine-enriched diet on metabolic control, adiponectin, inflammatory markers, erythrocyte membrane fatty acid (EMFA) composition, and gut microbiota in drug-naïve patients with type 2 diabetes.Methods35 drug-naïve patients with type 2 diabetes were randomized to follow either a type 2 diabetes standard diet (control group: CG), or a standard diet enriched with 100 g of sardines 5 days a week (sardine group: SG) for 6 months. Anthropometric, dietary information, fasting glycated hemoglobin, glucose, insulin, adiponectin, inflammatory markers, EMFA and specific bacterial strains were determined before and after intervention.ResultsThere were no significant differences in glycemic control between groups at the end of the study. Both groups decreased plasma insulin (SG: −35.3 %, P = 0.01, CG: −22.6 %, P = 0.02) and homeostasis model of assessment - insulin resistance (HOMA-IR) (SG: −39.2 %, P = 0.007, CG: −21.8 %, P = 0.04) at 6-months from baseline. However only SG increased adiponectin in plasma compared to baseline level (+40.7 %, P = 0.04). The omega-3 index increased 2.6 % in the SG compared to 0.6 % in the CG (P = 0.001). Both dietary interventions decreased phylum Firmicutes (SG and CG: P = 0.04) and increased E. coli concentrations (SG: P = 0.01, CG: P = 0.03) at the end of the study from baseline, whereas SG decreased Firmicutes/Bacteroidetes ratio (P = 0.04) and increased Bacteroides-Prevotella (P = 0.004) compared to baseline.ConclusionsAlthough enriching diet with 100 g of sardines 5 days a week during 6 months to a type 2 diabetes standard diet seems to have neutral effects on glycemic control in drug-naïve patients with type 2 diabetes, this nutritional intervention could have beneficial effects on cardiovascular risk. Furthermore, both dietary interventions decreased HOMA-IR and altered gut microbiota composition of drug-naïve patients with type 2 diabetes.Trial registrationTrial number and name of the registry: NCT02294526, ClinicalTrials.govElectronic supplementary materialThe online version of this article (doi:10.1186/s12944-016-0245-0) contains supplementary material, which is available to authorized users.
Highlights
IntroductionNutrition therapy is the cornerstone of treating diabetes mellitus. The inclusion of fish ( oily fish) at least two times per week is recommended by current international dietary guidelines for type 2 diabetes
Nutrition therapy is the cornerstone of treating diabetes mellitus [2], and current international dietary guidelines recommend the inclusion of fish at least two times per week for subjects with Type 2 diabetes (T2D) [2, 3]
The omega-3 index (O3I) is the eicosapentanoic acid (EPA) + docosahexanoic acid (DHA) content in erythrocytes expressed as a percentage of total identified fatty acids
Summary
Nutrition therapy is the cornerstone of treating diabetes mellitus. The inclusion of fish ( oily fish) at least two times per week is recommended by current international dietary guidelines for type 2 diabetes. The fact that supplements of seafood-derived n-3 (omega 3) failed to improve insulin metabolism in patients with T2D [5] prompted the hypothesis that nutrients other than omega-3 fatty acids may contribute to the beneficial effects of fish in T2D These nutrients include fish protein and specific amino acids, taurine, an essential amino acid which can be found abundantly in sardines (Sardina pilchardus) [6]. In this regard, rats with diabetes and metabolic syndrome improved insulin resistance, inflammatory status and hyperglycemia after a diet supplemented with proteins obtained from sardines [6, 7]. This overall makes sardine consumption an appealing strategy to limit the complications of T2D
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call