Postprandial Effects of Salmon Fishmeal and Whey on Metabolic Markers in Serum and Gene Expression in Liver Cells

A randomized controlled cross-over trial investigating the acute inflammatory and metabolic response after meals based on red meat, fatty fish, or soy protein: the postprandial inflammation in rheumatoid arthritis (PIRA) trial

PURPOSE

Rheumatoid Arthritis (RA) has a point prevalence of around 20 million people worldwide. Patients with RA often believe that food intake affects disease activity, and that intake of red meat aggravate symptoms. The main objective of the Postprandial Inflammation in Rheumatoid Arthritis (PIRA) trial was to assess whether postprandial inflammation and serum lipid profile are affected differently by a meal including red meat, fatty fish, or a soy protein (vegan) meal.

METHODS

Using a randomized controlled crossover design, 25 patients were assigned to eat isocaloric hamburger meals consisting of red meat (60% beef, 40% pork), fatty fish (salmon), or soy protein for breakfast. Blood samples were taken before meals and at intervals up to 5 h postprandial. The analysis included the inflammation marker interleukin 6 (IL-6) and serum lipids.

RESULTS

No significant differences in postprandial IL-6 or triglyceride concentrations were found between meals. However, the area under the curve of very low density lipoprotein (VLDL) particle counts, as well as VLDL-4-bound cholesterol, triglycerides, and phospholipids, was higher after the fatty fish compared to both red meat and soy protein.

CONCLUSION

Postprandial inflammation assessed by IL-6 did not indicate any acute negative effects of red meat intake compared to fatty fish- or soy protein in patients with RA. The fatty fish meal resulted in a higher number of VLDL-particles and more lipids in the form of small VLDL particles compared to the other protein sources.

The Gut Microbiota of Farmed and Wild Brook Trout (Salvelinus fontinalis): Evaluation of Feed-Related Differences Using 16S rRNA Gene Metabarcoding

The gut microbiota has become a topic of increasing importance in various fields, including aquaculture. Several fish species have been the subject of investigations concerning the intestinal microbiota, which have compared different variables, including the intestinal portions, the environment, and diet. In this study, the microbiota of farmed and wild brook trout (Salvelinus fontinalis) were analyzed, in which the wall and content of the medial portion of the intestine were considered separately. A total of 66 fish (age class 2+) were sampled, of which 46 were wild and 20 were farmed brook trout, in two different years. Microbiota data were obtained using a 16S metabarcoding approach by analyzing the V3-V4 hypervariable regions of the corresponding 16S rRNA. The data showed that the core microbiota of these species consist of Proteobacteria (Alpha- and Gammaproteobacteria), Actinobacteria, Firmicutes (Bacilli and Clostridia), and, only for farmed animals, Fusobacteria. The latter taxon's presence is likely related to the fishmeal-based diet administered to farmed brook trout. Indeed, alpha and beta diversity analysis showed differences between wild and farmed fish. Finally, statistically significant differences in the microbiota composition were observed between the intestinal walls and contents of wild fish, while no differences were detected in reared animals. Our work represents the first study on the intestinal microbiota of brook trout with respect to both farmed and wild specimens. Future studies might focus on the comparison of our data with those pertaining to other fish species and on the study of other portions of the brook trout intestine.

Glycated Proteins, Glycine, Acetate, and Monounsaturated Fatty Acids May Act as New Biomarkers to Predict the Progression of Type 2 Diabetes: Secondary Analyses of a Randomized Controlled Trial

Food protein or food-derived peptides may regulate blood glucose levels; however, studies have shown inconsistent results. The aim of the present study was to characterize subgroups of individuals with increased risk of type 2 diabetes (T2D) and to investigate the cardiometabolic effects of fish protein in the same subgroups. We first divided participants into high insulin_iAUC and low insulin_iAUC subjects based on their insulin incremental area under the curve (iAUC) levels after a 2 h oral glucose tolerance test (OGTT), and secondly based on whether they had received 5.2 g salmon fish protein or placebo for 8 weeks, in a previously conducted randomized controlled trial (RCT). We then profiled these groups by analyzing plasma metabolomics and peripheral blood mononuclear cell (PBMC) gene expression. Compared to the low insulin_iAUC group, the high insulin_iAUC group had higher plasma concentrations of monounsaturated fatty acids (MUFAs) and glycated proteins (GlycA) and lower concentrations of glycine and acetate. After intervention with fish protein compared to placebo, however, only acetate was significantly increased in the low insulin_iAUC group. In conclusion, we identified metabolic biomarkers known to be associated with T2D; also, intervention with fish protein did not affect cardiometabolic risk markers in subgroups with increased risk of T2D.