Polysaccharides and Plant Cell Walls (45)Polysaccharides Composition and Applications (20)Ginseng Biological Effects and Applications (18)Microbial Metabolites in Food Biotechnology (16)Fungal Biology and Applications (13)
Raffinose family oligosaccharides (RFOs) have diverse structures and exhibit various biological activities. When using RFOs as prebiotics, their structures need to be identified. If we first knew whether an RFO was classical or non-classical, structural identification would become much easier. Here, we cloned and expressed an α-galactosidase (BF0224) from Bacteroides fragilis which showed strict specificity for hydrolyzing α-Gal-(1 → 6)-Gal linkages in RFOs. BF0224 efficiently distinguished classical from non-classical RFOs by identifying the resulting hydrolyzed oligo- and mono-saccharides with HPAEC-PAD-MS. Using this strategy, we identified a non-classical RFO from Pseudostellaria heterophylla (Miquel) Pax with DP6 (termed PHO-6), as well as a classical RFO from Lycopus lucidus Turcz. with DP7 (termed LTO-7). To characterize these RFO structures, we employed four other commercial or reported α-galactosidases in combination with NMR and methylation analysis. Using this approach, we elucidated the accurate chemical structure of PHO-6 and LTO-7. Our study provides an efficient analytical approach to structurally analyze RFOs. This enzyme-based strategy also can be applied to structural analysis of other glycans.
The study (PROSPERO: CRD42021240905) aims to reveal the relationships among red meat, serum lipids and inflammatory biomarkers. PubMed, EMBASE and the Cochrane databases were explored through December 2021 to identify 574 studies about red meat and serum lipids markers including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), C-reactive protein (CRP) or hypersensitive-CRP (hs-CRP). Finally, 20 randomized controlled trials (RCTs) involving 1001 people were included, red meat and serum lipid markers and their relevant information was extracted. The pooled standard mean difference (SMD) was obtained by applying a random-effects model, and subgroup analyses and meta-regression were employed to explain the heterogeneity. Compared with white meat or grain diets, the gross results showed that the consumption of red meat increased serum lipid concentrations like TG (0.29 mmol/L, 95% CI 0.14, 0.44,<0.001), but did not significantly influence the TC (0.13 mmol/L, 95% CI -0.07, 0.33, = 0.21), LDL-C (0.11 mmol/L, 95% CI -0.23, 0.45, = 0.53), HDL-C (-0.07 mmol/L, 95% CI -0.31, 0.17, = 0.57),CRP or hs-CRP (0.13 mmol/L, 95% CI -0.10, 0.37, = 0.273). Our study provided evidence to the fact that red meat consumption affected serum lipids levels like TG, but almost had no effect on TC, LDL-C, HDL-C and CRP or hs-CRP. Such diets with red meat should be taken seriously to avoid the problem of high lipid profiles. [https://www.crd.york.ac.uk/PROSPERO], identifier [CRD42021240905].