Biosynthesis of Nondigestible Galactose-Containing Hetero-oligosaccharides by Lactobacillus plantarum WCFS1 MelA α-Galactosidase

Correlations between the structure and anti-diabetic activity of novel polysaccharides from raw and "Nine Steaming Nine Sun-Drying" Polygonti rhizome

"Nine Steaming Nine Sun-Drying" Polygonti rhizome has been used as valuable tonic health-care products for thousands of years. This research aimed to determine the correlations between the structure and anti-diabetic activities of three novel polysaccharides isolated from the raw and "Nine Steaming Nine Sun-Drying" Polygonti rhizome, with PRP-R from the raw ones and PRP-9Z and PRP-9A from the steamed ones. Structures of the isolated polysaccharides were determined by IR and NMR spectra, as well as monosaccharide composition and methylation analysis. In vitro assays indicated that PRP-9Z could improve the glucose consumptions more effectively than PRP-R and PRP-9A via Akt/GSK3β insulin signal pathway by western blotting analysis. In vivo assays indicated PRP-9Z could improve the glucose tolerance in the BKS-db mice. Histopathological assay demonstrated that PRP-9Z effectively reduced the damage of the kidney and liver. The above results indicated that PRP-9Z from "Nine Steaming Nine Sun-Drying" Polygonti rhizome showed significant anti-diabetic properties, which indicated that PRP-9Z with higher content of →1)-β-Frup-(2→ was more active than PRP-R with higher →1,6)-β-Fruf-(2→ and PRP-9A with higher →4)-β-Galp(1→.

Food phenolics and Lactiplantibacillus plantarum

Phenolic compounds are important constituents of plant food products. These compounds play a key role in food characteristics such as flavor, astringency and color. Lactic acid bacteria are naturally found in raw vegetables, being Lactiplantibacillus plantarum the most commonly used commercial starter for the fermentation of plant foods. Hence, the metabolism of phenolic compounds of L. plantarum has been a subject of study in recent decades. Such studies confirm that L. plantarum, in addition to presenting catalytic capacity to transform aromatic alcohols and phenolic glycosides, exhibits two main differentiated metabolic routes that allow the biotransformation of dietary hydroxybenzoic and hydroxycinnamic acid-derived compounds. These metabolic pathways lead to the production of new compounds with new biological and organoleptic properties. The described metabolic pathways involve the action of specialized esterases, decarboxylases and reductases that have been identified through genetic analysis and biochemically characterized. The purpose of this review is to provide a comprehensive and up-to-date summary of the current knowledge of the metabolism of food phenolics in L. plantarum.

The promotion mechanism of prebiotics for probiotics: A review

Prebiotics and probiotics play a positive role in promoting human nutrition and health. Prebiotics are compounds that cannot be digested by the host, but can be used and fermented by probiotics, so as to promote the reproduction and metabolism of intestinal probiotics for the health of body. It has been confirmed that probiotics have clinical or health care functions in preventing or controlling intestinal, respiratory, and urogenital infections, allergic reaction, inflammatory bowel disease, irritable bowel syndrome and other aspects. However, there are few systematic summaries of these types, mechanisms of action and the promotion relationship between prebiotics and probiotic. Therefore, we summarized the various types of prebiotics and probiotics, their individual action mechanisms, and the mechanism of prebiotics promoting probiotics in the intestinal tract. It is hoped this review can provide new ideas for the application of prebiotics and probiotics in the future.

Prebiotic Potential of a New Sweetener Based on Galactooligosaccharides and Modified Mogrosides

This study was conducted to investigate the sweetness intensity and the potential fecal microbiome modulation of galactooligosaccharides in combination with enzymatically modified mogrosides (mMV-GOS), both generated through a patented single-pot synthesis. Sweetness intensity was performed in vivo by trained sensory panelists. The impact on the human fecal microbiome was evaluated by in vitro pH-controlled batch fermentation, and bacterial populations and organic acid concentrations were measured by qPCR and GC-FID, respectively. Significant growth (p ≤ 0.05) during the fermentation at 10 h of bacterial populations includes Bifidobacterium (8.49 ± 0.44 CFU/mL), Bacteroides (9.73 ± 0.32 CFU/mL), Enterococcus (8.17 ± 0.42 CFU/mL), and Clostridium coccoides (6.15 ± 0.11 CFU/mL) as compared to the negative control counts for each bacterial group (7.94 ± 0.27, 7.84 ± 1.11, 7.52 ± 0.37, and 5.81 ± 0.08 CFU/mL, respectively) at the same time of fermentation. Likewise, the corresponding significant increase in production of SCFA in mMV-GOS at 10 h of fermentation, mainly seen in acetate (20.32 ± 2.56 mM) and propionate (9.49 ± 1.44 mM) production compared to a negative control at the same time (8.15 ± 1.97 and 1.86 ± 0.24 mM), is in line with a positive control (short-chain fructooligosaccharides; 46.74 ± 12.13 and 6.51 ± 1.91 mM, respectively) revealing a selective fermentation. In conclusion, these substrates could be considered as novel candidate prebiotic sweeteners, foreseeing a feasible and innovative approach targeting the sucrose content reduction in food. This new ingredient could provide health benefits when evaluated in human studies by combining sweetness and prebiotic fiber functionality.

Production and Digestibility Studies of β-Galactosyl Xylitol Derivatives Using Heterogeneous Catalysts of LacA β-Galactosidase from Lactobacillus Plantarum WCFS1

The synthesis of β-galactosyl xylitol derivatives using immobilized LacA β-galactosidase from Lactobacillus plantarum WCFS1 is presented. These compounds have the potential to replace traditional sugars by their properties as sweetener and taking the advantages of a low digestibility. The enzyme was immobilized on different supports, obtaining immobilized preparations with different activity and stability. The immobilization on agarose-IDA-Zn-CHO in the presence of galactose allowed for the conserving of 78% of the offered activity. This preparation was 3.8 times more stable than soluble. Since the enzyme has polyhistidine tags, this support allowed the immobilization, purification and stabilization in one step. The immobilized preparation was used in synthesis obtaining two main products and a total of around 68 g/L of β-galactosyl xylitol derivatives and improving the synthesis/hydrolysis ratio by around 30% compared to that of the soluble enzyme. The catalyst was recycled 10 times, preserving an activity higher than 50%. The in vitro intestinal digestibility of the main β-galactosyl xylitol derivatives was lower than that of lactose, being around 6 and 15% for the galacto-xylitol derivatives compared to 55% of lactose after 120 min of digestion. The optimal amount immobilized constitutes a very useful tool to synthetize β-galactosyl xylitol derivatives since it can be used as a catalyst with high yield and being recycled for at least 10 more cycles.