Effect of Cucumis melo L. peel extract supplemented postbiotics on reprograming gut microbiota and sarcopenia in hindlimb-immobilized mice.

Postbiotics made from lactic acid bacteria may ameliorate sarcopenia via the metabolic reprogramming of gut dysbiosis. This study investigated the anti-sarcopenic effect of postbiotics (WDK) produced from polyphenol-rich melon peel extract (Cucumis melo L. var. makuwa, KEE) and whey with Lentilactobacillus kefiri DH5 (DH5) in C2C12 skeletal muscle cells and hindlimb-immobilized mice. WDK significantly ameliorated palmitate-induced atrophy of C2C12 cells, restoring myotube length and diameter. It also upregulated the expression of myogenic genes including Atrogin-1, Igf-1, and MyoD. Hindlimb-immobilized C57BL/6J mice were randomly divided and orally administered 10 mL/kg body weight of saline (CON), Whey, Whey + DH5 (WD), DH5 + KEE, Whey + DH5 + KEE postbiotic (WDK) for three weeks (n = 10/group). Interestingly, WDK significantly improved muscle function in hindlimb-immobilized mice by restoring both the grip strength and the mass of the soleus muscle, which was closely related to the upregulation of the myoD gene. WDK increased microbial diversity and modulated the distribution of intestinal bacteria, particularly those involved in protein synthesis and the production of butyrate. There was a significant correlation between myogenic biomarkers and butyrate producing gut microbiota. Restoration of muscle mass and function following postbiotic WDK is strongly related to the regulation of myogenic genes by in part remodulating gut microbiota. In conclusion, these findings suggest that polyphenol- and whey-based postbiotics WDK may have potential as an effective manner to combat the progression of sarcopenia.

Effects of kefir lactic acid bacteria-derived postbiotic components on high fat diet-induced gut microbiota and obesity.

Cellular components, surface layer protein (SLP) and exopolysaccharides (EPS) of postbiotic lactic bacteria (PLAB) can rehabilitate high-fat diet-induced dysbiosis and obese characteristic gut microbiome. However, it is not clear whether and how PLAB components affect gut microbiota and specifically adipocyte gene expression. Furthermore, SLP and EPS of PLAB in combination with polyphenolics of prebiotic wine grape seed flour (GSF) may have greater benefit on high-fat diet (HFD)-induced obesity and gut microbiota imbalance. To investigate interactions, C57BL/6 mice were fed a HFD and orally administered saline (CON), 250 mg/Kg EPS, or 120 mg/Kg SLP or saline with fed 2% GSF (GSF) or combination (42 mg/Kg EPS + 20 mg/Kg SLP + 0.5% GSF; ALL). There were significant reductions of HFD-induced body weight gain, adipose weight, serum triglyceride, and insulin resistance by the SLP and ALL diets compared to CON, with the most profound effect by ALL. ALL significantly affected the distribution of intestinal bacterial genus and species particularly those involved in production of short chain fatty acid (SCFA) and anti-obesogenic action. Microarray analysis from adipose tissue showed that ALL significantly affected expression of genes related to fatty acid biosynthesis, autophagy, inflammatory response, immune response, brown adipose tissue development and response to lipoteichoic acid and peptidoglycan (p < 0.05). Interestingly, expression of Akp13 (A-kinase anchoring protein 13) gene, which is related to body mass index and immune response, was negatively associated with the abundance of obesogenic and SCFAs producing gut bacteria. These data suggest that a combination of postbiotic kefir LAB cellular components and prebiotic GSF establishes a healthy intestinal microbiota that in part was associated with the prevention of obesity and obesity-related diseases.

(1-3)(1-6)-ß-glucan-enriched materials from Lentinus edodes mushroom as a high-fibre and low-calorie flour substitute for baked foods.

BACKGROUND: Extensive physiological and biological emphasis has been placed on pharmaceutical and medicinal uses of mushrooms containing ß-glucans, but their incorporation into processed functional foods is quite limited. Thus, low-grade Lentinus edodes mushrooms were utilised to produce ß-glucan-enriched materials (BGEMs), which were evaluated as a high-fibre and low-calorie substitute for wheat flour. RESULTS: The fractions obtained from Lentinus edodes mushrooms contained 514 g kg⁻¹ of (1-3)-ß-glucans with (1-6)-ß-linked side chains and the chemical structure was confirmed by ¹³C NMR and FTIR spectroscopy. Replacement of a portion of the wheat flour with BGEMs resulted in the solutions with lower values of pasting parameters and also caused significant changes in starch gelatinisation. When BGEMs were incorporated into cake formulations, batter viscosity increased with more shear-thinning behaviours and elastic properties improved. Overall, the cakes containing more BGEMs showed decreased volume and increased hardness while no significant differences were observed between the control and BGEM cakes containing 1 g of ß-glucan per serving. CONCLUSION: As a wheat flour substitute, the BGEMs that were prepared from low-grade Lentinus edodes mushrooms, could be successfully used to produce cakes containing 1 g of ß-glucan per serving with quality attributes similar to those of the control.

Effect of levan's branching structure on antitumor activity.

Levan produced from Microbacterium laevaniformans KCTC 9732 (M-levan) was isolated and treated with an inulinase to modify its branching structure. The chemical structures of levans were characterized, and the modified levans were applied on animal tumor cells to evaluate their antitumor activity. The GC-MS analysis indicated that beta-(2,1)-linked branches of M-levan were specifically hydrolyzed. As the ratio of applied inulinase to levan increased, the branching degree decreased proportionally. Sequential degrees of branching were obtained from 12.3 to 4.2%. Strong levan-induced inhibition of cell growth was detected on SNU-1 and HepG2 tumor cell lines. As the branching degree of M-levan reduced, antitumor activity on SNU-1 linearly decreased (r2=0.96). In HepG2, the antitumor activity rapidly dropped when the branching reached up to 9.3%, then slightly increased as the branching degree of M-levan further decreased. These results suggested that the branch structure would play a crucial role in levan's antitumor activity.