Polysaccharides from Bamboo Shoot (Leleba oldhami Nakal) Byproducts Alleviate Antibiotic-Associated Diarrhea in Mice through Their Interactions with Gut Microbiota.

A water-soluble polysaccharide BSP was extracted from the basal part of bamboo shoot, a main by-product of bamboo shoot processing. BSP is composed of glucose (72.8%), xylose (19.43%) and a small amount of galactose, arabinose, glucuronic acid and mannose. The effects of BSP on mice with antibiotic-associated diarrhea (AAD) were investigated. The mice fed with BSP exhibited significant higher bodyweight gain, lower pH value and higher concentrations of SCFAs in the feces compared with those fed with saline. BSP administration reduced the inflammatory cells in the small intestine and colon in the AAD mice, and Firmicutes/Bacteroidetes ratio in the gut was decreased from 0.56 to 0.19. Moreover, BSP administration affected the composition and diversity of the gut microbiota in the AAD mice, particularly on the improvement of beneficial bacteria such as Bacteroides, Lactobacillus and Lachnospiraceae_NK4A136_group. Our results suggest that the polysaccharides from bamboo shoot by-products could be an attractive natural component for gut health and AAD treatment.

The Single-Stranded DNA-Binding Gene Whirly (Why1) with a Strong Pathogen-Induced Promoter from Vitis pseudoreticulata Enhances Resistance to Phytophthora capsici.

Vitis vinifera plants are disease-susceptible while Vitis pseudoreticulata plants are disease-resistant; however, the molecular mechanism remains unclear. In this study, the single-stranded DNA- and RNA-binding protein gene Whirly (VvWhy1 and VpWhy1) were cloned from V. vinifera "Cabernet Sauvignon" and V. pseudoreticulata "HD1". VvWhy1 and VpWhy1 promoter sequences (pVv and pVp) were also isolated; however, the identity of the promoter sequences was far lower than that between the Why1 coding sequences (CDSs). Both Why1 gene sequences had seven exons and six introns, and they had a C-terminal Whirly conserved domain and N-terminal chloroplast transit peptide, which was then verified to be chloroplast localization. Transcriptional expression showed that VpWhy1 was strongly induced by Plasmopara viticola, while VvWhy1 showed a low expression level. Further, the GUS activity indicated pVp had high activity involved in response to Phytophthora capsici infection. In addition, Nicotiana benthamiana transiently expressing pVp::VvWhy1 and pVp::VpWhy1 enhanced the P. capsici resistance. Moreover, Why1, PR1 and PR10 were upregulated in pVp transgenic N. benthamiana leaves. This research presented a novel insight into disease resistance mechanism that pVp promoted the transcription of Why1, which subsequently regulated the expression of PR1 and PR10, further enhancing the resistance to P. capsici.

Structural characterization of a soluble polysaccharide SSPS1 from soy whey and its immunoregulatory activity in macrophages.

A soluble soybean polysaccharide SSPS1 with a molecular weight of 2737 kDa was extracted and purified from soy whey. SSPS1 was composed of glucose (97.3 %) and a small amount of mannose (2.7 %). Structural analysis results suggested that SSPS1 had a â†’ 6)-α-d-Glcp-(1 â†’ glucan structure, with a trace amount of α-d-Glcp-(1 â†’ connected to the main chain via O-3. In vitro immunological experiments suggested that SSPS1 enhanced the growth rate and phagocytic activity of RAW 264.7 macrophages. In addition, SSPS1 stimulated the secretion of cytokines (TNF-α, INF-ß, IL-6 and IL-1ß) as well as nitric oxide (NO) production through upregulating the expression of the related genes and proteins in RAW 264.7 cells. This study provided a new method for efficient utilization of soy whey, and the results indicate that SSPS1 extracted from soy whey could be used as a novel immunomodulator.

Selenium enrichment improves anti-proliferative effect of oolong tea extract on human hepatoma HuH-7 cells.

Selenium (Se)-enriched tea is attracting increasing interests due to its significantly improved health benefits. This study was to investigate the anti-proliferative effects of Se-enriched oolong tea against human hepatoma HuH-7 cells. Compared with regular oolong tea extract (TE, 0.04 µg selenium/g), Se-enriched oolong tea extract (Se-TE, 0.51 µg selenium/g) exhibited more prominent anti-proliferative effect against HuH-7 cells with an IC50 of 203.1 µg/mL, mainly due to the synergistic effects of organic selenium and tea polyphenols. Our results found that Se-TE increased intracellular ROS production, arrested the cell cycle at G2/M phase, and thus induced cell apoptosis. In addition, western blotting assay revealed the increased expressions of the p53, Bax, caspase 3, and a reduction of Bcl-2 and CDK2, resulting in Se-TE-induced apoptosis. The improved anti-proliferative effect makes Se-enriched oolong tea extract a promising health-promoting ingredient in food industry.

Pediococcus pentosaceus B49 from human colostrum ameliorates constipation in mice.

Constipation is a prevalent and burdensome gastrointestinal (GI) disorder that seriously affects the quality of human life. This study evaluated the effects of the P. pentosaceus B49 (from human colostrum) on loperamide (Lop)-induced constipation in mice. Mice were given P. pentosaceus B49 (5 × 109 CFU or 5 × 1010 CFU) by gavage daily for 14 days. The result shows that P. pentosaceus B49 treatment relieved constipation in mice by shortening the defecation time, increasing the GI transit rate and stool production. Compared with the constipation control group, the P. pentosaceus B49-treated groups showed decreased serum levels of inhibitory neurotransmitters (vasoactive intestinal peptide and nitric oxide), increased serum levels of excitatory neurotransmitters (acetylcholinesterase, motilin, and gastrin), and elevated cecal concentration of short chain fatty acids (SCFAs). Analysis of cecal microbiota reveals that P. pentosaceus B49 was colonized in the intestine of constipated mice, and altered the cecal microbiota by increasing beneficial SCFAs-producing bacteria (i.e., Lactobacillus, Ruminococcaceae_UCG-014, and Bacteroidales_S24-7) and decreasing potential pathogenic bacteria (i.e., Staphylococcus and Helicobacter). Moreover, transcriptome analysis of the colon tissue shows that P. pentosaceus B49 partly normalized the expression of genes related to GI peristalsis (i.e., Ache, Chrm2, Slc18a3, Grp, and Vip), water and electrolyte absorption and transport (i.e., Aqp4, Aqp8, and Atp12a), while down-regulating the expression of pro-inflammatory and pro-oncogenic genes (i.e., Lbp, Lgals2, Bcl2, Bcl2l15, Gsdmc2, and Olfm4) in constipated mice. Our findings indicate that P. pentosaceus B49 effectively relieves constipation in mice and is a promising candidate for treating constipation.

In vitro fermentation of O­acetyl­arabinoxylan from bamboo shavings by human colonic microbiota.

BSH-1 is an O­acetyl-arabinoxylan obtained from bamboo shavings. This study investigated its fermentation behavior by human colonic microbiota in vitro. Results showed that BSH-1 remarkably modulated the composition of human colonic microbiota, mainly by increasing the growth of potential beneficial genera (i.e. Bifidobacterium, Lactobacillus, Bacteroides, Prevotella_7, Parabacteroides) and by decreasing the growth of potential harmful genera (i.e. Fusobacterium, Lachnospiraceae_UCG-008, Bilophila and Desulfovibrio). BSH-1 significantly promoted the production of short-chain fatty acids, especially acetic, propionic and n-butyric acids. After 48 h fermentation, the concentration of n-butyric acid in BSH-1 fermentation culture was increased by 2.41 times compared to the blank. During fermentation, the activity of acetyl xylan esterase, arabinofuranosidase, xylanase and xylosidase was enhanced. Moreover, free arabinose, xylose, xylobiose, xylotriose, xylotetraose, xylopentaose and xylohexaose were detected. These results suggest that BSH-1 could potentially be a functional ingredient to improve gut health.

Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels

ABSTRACT Objective To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. Methods The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. Results The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940) and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v) in simulated gastric juice (pH 2.5) for 2 h and in simulated intestinal fluid (pH 8.0) for 3 h. The auto-aggregation rate increased to 87.74% after 24 h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. Conclusion These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels.

OBJECTIVE: To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. METHODS: The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. RESULTS: The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940) and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v) in simulated gastric juice (pH 2.5) for 2h and in simulated intestinal fluid (pH 8.0) for 3h. The auto-aggregation rate increased to 87.74% after 24h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. CONCLUSION: These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

Expression, purification and molecular characterization of a novel endoglucanase protein from Bacillus subtilis SB13.

Bacillus subtilis strain SB13 which is isolated in our previous work was confirmed to produce endoglucanase. In this study, a novel endoglucanase gene (accession number: KX576676) was identified and cloned from SB13. Compared with other consensus sequence of reported endoglucanase genes in the GenBank database, this gene displays five differences (including T740C,A874G,A983G, T1210G and T1301C), which leading to five amino acid changes. Homology modeling has indicated that these five changes were located in the α-helix and random coil regions of the glycosyl hydrolase family 5 (GH5) domain, the random coil and ß-sandwich of the type 3 carbohydrate-binding module (CBM3) domain, and the random coil domain. Aprokaryotic expression vector pET30a-endoglucanase was constructed and the endoglucanase was induced to express. The expressed endoglucanase was confirmed by liquid chromatography-tandem mass spectrometry (LC-MSMS) and detected via reaction with carboxymethyl cellulose. In order to obtain the highest expression level of endoglucanase, the expression conditions including IPTG concentration, temperature and pH were optimized. The recombinant endoglucanase protein was purified using a Ni-NTA column, and the 6 × His-tag was removed with thrombin. The results showed that both the modified and unmodified purified endoglucanase had high activity (7.65 ± 0.35 U and 15.05 ± 1.81 U, respectively), thus demonstrating the potential use of this enzyme in various industrial applications. The substitutions of L247P,N292D, F404V and L434P might contribute to the activity of the endoglucanase, and the insertion of a 6 × His-tag at the N-terminal of the endoglucanase might also affect its activity.