Purple sweet potato starch is a potential resource for resistant starch production. The effects of heat-moisture treatment (HMT) and enzyme debranching combined heat-moisture treatment (EHMT) on the morphological, crystallinity and thermal properties of PSP starches were investigated. The results indicated that, after HMT or EHMT treatments, native starch granules with smooth surface was destroyed to form a more compact, irregular and sheet-like structure. The crystalline pattern was transformed from C-type to B-type with decreasing relative crystallinity. Due to stronger crystallites formed in modified starches, the swelling power and solubility of HMT and EHMT starch were decreased, while the transition temperatures and gelatinization enthalpy were significantly increased. In addition, HMT and EHMT exhibited greater effects on the proliferation of bifidobacteria compared with either glucose or high amylose maize starch.
The change characteristics of intestinal microbial succession and the correlation with the production of two important types of bacterial metabolites (short chain fatty acids and bioamine) in piglets during the early stage were fully explored in this study. Six piglets from different litters with the same birth time were selected, weighted and euthanized at 1, 7, 14, 21, 28, 35, and 42 days of age. During this stage, the piglets grew quickly with gradual increases in blood levels of growth hormone and insulin, and in the intestinal developmental index and immunity. 16s rRNA analysis indicated the alpha diversity of colonic microbiome community was higher than ileum. However, the composition change in the ileal microbiota was more dramatic over time. Lactobacillus genus was the dominant bacteria in piglets' ileum while Prevotella and Ruminococcaceae genera were the dominant bacteria in colon up to weaning. Gut bacterial community of the piglets showed obvious differences between the three different phases: newborn, before weaning, and post weaning. This was similar to the morphological change pattern of pigs' gut. Total SCFA content in the colon of pigs showed almost a 20-fold increase at day 42 compared to the value at day 1. The percentage of acetic acid among the total SCFAs dropped quickly from 74.5% at day 1 to 36.5% at day 42, while butyric acid and propionic acid showed significant increases at the stage. The histamine level increased and putrescine level decreased markedly in the colon with time while the amounts of total bioamines, tyramine and spermidine were devoid of changes. Dozens bacteria taxa showed highly correlations with SCFAs and bioamines. These findings provide an expanded view of the dynamic pig gut and gut microbiome at the important early growth stage.
Lotus is an edible and medicinal plant, and the extracts from its different parts exhibit various bioactivities. In the present study, the hot water–soluble polysaccharides from lotus seeds (LSPS) were evaluated for their cancer cell cytotoxicity, immunomodulatory and antitumor activities. LSPS showed significant inhibitory effects on the mouse gastric cancer MFC cells, human liver cancer HuH-7 cells and mouse hepatocarcinoma H22 cells. The animal studies showed that LSPS inhibited tumor growth in H22 tumor-bearing mice with the highest inhibition rate of 45.36%, which is comparable to that induced by cyclophosphamide (30 mg/kg) treatment (50.79%). The concentrations of white blood cells were significantly reduced in cyclophosphamide-treated groups (p < 0.01), while LSPS showed much fewer side effects according to the hematology analysis. LSPS improved the immune response in H22 tumor-bearing mice by enhancing the spleen and thymus indexes, and increasing the levels of serum cytokines including tumor necrosis factor-α and interleukin-2. Moreover, LSPS also showed in vivo antioxidant activity by increasing superoxide dismutase activity, thus reducing the malondialdehyde level in the liver tissue. These results suggested that LSPS can be used as an antitumor and immunomodulatory agent.
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.
Fermentation of mulberry juice not only improves its shelf life, but also effectively enhances their flavor and nutritional quality. This study elucidated the phytochemical and flavor characteristics of mulberry juice fermented with Lactiplantibacillus plantarum BXM2, originally isolated from naturally fermented fruit beverage, through widely targeted metabolomics. The fermentation produced the unique flavor of fermented juice and decreased the pH from 4.15 to 3.19. The metabolomic analysis detected 907 non-volatile metabolites, from which 359 significantly different non-volatile metabolites (up 238, down 121) were screened out. Among 731 identified volatile metabolites, 26 flavor substances were the major contributors to the flavor differences between fermented and unfermented mulberry juices. It is hypothesized that lipid metabolism and amino acid catabolism are crucial pathways for the flavor enhancement of mulberry juice fermented with L. plantarum BXM2. Meanwhile, significant increases of the contents of a variety of bioactive substances, such as indole-3-lactic acid, octadeca-9,12,15-trienoic acid, di-/tri-peptides, etc., conferred additional health potential to BXM2-fermented mulberry juice.