Changes in polyphenol fractions and bacterial composition after in vitrofermentation of apple peel polyphenol by gut microbiota

The changes in polyphenol fractions after in vitro fermentation of apple peel polyphenol (APP) by gut microbiota as well as the effects of APP on the growth, pH value, short-chain fatty acids (SCFAs) production and intestinal flora composition of gut microbiota fermentation were firstly explored in this study. The relative abundance of Lactobacillus in the APP group was 49.55% with an increment of 49.40% compared with the blank group, while that of Bifidobacterium was 13.32%. Moreover, the flora produced 37.093 ± 0.478 mM of SCFAs including acetic acid, propionic acid, butyric acid and valeric acid during the process of fermentation, thus reduced the environmental pH value. In addition, polyphenol fractions in APP were altered by gut microbiota fermentation to some extent, for example, glycosides were hydrolysed to aglycones. These findings suggested APP as a potential prebiotic agent to alleviate the disorder of intestinal flora.     

Designing amorphous formulations of polyphenols with naringin by spray-drying for enhanced solubility and permeability

Naringin (NAR), a major flavanone (FVA) glycoside, is a component of food mainly obtained from grapefruit. We used NAR as a food additive to improve the solubility and permeability of hydrophobic polyphenols used as supplements in the food industry. The spray-dried particles (SDPs) of NAR alone show an amorphous state with a glass transition temperature (T_g) at 93.2 °C. SDPs of hydrophobic polyphenols, such as flavone (FVO), quercetin (QCT), naringenin (NRG), and resveratrol (RVT) were prepared by adding varying amounts of NAR. All SDPs of hydrophobic polyphenols with added NAR were in an amorphous state with a single T_g, but SDPs of hydrophobic polyphenols without added NAR showed diffraction peaks derived from each crystal. The SDPs with NAR could keep an amorphous state after storage at a high humidity condition for one month, except for SDPs of RVT/NAR. SDPs with NAR enhanced the solubility of hydrophobic polyphenols, especially NRG solubility, which was enhanced more than 9 times compared to NRG crystal. The enhanced solubility resulted in the increased membrane permeability of NRG. The antioxidant effect of the hydrophobic NRG was also enhanced by the synergetic effect of NAR. The findings demonstrated that NAR could be used as a food additive to enhance the solubility and membrane permeability of hydrophobic polyphenols.     

Acceptive Immunity: The Role of Fucosylated Glycans in Human Host–Microbiome Interactions

The growth in the number of chronic non-communicable diseases in the second half of the past century and in the first two decades of the new century is largely due to the disruption of the relationship between the human body and its symbiotic microbiota, and not pathogens. The interaction of the human immune system with symbionts is not accompanied by inflammation, but is a physiological norm. This is achieved via microbiota control by the immune system through a complex balance of pro-inflammatory and suppressive responses, and only a disturbance of this balance can trigger pathophysiological mechanisms. This review discusses the establishment of homeostatic relationships during immune system development and intestinal bacterial colonization through the interaction of milk glycans, mucins, and secretory immunoglobulins. In particular, the role of fucose and fucosylated glycans in the mechanism of interactions between host epithelial and immune cells is discussed.     

Plasticity of Intestinal Epithelium: Stem Cell Niches and Regulatory Signals

The discovery of Lgr5+ intestinal stem cells (ISCs) triggered a breakthrough in the field of ISC research. Lgr5+ ISCs maintain the homeostasis of the intestinal epithelium in the steady state, while these cells are susceptible to epithelial damage induced by chemicals, pathogens, or irradiation. During the regeneration process of the intestinal epithelium, more quiescent +4 stem cells and short-lived transit-amplifying (TA) progenitor cells residing above Lgr5+ ISCs undergo dedifferentiation and act as stem-like cells. In addition, several recent reports have shown that a subset of terminally differentiated cells, including Paneth cells, tuft cells, or enteroendocrine cells, may also have some degree of plasticity in specific situations. The function of ISCs is maintained by the neighboring stem cell niches, which strictly regulate the key signal pathways in ISCs. In addition, various inflammatory cytokines play critical roles in intestinal regeneration and stem cell functions following epithelial injury. Here, we summarize the current understanding of ISCs and their niches, review recent findings regarding cellular plasticity and its regulatory mechanism, and discuss how inflammatory cytokines contribute to epithelial regeneration.     

系统性硬化症与肠道菌群的关系

肠道菌群对人类健康和疾病有着深远影响。不仅肠道菌群能影响宿主免疫系统发育,免疫系统本身也能改变肠道菌群。目前发现肠道菌群参与了多种自身免疫性疾病。研究发现,系统性硬化症(systemic sclerosis,SSc)患者肠道菌群紊乱较常见,胃肠道易受累,且其中一些特定菌属与SSc患者胃肠道受累严重程度相关。本文对SSc患者肠道菌群变化特点、肠道菌群与SSc消化系统运动障碍和纤维化的关系以及治疗方案等方面进行系统阐述。     

通过RRLC-Q-TOF MS和UPLC-QQQ MS分析原人参三醇型皂苷在人肠道菌群中的代谢产物

通过高分离度快速液相色谱-四极杆飞行时间质谱(RRLC-Q-TOF MS)和超高效液相色谱-三重四极杆质谱(UPLC-QQQ MS)法对原人参三醇型皂苷Re、Rg 1、Rg 2、Rh 1、Rf、F 1、R 1在人肠道菌群中的转化产物进行定性、定量分析,确定原人参三醇型皂苷的代谢产物、转化途径和60 h时的转化率。结果表明,人参皂苷Re的转化产物为人参皂苷Rg 1、Rg 2、Rh 1、F 1和PPT,转化率为91%;人参皂苷Rg 1的转化产物为人参皂苷Rh 1、F 1和PPT,转化率为80%;人参皂苷Rg 2的转化产物为人参皂苷Rh 1和PPT,转化率为73%;人参皂苷Rh 1和F 1主要通过PPT代谢,转化率分别为82%和81%;人参皂苷Rf的转化产物为人参皂苷Rh 1和PPT,转化率为89%;三七皂苷R 1的转化产物为人参皂苷Rg 1、R 2、Rh 1和PPT,转化率为79%。原人参三醇型皂苷类成分可被人肠道菌群代谢,主要通过丢失糖残基形成转化产物,而次级皂苷和苷元是人参在体内发挥药理作用的物质基础。     

茅台镇酱香型白酒酿造环境中真菌菌群多样性分析

采用高通量测序技术结合数理统计软件分析方法，系统研究茅台镇酱香型白酒不同酿造轮次生产环境中的真菌菌群结构及特征。7 个轮次中共检测到4 个真菌门、212 个真菌属。根据各菌门、属的相对丰度，子囊菌门（Ascomycota）和担子菌门（Basidiomycota）是茅台镇酱香型白酒酿造环节中各酿造轮次的优势菌门，节担菌属（Wallemia）、复膜孢酵母属（Saccharomycopsis）为各轮次绝对优势真菌属。不同轮次环境样品中真菌组成结构的相似度较高，但其各轮次标志性真菌属存在差异。7 个酿造轮次共有相同真菌属56 个，在各轮次占主导地位，特征性真菌属在各轮次当中相对丰度和占比较小但种类丰富。Ascomycota最强节点为德巴利酵母属（Debaryomyces），Basidiomycota最强节点为红酵母属（Rhodotorula）。本研究揭示了茅台镇酱香型白酒不同酿造轮次环境中真菌菌群结构及其特征，为深入研究酱香型白酒酿造机理以及对酿造环境中微生物结构的解析提供了参考依据。     

Effect of <i>Lycopus lucidus</i> Turcz. supplementation on gut microflora and short chain fatty acid composition in Crj: CD-1 mice

We investigated the diversity and composition of microflora in feces of Lycopus lucidus Turcz.-fed mice. In addition, we evaluated the production of major cytokines (Interleukin-6 and -10) which are related to inflammation and fatty acid composition of several tissues. 16S ribosomal DNA sequencing-based microbiome taxonomic profiling analysis was performed utilizing the EzBioCloud data base. Male mice fed on L. lucidus showed a significantly reduced number of lactic acid bacteria and coliform in the feces compared with the control group (p < 0.05). 16S rDNA sequencing analysis of fecal samples showed that L. lucidus supplementation decreased the community of harmful microflora (Enterobacteriaceae including Escherichia coli and Bacteroides sp.) in feces compared with the control group (p < 0.05). There were no significant differences in mRNA expression of cytokine IL-6 and IL-10 between the control and L. lucidus fed groups. The fecal fatty acid composition in the L. lucidus group had percentages of 4:0, 6:0, 8:0 and 10:0 in the intestine but those short chain fatty acids were not detected in the control group. Our results showed that L. lucidus supplementation influenced gut environment by decreasing harmful microflora and increased the percentages of several short fatty acids.