Dietary whole Goji berry (Lycium barbarum) intake improves colonic barrier function by altering gut microbiota composition in mice

Diet strongly affects human health by modulating gut microbiota (GM) composition. Lycium barbarum (LB), which contains polysaccharides and polyphenols, can alter the GM and intestinal barrier function, thereby reducing and preventing the occurrence of intestinal diseases. To investigate how LB improves colonic barrier function, male C57BL/6J mice were fed diets containing 1.5% or 3% LB for 10 weeks. Results of HiSeq 16S rDNA analysis showed that LB markedly altered microbial profile by supporting the growth of Verrucomicrobia, Bacteroidetes, Bacteroidales_S24-7_group, Anaerotruncus, Coprococcus_1, Ruminococcaceae_UCG-014 and Akkermansia, while suppressing Firmicutes, Helicobacter, Bacteroides and Mucispirillum. LB supported the short-chain fatty acid (SCFA)-producing bacteria, and the SCFA concentrations increased, while the ammonia concentrations and pH values in faeces decreased, thereby increasing the expression of tight junction proteins and mucin, subsequently improving intestinal function and histomorphology. Dietary LB, as a functional dietary component, enhanced colonic barrier function and improved gut health by altering GM composition.     

Green tea polyphenols reduce obesity in high‐fat diet‐induced mice by modulating intestinal microbiota composition

In this study, the modulatory effect of green tea polyphenols (GTP) on human intestinal microbiota was investigated. Firstly, germ‐free mice were inoculated with faecal suspension derived from healthy volunteers to obtain human flora‐associated (HFA) mice model. When the high‐fat diet‐induced obese mice model was successfully established, they were randomly divided into high‐fat diet group (HFD) and high‐fat diet group with GTP (HFD‐GTP), and the shifts in relative abundance of the dominant taxa at the phylum, family and genus levels were studied by high‐throughput sequencing. The diversity of the total bacterial community reached the maximum after GTP treatment for 3 weeks, and then decreased when the mice were fed without GTP. Despite interindividual variation, the relative abundance of Bacteroidetes increased from 0.56 ± 0.06 (1st week) to 0.60 ± 0.05 (3th week), while Firmicutes decreased from 0.42 ± 0.06 to 0.37 ± 0.02. Interestingly, certain bacterial communities such as Bacteroidetes and Proteobacteria still increased and Firmicutes showed a decreasing trend when the mice were fed without GTP (4th week). The results showed that GTP benefits the stability of certain gut microbiota, especially in an environment‐triggered microbial imbalance; therefore, it may have prebiotic‐like activity contributing to the prevention of obesity.     

唾液乳杆菌CCFM 1054通过改变肠道菌群缓解空肠弯曲杆菌在小鼠体内的感染

考察了唾液乳杆菌(Lactobacillus salivarius) CCFM 1054体外培养产酸及发酵上清液抑制空肠弯曲杆菌(Campylobacter jejuni)生长能力、对人工模拟胃肠液中的耐受、对共培养条件下的抑菌能力、对HT-29细胞的粘附以及自我形成生物膜的能力,并以鼠李糖乳杆菌LGG和植物乳杆菌N49作为对比菌株,分别干预空肠弯曲杆菌和弓形虫复合感染的小鼠。结果显示,CCFM 1054能显著改变小鼠肠道菌群的组成,降低空肠弯曲杆菌在小鼠体内的定植率并缓解其感染。肠道菌群变化和乳酸菌拮抗空肠弯曲杆菌相关的体内外特性的相关性分析表明,CCFM 1054对细胞的高粘附性及其较强的生物膜形成能力使得其能在小鼠体内显著改变肠道菌群丰度。