Association of Polyphenols from Oranges and Apples with Specific Intestinal Microorganisms in Systemic Lupus Erythematosus Patients

Our group has recently shown the existence of a gut microbial dysbiosis in systemic lupus erythematosus (SLE), supporting previous evidence involving intestinal bacteria in the initiation and amplification of autoimmune diseases. While several studies have addressed the use of dietary fibres to modify intestinal microbiota, information about other correlated components, such as polyphenols, is scarce. The aim of this work was to identify dietary components able to influence this altered microbiota in 20 SLE women and 20 age-matched controls. Food intake was recorded by means of a food frequency questionnaire. The intake of fibres was calculated from Marlett tables, and Phenol-Explorer was used for polyphenol consumption. Results showed positive associations between flavone intake and Blautia, flavanones and Lactobacillus, and dihydrochalcones and Bifidobacterium in the SLE group. Regarding the controls, dihydroflavonols were directly associated with Faecalibacterium, whereas flavonol intake was inversely associated with Bifidobacterium. From the food sources of these polyphenols related to microbiota, orange intake was directly associated with Lactobacillus and apple with Bifidobacterium in SLE, whilst red wine was the best contributor to Faecalibacterium variation. The association between common foods and particular microbial genera, reported to be decreased in SLE, could be of great importance for these patients.     

Chronic obstructive pulmonary disease and asthma-associated Proteobacteria,but not commensal Prevotella spp., promote Toll-like receptor 2-independent lung inflammation and pathology

Recent studies of healthy human airways have revealed colonization by a distinct commensal bacterial microbiota containing Gram-negative Prevotella spp. However, the immunological properties of these bacteria in the respiratory system remain unknown. Here we compare the innate respiratory immune response to three Gram-negative commensal Prevotella strains (Prevotella melaninogenica, Prevotella nanceiensis and Prevotella salivae) and three Gram-negative pathogenic Proteobacteria known to colonize lungs of patients with chronic obstructive pulmonary disease (COPD) and asthma (Haemophilus influenzae B, non-typeable Haemophilus influenzae and Moraxella catarrhalis). The commensal Prevotella spp. and pathogenic Proteobacteria were found to exhibit intrinsic differences in innate inflammatory capacities on murine lung cells in vitro. In vivo in mice, non-typeable H. influenzae induced severe Toll-like receptor 2 (TLR2)-independent COPD-like inflammation characterized by predominant airway neutrophilia, expression of a neutrophilic cytokine/chemokine profile in lung tissue, and lung immunopathology. In comparison, P. nanceiensis induced a diminished neutrophilic airway inflammation and no detectable lung pathology. Interestingly, the inflammatory airway response to the Gram-negative bacteria P. nanceiensis was completely TLR2-dependent. These findings demonstrate weak inflammatory properties of Gram-negative airway commensal Prevotella spp. that may make colonization by these bacteria tolerable by the respiratory immune system.     

粪菌移植在儿科应用的研究进展北大核心CSCD

粪菌移植(FMT)可将健康人粪便中的各种肠道微生物、代谢产物和天然抗菌物质等移植到受者肠道内,可重建肠道菌群平衡、修复肠黏膜屏障、控制炎症反应、调节机体免疫,是治疗肠道菌群失调所致疾病的新方法。FMT治疗儿童复发性艰难梭菌感染已写入复发性艰难梭菌感染的诊疗指南。FMT治疗儿童炎症性肠病、孤独症谱系障碍的有效性及安全性较好。     

Dietary polyphenols increase fecal mucin and immunoglobulin A and ameliorate the disturbance in gut microbiota caused by a high fat diet

The effects of dietary polyphenols on human health have mainly been discussed in the context of preventing degenerative diseases, particularly cardiovascular diseases and cancer. The antioxidant properties of polyphenols have been widely studied, but it has become clear that the mechanism of action of polyphenols extends beyond the modulation of oxidative stress, as they are poorly absorbed from the digestive tract. The purpose of this study was to clarify the effects of polyphenols on the colonic environment, intestinal barrier function, and gut microbiota. We demonstrated that dietary polyphenols derived from aronia, haskap, and bilberry, markedly elevated the amount of fecal mucin and immunoglobulin A (IgA) as an intestinal barrier function and ameliorated the disturbance in gut microbiota caused by a high fat diet in rats. These results suggest that dietary polyphenols play a significant role in the prevention of degenerative diseases through improvement of the colonic environment without any absorption from the digestive tract.     

Effect of administering a multi-species probiotic mixture on the changes in fecal microbiota and symptoms of irritable bowel syndrome: a randomized,double-blind,placebo-controlled trial

We assessed the effect of multi-species probiotic mixture on the changes in fecal microbiota and irritable bowel syndrome (IBS) symptoms. Eighty-one IBS patients were randomly assigned to receive either probiotic mixture (n = 39; containing Lactobacillus acidophilus, L. rhamnosus, Bifidobacterium breve, B. actis, B. longum, and Streptococcus thermophilus) or placebo (n = 42) for 4 weeks. A questionnaire regarding general symptom relief was administered. The change in total symptom scores (sum of 10 IBS symptoms) and subtotal scores in 4 domains (pain, constipation, diarrhea, and bloating/gas) were evaluated. The change in fecal flora was determined by quantitative real-time PCR. The concentration of probiotic strains significantly increased after ingestion in probiotics group (B. bifidum, p = 0.043; B. lactis, p<0.001; L. acidophilus, p = 0.016; L. rhamnosus, p<0.001). The proportion of patients with adequate symptom relief was higher in probiotics group than in placebo group (74.4% vs 61.9%, p = 0.230). The decrease in total symptom score over time was not significantly different between the groups (p = 0.703). Among subtotal scores of 4 IBS symptom domains, the time effect was significantly different for diarrhea-symptom score between the groups (p = 0.017). A 4-week administration of multi-species probiotic mixture significantly increased the fecal concentration of most probiotic strains and improved diarrhea-symptom scores in IBS patients.     

Bacterial cell wall components regulate adipokine secretion from visceral adipocytes

Recent studies suggest a relationship between intestinal microbiota and metabolic syndromes; however, the underlying mechanism remains unclear. To clarify this issue, we assessed the effects of bacterial cell wall components on adiponectin, leptin and resistin secretion from rat visceral adipocytes in vitro. We also measured the relative population of Firmicutes and Bacteroidetes in fecal microbiota and the amount of fecal mucin as an intestinal barrier function, when mice were fed a high-fat diet. In the present study, we demonstrated that bacterial cell wall components affect the secretion of adipokines, depending on the presence of antigens from gram-positive or gram-negative bacteria. Lipopolysaccharide markedly inhibited adiponectin, leptin, and resistin secretion, whereas peptidoglycan increased adiponectin secretion and decreased resistin secretion in vitro. In vivo experiments showed that the high-fat diet increased the population of Firmicutes and decreased that of Bacteroidetes. In contrast, the high-fat diet downregulated the stool output and fecal mucin content. These results demonstrate that bacterial cell wall components affect the onset of metabolic syndromes by mediating the secretion of adipokines from visceral adipose tissue. Furthermore, we believe that metabolic endotoxemia is not due to the increasing dominance of gram-negative bacteria, Bacteroidetes, but due to the depression of intestinal barrier function.     

16S rDNA测序技术在婴儿肠道微生态研究中的应用

目的探讨16SrDNA测序技术在新生儿、婴儿肠道微生态研究中的应用。方法于生后3天、1月、6月、1岁时收集2例健康婴儿粪便标本共8份,提取细菌总DNA,以Illumina Hiseq 2000为测序平台,采用新一代高通量16SrDNA宏基因组测序技术对V6可变区测序,并进行生物信息分析(物种分类和丰度分析;多样性分析)。结果 8份样品共产生原始测序数据为1 027.47 Mbp,Unique tags序列数量均值为58630,OTU数量63~209;优势菌门为Proteobacteria和Firmicutes;在科水平,1%的物种1个月之内2~4种,6月后达7~10种;1号婴儿一直以Enterobacteriaceae占优势,2号婴儿优势菌群包括Enterobacteriaceae、Lachnospiraceae、Streptococcaceae和Bacteroidaceae;4个时间点的npShannon和Simpson指数分别为1.17、1.29、2.16、2.51和0.43、0.40、0.26、0.14。结论 16SrDNA测序技术能满足新生儿、婴儿肠道微生态研究需求;新生儿、婴儿粪便中含丰富细菌基因组;细菌物种丰度及分类存在个体差异;从出生到1岁,婴儿肠道菌群结构趋向复杂和多样。     

Diversity and functional prediction of gut microbiota in children with autism spectrum disorder北大核心CSCD

目的分析孤独症谱系障碍(autism spectrum disorder,ASD)儿童肠道菌群结构和多样性,并预测分析菌群的代谢功能。方法采集30例ASD儿童(ASD组)和20例正常发育(typically developing,TD)儿童(TD组)的粪便样本。提取基因组DNA,PCR扩增16S rDNA V4区,使用Illumina NovaSeq6000平台进行高通量测序。分析2组肠道菌群的构成和分布特征,并预测分析菌群的代谢功能。结果ASD组和TD组儿童肠道菌群的α多样性指数(Chao1、Shannon和Simpson)比较差异均无统计学意义(P>0.05)。在门和纲水平,2组儿童肠道菌群的结构差异无统计学意义(P>0.05)。在属水平,ASD组巨单胞菌属、巴恩斯氏菌属、小杆菌属、巨球菌属、瘤胃球菌属扭链群及梭杆菌属的丰度大于TD组(P<0.05)。功能预测分析显示,ASD组肠道菌群的色氨酸降解、谷氨酸降解及丁酸盐生成等代谢功能的丰度低于TD组(P<0.05),而γ-氨基丁酸降解功能的丰度高于TD组(P<0.05)。结论ASD儿童和TD儿童肠道菌群的α多样性无显著差异,但属水平物种构成不同,菌群的代谢功能有差别。     

Metabolism of Chinese Materia Medica in Gut Microbiota and Its Biological Effects

The drug metabolism in gut microbiota draws increasing attentions. After interacting with the gut bacteria, the biological effects of drugs might be altered, leading to toxicity or detoxification, production of potential bioactivities, regulating intestinal absorption, etc. In this review, we will focus on the metabolism of Chinese materia medica(CMM) in mammal gut microbiota and its biological effects to learn the interaction between gut bacteria and drugs through oral route in CMM.