The abundance of antibiotic resistance genes in human guts has correlation to the consumption of antibiotics in animal

Increasing evidence has accumulated to support that the human gut is a reservoir for antibiotic resistance genes. We previously identified more than 1000 genes displaying high similarity with known antibiotic resistance genes in the human gut gene set generated from the Chinese, Danish, and Spanish populations. Here, first, we add our new understanding of antibiotic resistance genes in the US and the Japanese populations; next, we describe the structure of a vancomycin-resistant operon in a Danish sample; and finally, we provide discussions on the correlation of the abundance of resistance genes in human gut with the antibiotic consumption in human medicine and in animal husbandry. These results, combined with those we published previously, provide comprehensive insights into the antibiotic resistance genes in the human gut microbiota at a population level.     

The abundance of antibiotic resistance genes in human guts has correlation to the consumption of antibiotics in animal

Increasing evidence has accumulated to support that the human gut is a reservoir for antibiotic resistance genes. We previously identified more than 1000 genes displaying high similarity with known antibiotic resistance genes in the human gut gene set generated from the Chinese, Danish, and Spanish populations. Here, first, we add our new understanding of antibiotic resistance genes in the US and the Japanese populations; next, we describe the structure of a vancomycin-resistant operon in a Danish sample; and finally, we provide discussions on the correlation of the abundance of resistance genes in human gut with the antibiotic consumption in human medicine and in animal husbandry. These results, combined with those we published previously, provide comprehensive insights into the antibiotic resistance genes in the human gut microbiota at a population level.     

肠道菌群与肾移植

了解肾移植受者肠道菌群的构成及其变化对改善肾移植受者短期及长期预后具有重要的意义。现有研究显示肾移植受者存在肠道菌群失调的情况,特别是出现并发症时,通过改善肾移植受者肠道菌群失调来提高患者预后具有治疗前景。本文旨在阐述肠道菌群在肾移植的最新研究进展。     

肠道菌群和心血管疾病的免疫调节

心血管疾病是人类健康的第一杀手,发病率和死亡率逐年增加。数万亿微生物寄居于人类肠道,在心血管疾病及其相关的代谢、免疫反应中发挥着至关重要的作用。先天性和适应性免疫机制都参与了心血管疾病的发生发展,菌群组分和代谢产物可调节巨噬细胞、淋巴细胞等免疫细胞的分化及功能,并通过循环系统影响机体免疫稳态。本文将通过肠道菌群及其代谢产物与免疫系统的相互作用,讨论肠道菌群与心血管疾病发展之间潜在的免疫机制,为预防和治疗心血管疾病提供新思路。     

肠道菌群：功能性胃肠病的防治新靶点

功能性胃肠病（FGIDs）是一组无器质性改变但存在消化功能异常的疾病,是消化科门诊中常见疾病之一。在 最新的罗马Ⅳ标准中将功能性肠胃病定义为脑-肠互动异常疾病。肠道菌群在脑-肠互动中发挥重要作用,参与功 能性胃肠病发生的多种病理生理机制。肠道菌群失调主要通过增加肠道渗透及内脏高敏感性、改变肠道动力和激活 免疫反应参与FGIDs症状产生。因此,重塑肠道菌群稳态的策略在治疗FGIDs中显示出一定的前景。     

Considering gut microbiota disturbance in the management of Helicobacter pylori infection

Introduction: Helicobacter pylori (Hp) infection produces drastic changes in the gastric microenvironment, which, in turn, influence the gastric microbiota composition and might be correlated with large intestinal microbiota changes. This excellent perturbing actor could trigger important modifications in the homeostatic functions exerted by gut commensals leading to a new gastrointestinal balance. At the same time, the therapeutic strategies used to eradicate Hp can modulate this physiological symbiosis, but can be also conversely affected by its properties.

Area covered: The purpose of this review is to explore the reciprocal interplay between Hp infection and gut microbiota and analyze how microbial changes can influence the management of Hp eradication therapies.

Expert commentary: While many studies have described Hp-dependent gut microbiota alterations, their clinical implications are only partially clear, as well as the mechanism of actions that sustain these processes. This represents a clear challenge for future research projects that will also need to understand which role is exerted by viruses, parasites, and yeasts.     

Gut microbiota dysbiosis in patients with non-alcoholic fatty liver disease

BACKGROUND: Gut microbiota plays a significant role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). This study aimed to assess the contribution of gut microbiota dysbiosis to the pathogenesis of NAFLD. METHODS: Forty-seven human feces samples (25 NAFLD patients and 22 healthy subjects) were collected and 16S rDNA amplicon sequencing was conducted on Hiseq 2000 platform. Discrepancy of species composition between controls and NAFLD group was defined by Metastats analysis under P value<0.01. RESULTS: NAFLD patients harbored lower gut microbiota diversity than healthy subjects did. In comparison to the control group, the Proteobacteria (13.50%) and Fusobacteria (2.76%) phyla were more abundant in NAFLD patients. Ad-ditionally, the Lachnospiraceae (21.90%), Enterobacteriaceae (12.02%), Erysipelotrichaceae (3.83%), and Streptococcaceae (1.39%) families, as well as the Escherichia_Shigella (10.84%), Lachnospiraceae_Incertae_Sedis (7.79%), and Blautia (4.95%) genera were enriched in the NAFLD group. However, there was a lower abundance of Prevotella in the NAFLD group than that in the control group (5.83% vs 27.56%, P<0.01). The phylum Bacteroidetes (44.63%) also tended to be more abundant in healthy subjects, and the families Prevotellaceae (28.66%) and Ruminococcaceae (26.44%) followed the same trend. Compared to those without non-alcoholic steatohepa-titis (NASH), patients with NASH had higher abundance of genus Blautia (5.82% vs 2.25%; P=0.01) and the correspond-ing Lachnospiraceae family (24.33% vs 14.21%; P<0.01). Patients with significant fibrosis had a higher abundance of genus Escherichia_Shigella (12.53% vs 1.97%; P<0.01) and the corresponding Enterobacteriaceae family (13.92% vs 2.07%;P<0.01) compared to those with F0/F1 fibrosis. CONCLUSIONS: NAFLD patients and healthy subjects harbor varying gut microbiota. In contrast to the results of previous research on children, decreased levels of Prevotella might be detrimental for adults with NAFLD. The increased level of the genus Blautia, the family Lachnospiraceae, the genus Escherichia_Shigella, and the family Enterobacteriaceae may be a primary contributor to NAFLD progression.     

Gut microbiota in ulcerative colitis: insights on pathogenesis and treatment

Gut microbiota constitute the largest reservoir of the human microbiome and are an abundant and stable ecosystem—based on its diversity, complexity, redundancy, and host interactions This ecosystem is indispensable for human development and health. The integrity of the intestinal mucosal barrier depends on its interactions with gut microbiota. The commensal bacterial community is implicated in the pathogenesis of inflammatory bowel disease (IBD), including ulcerative colitis (UC). The dysbiosis of microbes is characterized by reduced biodiversity, abnormal composition of gut microbiota, altered spatial distribution, as well as interactions among microbiota, between different strains of microbiota, and with the host. The defects in microecology, with the related metabolic pathways and molecular mechanisms, play a critical role in the innate immunity of the intestinal mucosa in UC. Fecal microbiota transplantation (FMT) has been used to treat many diseases related to gut microbiota, with the most promising outcome reported in antibiotic‐associated diarrhea, followed by IBD. This review evaluated the results of various reports of FMT in UC. The efficacy of FMT remains highly controversial, and needs to be regularized by integrated management, standardization of procedures, and individualization of treatment.     

Gut microbiota changes in patients with hypertension: A systematic review and meta-analysis

Hypertension is a major public health issue worldwide. The imbalance of gut microbiota is thought to play an important role in the pathogenesis of hypertension. The authors conducted the systematic review and meta-analysis to clarify the relationship between gut microbiota and hypertension through conducting an electronic search in six databases. Our meta-analysis included 19 studies and the results showed that compared with healthy controls, Shannon significantly decreased in hypertension [SMD = −0.13, 95%CI (−0.22, −0.04), p = .007]; however, Simpson [SMD = −0.01, 95%CI (−0.14, 0.12), p = .87], ACE [SMD = 0.18, 95%CI (−0.06, 0.43), p = .14], and Chao1 [SMD = 0.11, 95%CI (−0.01, 0.23), p = .08] did not differ significantly between hypertension and healthy controls. The F/B ratio significantly increased in hypertension [SMD = 0.84, 95%CI (0.10, 1.58), p = .03]. In addition, Shannon index was negatively correlated with hypertension [r = −0.12, 95%CI (−0.19, −0.05)], but had no significant correlation with SBP [r = 0.10, 95%CI (−0.19, 0.37)] and DBP [r = −0.39, 95%CI (−0.73, 0.12)]. At the phylum level, the relative abundance of Firmicutes [SMD = −0.01, 95%CI (−0.37, 0.34), p = .94], Bacteroidetes [SMD = −0.15, 95%CI (−0.44, 0.14), p = .30], Proteobacteria [SMD = 0.25, 95%CI (−0.01, 0.51), p = .06], and Actinobacteria [SMD = 0.21, 95%CI (−0.11, 0.53), p = .21] did not differ significantly between hypertension and healthy controls. At the genus level, compared with healthy controls, the relative abundance of Faecalibacterium decreased significantly [SMD = −0.16, 95%CI (−0.28, −0.04), p = .01], while the Streptococcus [SMD = 0.20, 95%CI (0.08, 0.32), p = .001] and Enterococcus [SMD = 0.20, 95%CI (0.08, 0.33), p = .002] significantly increased in hypertension. Available evidence suggests that hypertensive patients may have an imbalance of gut microbiota. However, it still needs further validation by large sample size studies of high quality.     

Gut microbiota in obesity

Obesity is a major global health problem determined by heredity and environment, and its incidence is increasing yearly. In recent years, increasing evidence linking obesity to the gut microbiota has been reported. Gut microbiota management has become a new method of obesity treatment. However, the complex interactions among genetics, environment, the gut microbiota, and obesity remain poorly understood. In this review, we summarize the characteristics of the gut microbiota in obesity, the mechanism of obesity induced by the gut microbiota, and the influence of genetic and environmental factors on the gut microbiota and obesity to provide support for understanding the complex relationship between obesity and microbiota. At the same time, the prospect of obesity research related to the gut microbiota is proposed.     

Gut microbiota in autism and mood disorders

The hypothesis of an important role of gut microbiota in the maintenance of physiological state into the gastrointestinal (GI) system is supported by several studies that have shown a qualitative and quantitative alteration of the intestinal flora in a number of gastrointestinal and extra-gastrointestinal diseases. In the last few years, the importance of gut microbiota impairment in the etiopathogenesis of pathology such as autism, dementia and mood disorder, has been raised. The evidence of the inflammatory state alteration, highlighted in disorders such as schizophrenia, major depressive disorder and bipolar disorder, strongly recalls the microbiota alteration, highly suggesting an important role of the alteration of GI system also in neuropsychiatric disorders. Up to now, available evidences display that the impairment of gut microbiota plays a key role in the development of autism and mood disorders. The application of therapeutic modulators of gut microbiota to autism and mood disorders has been experienced only in experimental settings to date, with few but promising results. A deeper assessment of the role of gut microbiota in the development of autism spectrum disorder (ASD), as well as the advancement of the therapeutic armamentarium for the modulation of gut microbiota is warranted for a better management of ASD and mood disorders.     

Gut microbiota in toxicological risk assessment of drugs and chemicals: The need of hour

ABSTRACT

The advent of industrial revolution caused a large inflow of synthetic chemicals for medical, agricultural, industrial and other purposes in the world. In general, these chemicals were subjected to toxicological risk assessment for human health and ecology before release for public use. But today we are witnessing a negative impact of some of these chemicals on human health and environment indicating an underestimation of toxic effects by current risk assessment protocol. Recent studies established gut microbiota as one of the key player in intercession of toxicity of drugs and synthetic chemicals. Hence, the need of the hour is to include the assessment for microbiota specifically gut microbiota in human toxicological risk assessment protocol. Herewith we are proposing a framework for assessment of gut microbiota upon exposure to drugs or chemicals.     

Gut mycobiota and adenomas

Fungal microbiota (mycobiota) is potentially involved in the intestinal illness. The characterization of the mycobiota in patients with adenomas is essential for understanding the etiology of the pre-cancerous lesion since the mycobiota is potentially associated with the presents of adenomas. The recovery of the mycobiome may also help to identify the potential biomarkers which may closely relate to different stages of adenoma.     

Gut microbiota mediated molecular events and therapy in liver diseases

Gut microbiota is a community of microorganisms that reside in the gastrointestinal tract. An increasing number of studies has demonstrated that the gut-liver axis plays a critical role in liver homeostasis. Dysbiosis of gut microbiota can cause liver diseases, including nonalcoholic fatty liver disease and alcoholic liver disease. Preclinical and clinical investigations have substantiated that the metabolites and other molecules derived from gut microbiota and diet interaction function as mediators to cause liver fibrosis, cirrhosis, and final cancer. This effect has been demonstrated to be associated with dysregulation of intrahepatic immunity and liver metabolism. Targeting these findings have led to the development of novel preventive and therapeutic strategies. Here, we review the cellular and molecular mechanisms underlying gut microbiota-mediated impact on liver disease. We also summarize the advancement of gut microbiota-based therapeutic strategies in the control of liver diseases.     

Gut mycobiota and adenomas

Fungal microbiota (mycobiota) is potentially involved in the intestinal illness. The characterization of the mycobiota in patients with adenomas is essential for understanding the etiology of the pre-cancerous lesion since the mycobiota is potentially associated with the presents of adenomas. The recovery of the mycobiome may also help to identify the potential biomarkers which may closely relate to different stages of adenoma.     

Gut microbiota remodeling reverses aging-associated inflammation and dysregulation of systemic bile acid homeostasis in mice sex-specifically

ABSTRACT

Aging is usually characterized with inflammation and disordered bile acids (BAs) homeostasis, as well as gut dysbiosis. The pathophysiological changes during aging are also sexual specific. However, it remains unclear about the modulating process among gut microbiota, BA metabolism, and inflammation during aging. In this study, we established a direct link between gut microbiota and BA profile changes in the liver, serum, and four intestinal segments of both sexes during aging and gut microbiota remodeling by co-housing old mice with young ones. We found aging reduced Actinobacteria in male mice but increased Firmicutes in female mice. Among the top 10 altered genera with aging, 4 genera changed oppositely between male and female mice, and most of the changes were reversed by co-housing in both sexes. Gut microbiota remodeling by co-housing partly rescued the systemically dysregulated BA homeostasis induced by aging in a sex- and tissue-specific manner. Aging had greater impacts on hepatic BA profile in females, but intestinal BA profile in males. In addition, aging increased hepatic and colonic deoxycholic acid in male mice, but reduced them in females. Moreover, muricholic acids shifted markedly in the intestine, especially in old male mice, and partially reversed by co-housing. Notably, the ratios of primary to secondary BAs in the liver, serum, and all four intestinal segments were increased in old mice and reduced by co-housing in both sexes. Together, the presented data revealed that sex divergent changes of gut microbiota and BA profile in multiple body compartments during aging and gut microbiota remodeling, highlighting the sex-specific prevention and treatment of aging-related disorders by targeting gut microbiota-regulated BA metabolism should particularly be given more attention.     

肠道菌群与胰岛素抵抗

IR是T2DM的重要特征,也是代谢性疾病的共同病理基础.肠道菌群与机体能量代谢密切相关,且与IR、肥胖和糖尿病发生存在关联.本文就肠道菌群与IR的相互关系作一概述.