Objective To assess any potential associations between lung cancer and gut microbiota. Methods Mendelian randomization (MR) analysis was carried out by utilizing summary data from genome-wide association studies (GWAS) of the gut microbiota and lung cancer. The gut microbiota served as an exposure. Instrumental ariables (IVs) were identified from the GWAS of 18340 participants. The GWAS study of lung cancer from Europe served as an outcome, including 29 266 lung cancer patients and 56450 controls. We used the inverse-variance weighted (IVW) method as the primary analysis. Sensitivity analysis was used to test the reliability of MR analysis results. Results IVW results showed that Genus Parabacteroides (OR=1.258, 95%CI 1.034 to 1.531, P=0.022) and Phylum Bacteroidetes (OR=1.192, 95%CI 1.001 to 1.419, P=0.048) had a positive causal association with lung cancer, and there was a negative causal association between family Bifidobacteriaceae (OR=0.845, 95%CI 0.721 to 0.989, P=0.037) and order Bifidobacteriales (OR=0.865, 95%CI 0.721 to 0.989, P=0.037) with lung cancer. Sensitivity analysis showed no evidence of reverse causality, pleiotropy, and heterogeneity. Conclusion This study demonstrates that Genus Parabacteroides and Phylum Bacteroidetes are related to an increased risk of lung cancer, family Bifidobacteriaceae and order Bifidobacteriales can reduce the risk of lung cancer. Our thorough investigations provide evidence in favor of a potential causal relationship between a number of gut microbiota-taxa and lung cancer. To demonstrate how gut microbiota influences the development of lung cancer, further research is necessary.
ObjectiveTo explore the composition of intestinal microbiota between patients with fixed airflow obstruction asthma, reversible airflow obstruction asthma, and healthy control, and analyze the correlation between key differential bacterial distribution and clinical characteristics. MethodsFifteen patients with fixed airflow obstruction asthma (FAO) and 13 patients with reversible airflow obstruction asthma (RAO) were included, along with 11 matched healthy control subjects. Clinical data were collected, and lung function tests and induced sputum examination were performed. Blood and stool samples were tested to compare the gut microbiota status among the groups, and analyze the relationship between gut microbiota abundance and patients' blood routine, IgE levels, lung function, and induced sputum. Results The dominant bacterial compositions were similar in the three groups, but there were differences in the abundance of some species. Compared to the RAO group, the FAO group showed a significant increase in the genera of Bacteroides and Escherichia coli, while Pseudomonas was significantly decreased. The phylum Firmicutes was negatively correlated with the course of asthma, while the phylum Bacteroidetes and genus Bacteroides were positively correlated with the asthma course. Bacteroidetes was negatively correlated with Pre-BD FEV1/FVC, Pseudomonas was positively correlated with Pre-BD FEV1, Escherichia coli was negatively correlated with Post-BD FEV1/FVC, and Bacteroides was negatively correlated with Post-BD MMEF. The class Actinobacteria and the order Actinomycetales were negatively correlated with peripheral blood EOS%, while the order Enterobacteriales and the family Enterobacteriaceae were positively correlated with peripheral blood IgE levels. Furthermore, Actinobacteria and Actinomycetales were negatively correlated with induced sputum EOS%. Conclusions There are differences in the gut microbiota among patients with fixed airflow obstruction asthma, reversible airflow obstruction asthma, and healthy individuals. Bacteroides and Escherichia coli are enriched in the fixed airflow obstruction asthma group, while the Firmicutes are increased in the reversible airflow obstruction asthma group. These three microbiota may act together on Th2 cell-mediated inflammatory responses, influencing the process of airway remodeling, and thereby interfering with the occurrence of fixed airflow obstruction in asthma.
As a heterogeneous disease characterized by changes in cardiac structure or function, cardiomyopathy has a significant impact on the quality of life of patients. And the gut microbiota, as the “second genome”, can regulate cardiac function through the “gut-heart axis”, providing a new perspective for the prevention and treatment of cardiomyopathy. This article summarizes the types and quantitative characteristics of gut microbiota in patients with cardiomyopathy. From the perspective of direct effects and indirect effects of metabolites such as short chain fatty acids, trimethylamine oxide, and bile acids, the mechanisms by which gut microbiota affects cardiomyopathy are explained. And the therapeutic effects of various gut microbiota regulation methods, such as dietary regulation, traditional Chinese medicine regulation, probiotics and prebiotics regulation on cardiomyopathy are explored, in order to provide reference for scientific regulation of gut microbiota in the prevention and treatment of cardiomyopathy.
The incidence and mortality of esophageal cancer are high, with strong invasiveness and poor prognosis. In China, the number of morbidity and death accounts for about half of the world. The cause of the disease has not yet been clarified, and it is known to be related to many factors such as chronic damage to the upper digestive tract caused by poor diet and lifestyle, heredity and environment. With the continuous advancement of molecular biology technology, metagenomics and high-throughput sequencing began to be used as non-culture methods instead of traditional culture methods for micro-ecological analysis, and is becoming a research hotspot. Many studies have shown that the disturbance of upper digestive tract microecology may be one of the causes of esophageal cancer, which affects the occurrence and development of esophageal cancer through complex interactions with the body and various mechanisms. This paper reviews the research progress, which is of great significance to further clarify the value of upper gastrointestinal microecology in the pathogenesis, diagnosis and treatment of esophageal cancer.
Childhood obesity is a global public health problem that seriously affects the normal growth and development of children. In recent years, a large number of studies have pointed out that the intestinal microbiome is closely related to childhood obesity, and the treatment strategies targeting the intestinal microbiome have a certain improvement effect on childhood obesity. This article elaborates on the establishment and development of intestinal microbiome, intestinal microbiome characteristics, the mechanisms of intestinal microbiome involvement in the occurrence and development of childhood obesity, and potential intervention strategies, so as to provide more ideas for basic and clinical research on childhood obesity.
Rheumatoid arthritis (RA) is one of the most common immune-mediated diseases, and the interaction between the intestinal microbiota and the patient’s immune system may play a role in the occurrence and development of RA. Methotrexate (MTX), as a first-line drug for the treatment of RA, can be directly and indirectly influenced by intestinal microbiota and its enzyme products to affect the bioavailability, clinical efficacy, and toxicity of the drug. Therefore, it is crucial to understand the mechanism by which intestinal microbiota affects RA and the impact of intestinal microbiota on the efficacy of MTX. This article provides a review of the mechanisms by which intestinal microbiota may contribute to the pathogenesis of RA, as well as the role and impact of intestinal microbiota in MTX drug metabolism and treatment response.
ObjectiveTo investigate the effect of Roux-en-Y gastric bypass (RYGB) on the composition of intestinal microbiota among the biliopancreatic limb, the Roux limb, and the common channel in normal Sprague-Dawley (SD) rats. MethodsSixteen SD rats were randomly divided into sham surgery group (Sham group) and RYGB group, each group enrolled 8 rats. Rats in Sham group underwent sham surgery of end to end anastomosis in situ after cutting off the stomach and jejunum, and rats in RYGB group underwent RYGB. Then quantitative real-time PCR (RT-PCR) method was used to detect the expression of total bacteria, Bifidobacterium, Bacteroides, and Lactobacillus mRNA at biliopancreatic limb, the Roux limb, and the common channel. At last the comparison of mRNA in 4 kinds of bacteria was performed. ResultsCompared with Sham group, the weight of rats in RYGB group was lower at 8 weeks after surgery (P<0.01). RT-PCR results showed that, expression levels of total bacteria, Bifidobacterium, and Bacteroides mRNA at the Roux limb and the common channel in RYGB group were higher than corresponding site of rats in Sham group (P<0.05), but there was no significant difference at biliopancreatic limb between the 2 groups (P>0.05). Expression level of Lactobacillus mRNA at the Roux limb in RYGB group was higher than corresponding site of rats in Sham group (P<0.05), but there was no significant difference at biliopancreatic limb and the common channel between the 2 groups (P>0.05). ConclusionRYGB can significantly improve expression levels of the total bacteria, Bifidobacterium, and Bacteroides mRNA at Roux limb and the common channel, increase the level of Lactobacillus mRNA at Roux limb, while has no influence on biliopancreatic limb.
ObjectiveTo review the association of gut microbiota and postoperative gastrointestinal dysfunction (GID) in patients after abdominal surgery and to provide a new idea for the pathogenesis, prevention, and treatment of postoperative GID in patients after abdominal surgery.MethodThe related and latest literatures were reviewed by searching the literatures on “intestinal flora” “gut microbiota” “intestinal microbial population” “brain-gut axis” “gastrointestinal function” “gastric paralysis” “intestinal paralysis” and “ileus” from January 1, 2000 to April 2, 2021 in Chinese and English databases.ResultsGut microbiota diversity was closely related to postoperative GID symptoms in patients after abdominal surgery. Gut microbiota regulated gastrointestinal motility and mucosal barrier function by metabolizing food to produce metabolites such as 5-hydroxytryptamine, melatonin, short-chain fatty acid, succinic acid, lactic acid, and so on.ConclusionsThe imbalance of gut microbiota is closely related to postoperative GID in patients after abdominal surgery. However, the relevant bacterial metabolites that have been found are limited at present, and the relevant mechanism needs to be further investigated.
There is increasing evidence that microorganisms play a complex and important role in human health and disease, and that the in vivo microbiome can directly or indirectly affect the host’s immune system, endocrine system, and nervous system. Therefore, a relatively stable equilibrium between the host and the microbiome is crucial in human health. However, in the special pathophysiological state of the perioperative period, preoperative anxiety and sleep deprivation, anesthesia intervention and surgical injury, postoperative medication and complications may all have different effects on the microbial composition of various organs in the body, resulting in pathogenic microorganisms, and the balance between beneficial microorganisms is altered. This may affect patient the outcomes and prognosis in a direct or indirect manner. This paper will provide a systematic review of key studies to understand the impact of perioperative stress on the commensal microbiome, provide a fresh perspective on optimizing perioperative management strategies, and discuss possible potential interventions to restore microbiome-mediated steady state.
Diabetic retinopathy (DR) is one of the most serious microvascular complications of diabetes and a leading cause of visual impairment and blindness. In recent years, the role of intestinal and ocular microecology in DR has received increasing attention. Diabetic patients often present with dysbiosis of the intestinal flora, which is characterized by a decrease in anti-inflammatory bacteria, an increase in pro-inflammatory bacteria and a decrease in diversity, and may be involved in the progression of DR through inflammation and metabolic abnormalities. Localized flora changes in the eye may also be associated with DR. Animal experiments have shown that probiotics, prebiotics and fecal transplants have potential in improving flora, stabilizing blood glucose and attenuating retinopathy, but clinical applications need further validation. In the future, it is necessary to combine with multi-omics technology to study the function of bacterial flora in depth and explore novel therapeutic strategies, so as to provide new ideas for the prevention and treatment of DR.