In the February 24th issue of The Zealotific Daily, we deciphered 9 articles focusing on: lung flora, interbacterial interactions, probiotics, schizophrenia, intestinal brain axis, group sensing, antibiotics, drug-resistant bacteria, infant microbiota
Nature: Lung flora affects neuroinflammation of the brain
Nature——[49.962]
(1) In the rat model, the susceptibility of rats to autoimmune encephalomyelitis (EAE) can be significantly affected by direct injection of antibiotics into the lungs to change the lung flora; (2) neomycin-induced changes in the lung flora mainly enhance rat resistance to EAE by affecting microglia (rather than T cells); (3) mechanically, the neomycin treatment dilates the Bacteroides phylum lipopolysaccharide (LPS) in the lung flora, which makes the immune status of microglia in the brain shift to a type I interferon response. (4) Administering polymyxin B to neutralize LPS in the lungs can exacerbate EAE in rats, while supplementation with specific LPS or its producing bacteria can resist EAE.
【Editor-in-Chief's Comments】
Multiple sclerosis (MS) is an autoimmune disease of the central nervous system. Many studies have revealed the effects of the gut microbiota on MS, and the latest study published by Nature is the first to find that the lung flora can also affect susceptibility to MS and reveal the immune mechanisms behind it. (@User 970937765)
【Original information】
The lung microbiome regulates brain autoimmunity
2022-02-23, doi: 10.1038/s41586-022-04427-4
Nature: Bacterial toxins that promote bowel cancer can detonate "time bombs" in other intestinal bacteria
(1) Colibactin, a genotoxin produced by a specific bacterium, can cause extensive changes in the composition of the intestinal flora; (2) this effect does not stem from direct inhibition of bacterial growth, but activates the prophages within the bacteria by causing the bacterial DNA damage response, causing phage replication and leading to bacterial lysis; (3) Colibactin bacteria are observed in the human body and intestine-related various phage-bacterial systems, as well as in the mouse fecal flora, the role of colibactin bacteria in inducing protophages is observed; (4) The identification of homologues of Colibactin-resistant ClbS in a variety of bacteria that do not produce colibactin can help bacteria resist colibactin.
The bacterial toxin colibactin produced by some bacteria in the intestinal flora (such as pks + E. coli) is a chemically unstable small molecule gene toxin, and its genotoxicity to host cells can increase the risk of colorectal cancer in the host. The effects of colibactin on other microorganisms in the microbiota are currently poorly studied. Nature recently published the research of Emily P. Balskus' team at Harvard University, and found that colibactin can target the bacteria containing prophages around it, awakening the sleeping prophages inside the bacteria and causing bacterial lysis. These findings illustrate the underlying mechanisms by which colibactin affects the microbiota, as well as the relationship between bacterial products and phage behavior. The authors believe that the reason why bacteria evolved this gene toxin may be mainly to inhibit other bacteria, not to poison the host, from this point of view, the pro-cancer effect of colibactin may belong to the "accidental injury" of the host. (@User 970937765)
The bacterial toxin colibactin triggers prophage induction
2022-02-23, doi: 10.1038/s41586-022-04444-3
Probiotic extracellular polysaccharides may enhance tumor immunotherapy
Cancer Discovery——[39.397]
(1) Oral EPS-R1 in mice can induce CCR6+ CD8+ T cells in Pyle's pooled lymph nodes; (2) CCR6 gene expression is associated with better prognosis in patients in cancers expressing CCL20; (3) in mice, EPS-R1 enhances the efficacy of CTLA-4 monoclonal antibodies and PD-1 monoclonal antibodies on CCL20-expressing tumors by increasing the infiltration of CCR6+ CD8+ T cells and inducing IFN-γ production to maintain T cell function, thereby enhancing the efficacy of CTLA-4 monoclonal antibodies and PD-1 monoclonal antibodies on tumors expressing CCL20, and this effect is not dependent on the microflora ;(4) Mechanism, the phosphorylated structure of EPS-R1 can induce CCR6+ CD8+ T cells by acting on hemolytic phosphatidylic acid receptors on CD8+ T cells.
A new study published in Cancer Discovery found that extracellular polysaccharides (EPS-R1) produced by the Bulgarian subspecies of Lactobacillus dei(Lactobacillus) OLL1073R-1 can enhance the efficacy of immune checkpoint inhibitors in mouse tumors expressing CCL20 by inducing CCR6+ CD8+ T cells. In cancers that express CCL20, CCR6 expression is associated with a better prognosis for patients. （@aluba）
Dietary Lactobacillus-derived exopolysaccharide enhances immune checkpoint blockade therapy
2022-02-17, doi: 10.1158/2159-8290.CD-21-0929
Zhu Feng + Ma Xiancang: Microbiota-immune interaction disorder in schizophrenia
Molecular Psychiatry——[15.992]
(1) Compared with healthy controls, the cytokine response pattern of PBMCs to bacteria, fungi and microbiota ligands in patients with schizophrenia was different, and the cytokines produced under the stimulation of linacyl dipeptide (MDP) decreased; (2) in PBMC of patients with schizophrenia, the antiviral and inflammatory response pathways were widely inhibited, and the chemokines/cytokine-receptor interaction networks between various immune cell subsets after MDP stimulation were impaired; (3) serum MDP levels in patients with schizophrenia were elevated and correlated with the course of the disease. (4) MDP pretreatment can alter the functional response of PBMC of healthy controls to MDP re-stimulation.
A new study by Zhu Feng, Ma Xiancang and his team at the First Affiliated Hospital of Xi'an Jiaotong University in Molecular Psychiatry found that compared with healthy controls, the immune response of PBMCs to bacteria and fungi in patients with schizophrenia was impaired, and bacterial translocations may be associated with disease progression. （@aluba）
Systems biological assessment of altered cytokine responses to bacteria and fungi reveals impaired immune functionality in schizophrenia
2021-11-02, doi: 10.1038/s41380-021-01362-0
Ma Xiancang + Zhu Feng: The association between long-term intestinal dysbiosis and post-traumatic stress symptoms in anti-epidemic medical staff
Journal of Affective Disorders——[4.839]
(1) Long-term changes in the intestinal flora of frontline medical workers (FHW) and their relationship with psychological stress were analyzed by 16S rRNA gene sequencing; (2) anti-epidemic stress caused by severe depression, anxiety and stress in FHW, disturbing the intestinal flora, and intestinal dysregulation lasted for at least half a year; (3) during the half-year follow-up period, the trajectory of different bacteria was different; (4) Bacillus p. perciscenum and Eubacterium perceptus with anti-inflammatory effects were clearly associated with stress symptoms; (5) A low-abundance eugenia hawthorni and a high-abundance Bacteroides essiella at baseline (after the end of the first-line fight against covid-19) can predict the recurrence of FHW post-traumatic stress symptoms.
Ma Xiancang and Zhu Feng of the First Affiliated Hospital of Xi'an Jiaotong University, as co-corresponding authors, published a study in the Journal of Affective Disorders, revealing that among medical staff on the frontline of the new crown epidemic, long-term intestinal microbiota disorders caused by anti-epidemic stress and the symptoms of post-traumatic stress associated with it have brought new enlightenment for understanding the characteristics of the intestinal flora of stress disorder and finding potential intervention targets. (@User 970937765)
Stressful events induce long-term gut microbiota dysbiosis and associated post-traumatic stress symptoms in healthcare workers fighting against COVID-19
2022-02-12, doi: 10.1016/j.jad.2022.02.024
Central Agricultural University: Molecular Mechanisms of Population Sensing Signaling Molecules Damaging Host Cells (Review)
Gut Microbes——[10.245]
(1) Quorum sensing molecules not only control the behavior of the microbial community, but also regulate the physiological state of host cells; (2) Gram-negative bacteria Quichthys sensing signaling molecules (AHL) have cell type-specific effects on host cell function (such as apoptosis and immunity); (3) where lipid rafts, PPAR-γ, PON2, and TNFR1 may be key molecules for AHL to damage host cells; (4) AHL damages the intestinal health of animals of different species by interfering with intestinal epithelial cells and goblet cells; (5) Animal tests are urgently needed to track the source of AHL and analyze the trajectory of AHL between the intestinal lumen and epithelial cells, so as to better analyze the mechanisms by which AHL affects the health of the host intestine.
In recent decades, people's understanding of microbial population sensing (QS) has greatly improved, and the interaction between microbial population sensing molecules (QSSM) and mammalian host cells has also been deeply studied. Gut Microbes published a review article by Shiyu Tao and his team from Huazhong Agricultural University, which systematically summarizes the effects of AHL (a QSSM produced by Gram-negative bacteria) on host cells and its potential mechanisms. The relationship between AHL and intestinal diseases was reviewed and confirmed that 3-oxo-C12-HSL is a type of AHL that plays a key role in the development of metabolic diseases in animals. In addition, the article also proposes the shortcomings of current research and the direction of future research. Recommended reading! (@User 975688480)
Impact of quorum sensing signaling molecules in gram-negative bacteria on host cells: current understanding and future perspectives
2022-02-19, doi: 10.1080/19490976.2022.2039048
Rectal colonization of drug-resistant bacteria increases the risk of colonization strain infection in patients with critical liver cirrhosis
Journal of Hepatology——[25.083]
(1) Prospective cohort studies were conducted in 486 critically ill patients (129 cases of cirrhosis, 357 cases of non-cirrhosis) and retrospective cohort studies were conducted in 421 patients with cirrhosis; (2) in the prospective cohort, the colonization rate of rectal multidrug-resistant bacteria was higher during hospitalization (rather than during the ICU) in patients with cirrhosis, and the most common multidrug-resistant bacteria were enterobacterium order with ultra-broad-spectrum β lactamase; (3) rectal colonization of multi-resistant bacteria was also prevalent in the retrospective cohort, The most common multidrug-resistant bacteria are Vancomycin-resistant Enterococcus, and (4) Rectal colonization of multidrug-resistant bacteria was significantly associated with an increased risk of multidrug-resistant bacteria infection in both cohorts.
The results of a cohort study published in the Journal of Hepatology found in both a prospective cohort and a retrospective cohort that rectal colonization of multidrug-resistant bacteria is prevalent in critically ill patients with cirrhosis and is associated with an increased risk of multidrug-resistant infection. （@aluba）
Rectal colonization by resistant bacteria increases the risk of infection by the colonizing strain in critically ill patients with cirrhosis
2022-01-21, doi: 10.1016/j.jhep.2021.12.042
Nature Sub-Journal: How Antibiotics Affect Infants' Gut Microbiota and Drug-Resistant Groups
Nature Communications——[14.919]
(1) 147 children with sEONS were randomly divided into 3 groups, each treated with 3 different antibiotic combinations, and 80 healthy infants who did not use antibiotics were included as controls; (2) after antibiotic treatment, the intestinal flora composition and antimicrobial resistance gene spectrum of infants changed significantly and returned to normal after 12 months; (3) compared with healthy infants, the abundance of Bifidobacterium genus decreased in the intestinal flora of infants after antibiotic treatment, and the abundance of Klebsiella and Enterococcus spp., (4) amoxicillin + Cefotaxime had the greatest effect on community composition and antimicrobial resistance gene profile, while penicillin + gentamicin had the least effect.
A new study published in Nature Communications compared the effects of different antibiotic combinations on infantile gut flora and drug-resistant groups in 147 children with early-onset neonatal sepsis (sEONS) and 80 healthy infants without antibiotics. （@aluba）
Effects of early-life antibiotics on the developing infant gut microbiome and resistome: a randomized trial
2022-02-16, doi: 10.1038/s41467-022-28525-z
Hong Kong Polytechnic University: Hospital-derived respirable resistance genes and host communities, clinical associations, and environmental risks
Microbiome——[14.65]
(1) Metagenomic sequencing, bioinformatics assembly and binning, and related environmental metadata were extensively compared in this study; (2) it was revealed that the antibiotic resistance group was significantly associated with bacterial communities under different seasonal conditions; (3) the antibiotic resistance group was mainly affected by ambient air temperature and humidity, and its abundance content was significantly correlated with the number of drug-resistant infection cases in hospitals; (4) this potential medical source association, or led to the enrichment of human pathogenic resistance bacteria such as Staphylococcus aureus and Diphtheriae bacillus in the exhaust of out-of-hospital exhaust bacteria; (5) Its inhalation exposure is significantly higher than (about 10 times) of drinking water, with greater environmental health risks.
In this paper, Li Xiangdong's team at the Hong Kong Polytechnic University conducted an in-depth study of the host community, clinical significance, and health risks of the fine particulate matter (PM2.5) loaded in the external exhaust port of a large urban center hospital in mainland China, and found that the abundance of ARGs in the medical source PM2.5 was 2–5 times that of the urban ambient air, and contained a large number of potential human pathogenic ARGs host bacteria, including Staphylococcus aureus and Bacillus diphtheriae, which may cause 40 ~ a single day for the population Inhalation exposure flux of resistant pathogenic bacteria at 60 genome copies/day carries environmental health risks that cannot be ignored. The results of this study reveal the mechanism of respirable ARG airborne migration and transmission, clarify the risk of resistance to medical sources, and provide a scientific basis for its management. (@User 954652200)
Inhalable antibiotic resistomes emitted from hospitals: metagenomic insights into bacterial hosts, clinical relevance, and environmental risks
2022-01-27, doi: 10.1186/s40168-021-01197-5
Thanks to the creators of this issue of the daily: user 970937765, aluba, user 937941148, user 975688480, user 970955016, user 954652200
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