Intestinal microbiota: a new perspective on delaying aging?

The global aging situation is severe, and the medical pressures associated with aging issues should not be underestimated. The need and feasibility of studying aging and intervening in aging have been confirmed. Aging is a complex natural physiological progression, which involves the irreversible deterioration of body cells, tissues, and organs with age, leading to enhanced risk of disease and ultimately death. The intestinal microbiota has a significant role in sustaining host dynamic balance, and the study of bidirectional communication networks such as the brain–gut axis provides important directions for human disease research. Moreover, the intestinal microbiota is intimately linked to aging. This review describes the intestinal microbiota changes in human aging and analyzes the causal controversy between gut microbiota changes and aging, which are believed to be mutually causal, mutually reinforcing, and inextricably linked. Finally, from an anti-aging perspective, this study summarizes how to achieve delayed aging by targeting the intestinal microbiota. Accordingly, the study aims to provide guidance for further research on the intestinal microbiota and aging

Lactic acid bacteria with a strong antioxidant function isolated from “Jiangshui,” pickles, and feces

Excessive free radicals and iron death lead to oxidative damage, which is one of the main causes of aging and diseases. In this field of antioxidation, developing new, safe, and efficient antioxidants is the main research focus. Lactic acid bacteria (LAB) are natural antioxidants with good antioxidant activity and can regulate gastrointestinal microecological balance and immunity. In this study, 15 LAB strains from fermented foods (“Jiangshui” and pickles) or feces were evaluated in terms of their antioxidant attributes. Strains with strong antioxidant capacity were preliminarily screened by the following tests: 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical, superoxide anion radical scavenging capacity; ferrous ion chelating assay; hydrogen peroxide tolerance capacity. Then, the adhesion of the screened strains to the intestinal tract was examined using hydrophobic and auto-aggregation tests. The safety of the strains was analyzed based on their minimum inhibitory concentration and hemolysis, and 16S rRNA was used for molecular biological identification. Antimicrobial activity tests showed them probiotic function. The cell-free supernatant of selected strains were used to explore the protective effect against oxidative damage cells. The scavenging rate of DPPH, hydroxyl radicals, and ferrous ion-chelating of 15 strains ranged from 28.81–82.75%, 6.54–68.52%, and 9.46–17.92%, respectively, the scavenging superoxide anion scavenging activity all exceeded 10%. According to all the antioxidant-related tests, strains possessing high antioxidant activities J2-4, J2-5, J2-9, YP-1, and W-4 were screened, these five strains demonstrated tolerance to 2 mM hydrogen peroxide. J2-4, J2-5, and J2-9 were Lactobacillus fermentans and γ-hemolytic (non-hemolytic). YP-1 and W-4 were Lactobacillus paracasei and α-hemolytic (grass-green hemolytic). Although L. paracasei has been proven as a safe probiotic without hemolytic characteristics, the hemolytic characteristics of YP-1 and W-4 should be further studied. Due to the weak hydrophobicity and antimicrobial activity of J2-4, finally, we selected J2-5, J2-9 for cell experiment, J2-5 and J2-9 showed an excellent ability that resistant to oxidative damage by increasing SOD, CAT, T-AOC activity of 293T cells. Therefore, J2-5, and J2-9 strains from fermented foods “Jiangshui” could be used as potential antioxidants for functional food, health care, and skincare

Regio-selective Reduction of Oxysophoridine by Microorganism Isolated from Soil

Oxysophoridine (OSR), an alkaloid extracted from a traditional Chinese medicine, attracted more and more attention because of remarkable biological activities. Biocatalysis of OSR by 86 stains including soil microbes and endophytic fungi were investigated. Incubation of OSR with soil bacteria T003 identified as Escherichia coli could lead to only one reductive product with highly regio-selectivity. The structural elucidations of transformation product were achieved mainly by the NMR spectroscopic methods and references. Effect of pH, substrate concentration, conversion time and strain concentration was studied, the optimization of reaction was analyzed by LC-MS. The production of sophoridine (SR) from OSR was highest at pH 7.0, 36 h of incubation and in presence of 625 mu g/mL substrate concentration, 50 mu L/mL strain concentration respectively. Biocatalysis was considered the alternatives to preparation of sophoridine with green and sustainable synthetic processes except for less time-consuming and more environmentally friendly

The function of small RNA in Pseudomonas aeruginosa

Pseudomonas aeruginosa, the main conditional pathogen causing nosocomial infection, is a gram-negative bacterium with the largest genome among the known bacteria. The main reasons why Pseudomonas aeruginosa is prone to drug-resistant strains in clinic are: the drug-resistant genes in its genome and the drug resistance easily induced by single antibiotic treatment. With the development of high-throughput sequencing technology and bioinformatics, the functions of various small RNAs (sRNA) in Pseudomonas aeruginosa are being revealed. Different sRNAs regulate gene expression by binding to protein or mRNA to play an important role in the complex regulatory network. In this article, first, the importance and biological functions of different sRNAs in Pseudomonas aeruginosa are explored, and then the evidence and possibilities that sRNAs served as drug therapeutic targets are discussed, which may introduce new directions to develop novel disease treatment strategies

A dominant variant in apoptosis-related gene XKR8 is relevant to hereditary auditory neuropathy

Abstract Background Auditory neuropathy is an unusual type of hearing loss. At least 40% of patients with this disease have underlying genetic causes. However, in many hereditary auditory neuropathy cases, etiology remains undetermined. Methods We collected data and blood samples from a four-generation Chinese family. After excluding relevant variants in known deafness-related genes, exome sequencing was conducted. Candidate genes were verified by pedigree segregation, transcript/protein expression in the mouse cochlea, and plasmid expression studies in HEK 293T cells. Moreover, a mutant mouse model was generated and underwent hearing evaluations; protein localization in the inner ear was also assessed. Results The clinical features of the family were diagnosed as auditory neuropathy. A novel variant c.710G > A (p.W237X) in apoptosis-related gene XKR8 was identified. Genotyping of 16 family members confirmed the segregation of this variant with the deafness phenotype. Both XKR8 mRNA and XKR8 protein were expressed in the mouse inner ear, predominantly in regions of spiral ganglion neurons; Moreover, this nonsense variant impaired the surface localization of XKR8 in cells. Transgenic mutant mice exhibited late-onset auditory neuropathy, and their altered XKR8 protein localization in the inner ear confirmed the damaging effects of this variant. Conclusions We identified a variant in the XKR8 gene that is relevant to auditory neuropathy. The essential role of XKR8 in inner ear development and neural homeostasis should be explored

Molecular Genetic Characterization of an Anthrabenzoxocinones Gene Cluster in Streptomyces Sp. FJS31-2 for the Biosynthesis of BE-24566B and Zunyimycin Ale

Genome mining is an effective tool used to discover novel natural products from actinomycetes. Genome sequence analysis of Streptomyces sp. FJS31-2 revealed the presence of one putative type II polyketide gene cluster (ABX), which may correspond to type II polyketide products including BE-24566B and its chloro-derivatives. The addition of natural humus acid successfully activated the biosynthsis of the abx gene cluster. BE-24566B and its chloro-derivatives, named zunyimycin A, were also detected. The targeted deletion of the polyketide skeleton synthesis genes such as abxp, abxk, and abxs was performed in the wild strain to identify the gene cluster for BE-24566B biosynthesis

Additional file 1 of A dominant variant in apoptosis-related gene XKR8 is relevant to hereditary auditory neuropathy

Additional file 1. Table S1

Zunyimycins B and C, New Chloroanthrabenzoxocinones Antibiotics against Methicillin-Resistant Staphylococcus aureus and Enterococci from Streptomyces sp. FJS31-2

This study performed an optimization of the fermentation conditions to activate the expression of the zunyimycin family biosynthesis genes of the zunyimycin-producing streptomycetes strain Streptomyces sp. FJS31-2. Bioassay-guided isolation and purification by varied chromatographic methods yielded two new compounds of the zunyimycin derivatives, namely, 31-2-7 and 31-2-8, accompanied with three known anthrabenzoxocinones family members of zunyimycin A, BE24566B, and chloroanthrabenzoxocinone. Their structures were elucidated by NMR, HRESIMS, IR, UV, and CD. Results showed that these two compounds were structurally similar to the previously reported compound zunyimycin A but differed in positions and number of chlorine atom substitution. The two novel compounds were called zunyimycins B and C. Antibacterial activity assay indicated that zunyimycin C showed a good inhibitory effect on the methicillin-resistant Staphylococcus aureus and Enterococci