Metalloporphyrin-modified semiconductors for solar fuel production

We report a direct one-step method to chemically graft metalloporphyrins to a visible-light-absorbing gallium phosphide semiconductor with the aim of constructing an integrated photocathode for light activating chemical transformations that include capturing, converting, and storing solar energy as fuels. Structural characterization of the hybrid assemblies is achieved using surface-sensitive spectroscopic methods, and functional performance for photoinduced hydrogen production is demonstrated via three-electrode electrochemical testing combined with photoproduct analysis using gas chromatography. Measurements of the total per geometric area porphyrin surface loadings using a cobalt-porphyrin based assembly indicate a turnover frequency ≥3.9 H2 molecules per site per second, representing the highest reported to date for a molecular-catalyst-modified semiconductor photoelectrode operating at the H+/H2 equilibrium potential under 1-sun illumination.

Cultivated Escherichia coli diversity in intestinal microbiota of Crohn's disease patients and healthy individuals: Whole genome data

Dysbiosis of the gut microbiota in inflammatory bowel disease (IBD) patients is of great interest. It has been reported that Crohn's disease (CD) is associated with a general decrease in microbial diversity [1]. Altered microbial composition and function in CD results in imbalance in host-bacteria interaction and increased immune stimulation [2]. It is shown that microbiota in CD is characterized by increased proportion of E. coli in human gut in contrast to healthy individuals [3]. However, the overall qualitative and quantitative diversity of E. coli strains in CD is not fully understood. Here, we present a dataset of whole-genome sequences of E. coli's.

Protective Effects of Probiotics on Cognitive and Motor Functions, Anxiety Level, Visceral Sensitivity, Oxidative Stress and Microbiota in Mice with Antibiotic-Induced Dysbiosis

Accumulating clinical and preclinical data indicate a prominent role of gut microbiota in regulation of physiological functions. The gut-brain axis imbalance due to gut dysbiosis is associated with a range of neurodegenerative diseases. Probiotics were suggested not only to restore intestinal dysbiosis but also modulate stress response and improve mood and anxiety symptoms. In this study, we assessed the effects of probiotic lactobacilli on behavioral reactions, the level of oxidative stress and microbiota content in mice administered to broad-spectrum antibiotics. Our study demonstrates that antibiotic treatment of adolescent mice for two weeks resulted in higher mortality and lower weight gain and induced significant changes in behavior including lower locomotor and exploratory activity, reduced muscle strength, visceral hypersensitivity, higher level of anxiety and impaired cognitive functions compared to the control group. These changes were accompanied by decreased diversity and total amount of bacteria, abundance of Proteobacteria and Verrucomicrobia phyla, and reduced Firmicutes/Bacteroides ratio in the gut microbiota. Moreover, a higher level of oxidative stress was found in brain and skeletal muscle tissues of mice treated with antibiotics. Oral administration of two Lactobacillus strains prevented the observed changes and improved not only microbiota content but also the behavioral alterations, suggesting a neuroprotective and antioxidant role of probiotics.

Repression of Staphylococcus aureus and Escherichia coli by Lactiplantibacillus plantarum Strain AG10 in Drosophila melanogaster In Vivo Model

Probiotic bacteria exhibiting antagonistic activities against pathogenic bacteria are widely considered as potential options for the prevention and treatment of various infectious diseases and represent potential substitutes of antibiotics. Here we show that the L. plantarum AG10 strain represses the growth of Staphylococcus aureus and Escherichia coli in vitro and diminishes their negative effects in vivo in a Drosophila melanogaster model of survival on embryonic (larvae) and pupa stages. In an agar drop diffusion test, L. plantarum AG10 exhibited antagonistic properties against Escherichia coli, Staphylococcus aureus, Serratia marcescens and Pseudomonas aeruginosa, and repressed the growth of E. coli and S. aureus during milk fermentation. In a Drosophila melanogaster model, L. plantarum AG10 alone did not provide any significant effect, either during the embryonic stage or during further development of the flies. Despite this, it was able to restore the viability of groups infected with either E. coli and S. aureus, almost to the level of non-treated control at all stages of development (larvae, pupa and adult). Moreover, in the presence of L. plantarum AG10, pathogens-induced mutation rates and recombination events reduced 1.5-2-fold. The genome of L. plantarum AG10 was sequenced and deposited at NCBI under the accession number PRJNA953814 and consists of annotated genome and raw sequence data. It consists of 109 contigs and is 3,479,919 bp in length with a GC content of 44.5%. The analysis of the genome has revealed considerably few putative virulence factors and three genes responsible for the biosynthesis of putative antimicrobial peptides, with one of them exhibiting a high probability of antimicrobial properties. Taken together, these data allow the suggestion that the L. plantarum AG10 strain is promising for use in both dairy production and probiotics as a preservative from foodborne infections.

Mechanic stimulation of the soles support zones as a countermeasure of the contractile properties decline under microgravity conditions

Decrease in muscle contractility is an inevitable consequence of exposure in microgravity. A wealth of currently accumulated facts is indicative of profound modifications in structure and function of the skeletal muscles in the absence of gravity. Investigations with humans during space flights of varying duration (L.I. Kakurin et al., 1971; I.B. Kozlovskaya et al., 1984, 1987, 1991;.), ground-based simulation studies (A.M. Genin et al., 1969; L.S. Grigorieva et al., 1983), and numerous experiments with animals (E.I. IIyina-Kakueva et al., 1979; O.M. Edgerton et al 1991; B.S. Shenkman et al., 1994) made it evident that removal of gravitational loading is fraught with significant reductions in the contractile properties of muscular fibers, especially noticeable in muscles-extensors. Results of ground-based simulation studies led to the hypothesis that changes in muscle contractility developing already after few days in microgravity conditions are consequent to reduction in support afferentation that plays an important role in initiation and maintenance of the activity of tonic motor units (A.V. Kirenskaya et al., 1986). In view of the above, an idea has been proposed to prevent losses in tonic muscles contractility by application of artificial support. Testing of this hypothesis was the theme of the present investigation.

Two-Year Study on the Intra-Individual Dynamics of Gut Microbiota and Short-Chain Fatty Acids Profiles in Healthy Adults

While the gut microbiome has been intensively investigated for more than twenty years already, its role in various disorders remains to be unraveled. At the same time, questions about what changes in the gut microbiota can be considered as normal or pathological and whether communities are able to recover after exposure to negative factors (diseases, medications, environmental factors) are still unclear. Here, we describe changes in the gut microbiota composition and the content of short-chain fatty acids in adult healthy volunteers (n = 15) over a 24 month-period. Intraindividual variability in gut microbial composition was 40%, whereas the short chain fatty acids profile remained relatively stable (2-year variability 20%, inter-individual 26%). The changes tend to accumulate over time. Nevertheless, both short-term and long-term changes in the gut microbiome composition were significantly smaller within individuals than interindividual differences (two-year interindividual variability was 75%). Seasonal changes in gut microbiota were found more often in autumn and spring involving the content of minor representatives (less than 1.5% of the community in average) in the phyla Actinobacteriota, Firmicutes and Proteobacteria.

Association between Taxonomic Composition of Gut Microbiota and Host Single Nucleotide Polymorphisms in Crohn's Disease Patients from Russia

Crohn's disease (CD) is a chronic relapsing inflammatory bowel disease of unknown etiology. Genetic predisposition and dysbiotic gut microbiota are important factors in the pathogenesis of CD. In this study, we analyzed the taxonomic composition of the gut microbiota and genotypes of 24 single nucleotide polymorphisms (SNP) associated with the risk of CD. The studied cohorts included 96 CD patients and 24 healthy volunteers from Russia. Statistically significant differences were found in the allele frequencies for 8 SNPs and taxonomic composition of the gut microbiota in CD patients compared with controls. In addition, two types of gut microbiota communities were identified in CD patients. The main distinguishing driver of bacterial families for the first community type are Bacteroidaceae and unclassified members of the Clostridiales order, and the second type is characterized by increased abundance of Streptococcaceae and Enterobacteriaceae. Differences in the allele frequencies of the rs9858542 (BSN), rs3816769 (STAT3), and rs1793004 (NELL1) were also found between groups of CD patients with different types of microbiota communities. These findings confirm the complex multifactorial nature of CD.

Butyric Acid Supplementation Reduces Changes in the Taxonomic and Functional Composition of Gut Microbiota Caused by H. pylori Eradication Therapy

H. pylori eradication therapy leads to significant changes in the gut microbiome, including influence on the gut microbiome's functional potential. Probiotics are one of the most studied potential methods for reducing the microbiota-related consequences of antibiotics. However, the beneficial effects of probiotics are still under discussion. In addition, there are some concerns about the safety of probiotics, emphasizing the need for research of other therapeutic interventions. The aim of our study was to evaluate the influence of butyric acid+inulin supplements on gut microbiota changes (the gut microbiota composition, abundance of metabolic pathways, and gut resistome) caused by H. pylori eradication therapy.

MATERIALS AND METHODS

Twenty two H. pylori-positive patients, aged 19 to 64 years, were enrolled in the study and randomized into two treatment groups, as follows: (1) ECAB-14 (n = 11), with esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, per os, for 14 days, and (2), ECAB-Z-14 (n = 11), with esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, along with butyric acid+inulin (Zacofalk), two tablets daily, each containing 250 mg of butyric acid, and 250 mg of inulin, per os, for 14 days. Fecal samples were collected from each subject prior to eradication therapy (time point I), after the end of eradication therapy (time point II), and a month after the end of eradication therapy (time point III). The total DNA from the fecal samples was isolated for whole genome sequencing using the Illumina NextSeq 500 platform. Qualitative and quantitative changes in gut microbiota were assessed, including alpha and beta diversity, functional potential and antibiotic resistance gene profiling.

RESULTS

Gut microbiota alpha diversity significantly decreased compared with the baseline immediately after eradication therapy in both treatment groups (ECAB-14 and ECAB-Z-14). This diversity reached its baseline in the ECAB-Z-14 treatment group a month after the end of eradication therapy. However, in the ECAB-14 treatment arm, a reduction in the Shannon index was observed up to a month after the end of H. pylori eradication therapy. Fewer alterations in the gut microbiota functional potential were observed in the ECAB-Z-14 treatment group. The abundance of genes responsible for the metabolic pathway associated with butyrate production decreased only in the ECAB-14 treatment group. The prevalence of antibiotic-resistant genes in the gut microbiota increased significantly in both treatment groups by the end of treatment. However, more severe alterations were noted in the ECAB-14 treatment group.

CONCLUSIONS

H. pylori eradication therapy leads to taxonomic changes, a reduction in the alpha diversity index, and alterations in the functional potential of the gut microbiota and gut resistome. Taking butyric acid+inulin supplements during H. pylori eradication therapy could help maintain the gut microbiota in its initial state and facilitate its recovery after H. pylori eradication.

Whole Genome Sequencing of the Novel Probiotic Strain Lactiplantibacillus plantarum FCa3L

Lactiplantibacillus plantarum is best known for its significant adaptive potential and ability to colonize different ecological niches. Different strains of L. plantarum are widely used as probiotics. To characterize the probiotic potential of the novel L. plantarum FCa3L strain isolated from fermented cabbage, we sequenced its whole genome using the Illumina MiSeq platform. This bacterial isolate had a circular chromosome of 3,365,929 bp with 44.3% GC content and a cyclic phage phiX174 of 5386 bp with 44.7% GC content. The results of in vitro studies showed that FCa3L was comparable with the reference probiotic strain L. plantarum 8PA3 in terms of acid and bile tolerance, adhesiveness, H₂O₂ production, and acidification rate. The strain 8PA3 possessed higher antioxidant activity, while FCa3L demonstrated superior antibacterial properties. The antibiotic resistance of FCa3L was more relevant to the probiotic strain than that of 8PA3, although a number of silent antibiotic resistance genes were identified in its genome. Genomic evidence to support adhesive and antibacterial properties, biosynthesis of bioactive metabolites, and safety of FCa3L was also presented. Thus, this study confirmed the safety and probiotic properties of L. plantarum FCa3L via complete genome and phenotype analysis, suggesting its potential as a probiotic, although further in vivo investigations are still necessary.