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BackgroundThe mucosa-associated gut microbiota directly modulates epithelial and mucosal function. In this study, we investigated the mucosa-associated microbial community in patients with inflammatory bowel disease (IBD), using endoscopic brush samples.MethodsA total of 174 mucus samples from 43 patients with ulcerative colitis (UC), 26 with Crohn’s disease (CD) and 14 non-IBD controls were obtained by gentle brushing of mucosal surfaces using endoscopic cytology brushes. The gut microbiome was analyzed using 16S rRNA gene sequencing.ResultsThere were no significant differences in microbial structure among different anatomical sites (the ileum, cecum and sigmoid colon) within individuals. There was, however, a significant difference in microbial structure between CD, UC and non-IBD controls. The difference between CD and non-IBD controls was more marked than that between UC patients and non-IBD controls. α-Diversity was significantly lower in UC and CD patients than non-IBD controls. When comparing CD patients with non-IBD controls, the phylum Proteobacteria was significantly increased and the phyla Firmicutes and Bacteroidetes were significantly reduced. These included a significant increase in the genera Escherichia, Ruminococcus (R. gnavus), Cetobacterium, Actinobacillus and Enterococcus, and a significant decrease in the genera Faecalibacterium, Coprococcus, Prevotella and Roseburia. Comparisons between CD and UC patients revealed a greater abundance of the genera Escherichia, Ruminococcus (R. gnavus), Clostridium, Cetobacterium, Peptostreptococcus in CD patients, and the genera Faecalibacterium, Blautia, Bifidobacterium, Roseburia and Citrobacter in UC patients.ConclusionsMucosa-associated dysbiosis was identified in IBD patients. CD and UC may be distinguishable from the mucosa-associated microbial community structure.

Recent studies have highlighted the impact of disrupted maternal gut microbiota on the colonization of offspring gut microbiota, with implications for offspring developmental trajectories. The extent to which offspring inherit the characteristics of altered maternal gut microbiota remains elusive. In this study, we employed a mouse model where maternal gut microbiota disruption was induced using non-absorbable antibiotics. Systematic chronological analyses of dam fecal samples, offspring luminal content, and offspring gut tissue samples revealed a notable congruence between offspring gut microbiota profiles and those of the perturbed maternal gut microbiota, highlighting the profound influence of maternal microbiota on early-life colonization of offspring gut microbiota. Nonetheless, certain dominant bacterial genera in maternal microbiota did not transfer to the offspring, indicating a bacterial taxonomy-dependent mechanism in the inheritance of maternal gut microbiota. Our results embody the vertical transmission dynamics of disrupted maternal gut microbiota in an animal model, where the gut microbiota of an offspring closely mirrors the gut microbiota of its mother.

An optically active π-stacked molecule was synthesized incorporating planar chiral [2.2]paracyclophane and o -carborane units to impart circularly polarized luminescence and aggregation-induced emission properties to the molecule. The molecule exhibited a strong emission from the aggregated state in a mixed solvent system (H 2 O/THF) and the solid state in the PMMA matrix. In the aggregated state, weak circularly polarized luminescence was observed owing to the random intermolecular orientation. On the other hand, the circularly polarized luminescence was clearly observed in the PMMA film containing 1 wt% molecule. Theoretical studies using time-dependent density functional theory reproduced the molecule’s circular dichroism and circularly polarized luminescence properties.

Cancer cachexia and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer‐related muscle wasting and its mechanism using a colon‐26 murine cachexia model. Compared with a fiber‐free (FF) diet, PHGG contained fiber‐rich (FR) diet–attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle‐specific ubiquitin ligases Atrogin‐1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight‐junction markers were partially reduced in both FR and FF diet–fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24‐7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide‐binding protein (LBP) and IL‐6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin‐proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. Our results suggest that dietary fiber alters the gut microbiota and restores the gut barrier function in cachectic mice and that these modifications induce a systemic anti‐inflammatory effect, thereby attenuating muscle wasting.

Background: Gut dysbiosis associated with the use of proton-pump inhibitors (PPIs) has been found to lead to the occurrence of infectious and inflammatory adverse events. A longitudinal observational cohort study has demonstrated the heightened risk of death associated with PPI use. Summary: We evaluated meta-analyses to determine the association between PPI use and infectious and inflammatory diseases. Meta-analyses showed that PPI use is a potential risk for the development of enteric infections caused by Clostridium difficile, as well as small intestinal bacterial overgrowth, spontaneous bacterial peritonitis, community-acquired pneumonia, hepatic encephalopathy, and adverse outcomes in inflammatory bowel disease. We also examined changes in the composition and function of the gut microbiota with the use of PPIs. PPI use significantly increased the presence of Streptococcaceae and Enterococcaceae, which are risk factors for C. difficile infection, and decreased that of Faecalibacterium, a commensal anti-inflammatory microorganism. Key Message: High-throughput, microbial 16S rRNA gene sequencing has allowed us to investigate the association between the gut microbiome and PPI use. Future prospective comparison studies are necessary to confirm this association, and to develop new strategies to prevent complications of PPI use

BackgroundHuman gut microbiota is involved in host health and disease development. Investigations of age-related and sex-related alterations in gut microbiota are limited, and the association between stool consistency and gut microbiota has not been fully investigated. We investigated gut microbiota differences related to age, sex, and stool consistency in healthy Japanese subjects.MethodsTwo-hundred and seventy-seven healthy Japanese subjects aged 20–89 years were enrolled. Fecal samples were obtained to analyze the gut microbiome. We evaluated the association between stool consistency [Bristol stool scale (BSS)] and gut microbiota.ResultsAlthough there were significant differences in the microbial structure between males and females, the α-diversity of gut microbiota showed no difference between males and females or among age groups. There were significant increases in genera Prevotella, Megamonas, Fusobacterium, and Megasphaera and Bifidobacterium, Ruminococcus, and Akkermansia in males and females, respectively. The ratio of hard stools (BSS types 1 and 2) was higher in females; the ratio of loose stools (BSS type 6) was higher in males. No younger male had BSS type 1 or type 2. Fusobacterium in males was significantly higher in the loose consistency group, and Oscillospira was significantly higher in the hard consistency group in males; Campylobacter, SMB53, and Turicibacter were significantly higher in the hard consistency group in females.ConclusionsSeveral changes in gut microbiota were associated with age and sex. Stool consistency and gut microbiota associations emphasized the importance of stool consistency assessments to understand intestinal function.

The heat resistance of carbon fiber-reinforced ultra-high-temperature ceramic matrix composites (C/UHTCMCs) was characterized by arc-wind tunnel testing with heat fluxes of 2, 4.54, and 6.68 MW/m2. C/UHTCMCs were fabricated via Zr-Ti binary alloy (Zr-20at%Ti, Zr-64at%Ti, Zr-80at%Ti) melt infiltration. The thickness and weight changes of the specimen were dependent on the composition of the infiltrated Zr-Ti alloy. Microstructural and thermodynamic analyses revealed that formed oxides on the surface of composites are composed of ZrO2 solid solution, ZrTiO4 solid solution, and TiO2 solid solution. The composition of oxides also depends on the composition of infiltrated alloys. The difference originates from the formation and composition of oxide scales and the dynamic pressure. Especially, formation of liquid oxides accelerates the recession of composites because liquid oxides are disappeared from the surface owing to the dynamic pressure during arc-wind tunnel testing. To withstand aerodynamic heating above 2000 °C, formation of a solid (and liquid) oxide on the exposed surface is required to reduce recession.

Background/Objectives: Aging is characterized by progressive functional decline associated with alterations in gut microbiota, epithelial barrier dysfunction, and cellular senescence. Although quercetin has been proposed as a potential anti-aging compound, its clinical application is limited by poor bioavailability. In this study, we investigated whether enhancing quercetin bioavailability using EubioQuercetin (EQN) modulates aging-related phenotypes through the gut microbiota–intestinal barrier axis. Methods: Male C57BL/6J mice were treated with EQN or conventional quercetin (CQN) for 12 weeks. External aging phenotypes were assessed using a composite aging score based on hair glossiness, hair loss, and the presence of white hair. Gut microbiota composition was analyzed via 16S rRNA sequencing with centered log-ratio transformation, and intestinal gene expression was assessed by quantitative reverse transcription-polymerase chain reaction. Results: EQN significantly reduced the aging score compared with the control group (median 4.5 vs. 8, p < 0.01), while CQN also showed a moderate reduction. Microbiota analysis identified taxa positively associated with aging (Lactobacillus, Romboutsia, Desulfovibrio, and Lachnoclostridium) and negatively associated taxa (Akkermansia and Christensenellaceae). EQN suppressed aging-associated taxa and partially increased taxa linked to a healthier microbiota profile. At the intestinal level, EQN downregulated senescence-associated genes (p21, PCNA, and Lgr5) and upregulated the tight junction gene claudin-1. In contrast, systemic inflammatory markers and short-chain fatty acids were not significantly associated with the aging score. Conclusions: These findings indicate that enhancing quercetin bioavailability attenuates externally assessed aging phenotypes in aged mice and is associated with coordinated changes in gut microbiota and intestinal gene expression. Modulation of the gut microbiota–intestinal barrier axis may represent a potential mechanism underlying these effects.

In Brillouin optical correlation-domain reflectometry (BOCDR), sinusoidal modulation is applied to the output frequency of a light source, with spatial resolution inversely related to the modulation amplitude. We have developed an effective method to estimate the modulation amplitude using the width of the noise spectrum caused by Rayleigh scattering, eliminating the need for an optical spectrum analyzer or modifications to existing equipment. However, the Rayleigh noise spectrum often displays a three-layered structure, complicating the identification of the appropriate spectral components for estimating the modulation amplitude. In this work, we investigate the origins of this three-layered Rayleigh noise spectrum and identify the directivity of an optical circulator as the source of the third noise component. As replacing the circulator with alternative optical components is not easy, it remains an essential part of the system. Our analysis shows that the third noise component exhibits significantly small variation in spectral width with changes in modulation frequency compared to the first and second components. This characteristic allows for the effective separation and identification of the third noise component, thereby enhancing the accuracy and convenience of modulation amplitude estimation in BOCDR.

Oxide fiber-reinforced oxide matrix composites (Ox/Ox-CMCs) were fabricated by vacuum-assisted impregnation and pressureless sintering using a high-yield alumina precursor. The Ox/Ox-CMCs were sintered at 1100 and 1200 °C for 2 h. SEM and X-ray CT revealed that in both cases the matrix formed successfully within and between the woven fabrics. Vickers hardness of the sintered matrix was independent of the location within each composite. In a three-point bending test, a bending fracture at the tensile side occurred prior to shear fracture, suggesting that the matrix achieved good adhesion between the woven fabrics. The Ox/Ox-CMC sintered at 1100 °C showed higher tensile strength than that sintered at 1200 °C. This strength difference was attributed to their microstructures; the specimen sintered at 1100 °C showed crack deflection at the fiber/matrix interface, while that sintered at 1200 °C had a strongly adherent interface. Both composites showed notch-insensitive behavior in double-edge notch tensile tests.