Mostly Microbes and Infection - by David Ojcius

A study maps age‑related gut microbiome shifts and introduces MicroAge, a microbiome‑based aging clock. It identifies  Bifidobacterium   pseudocatenulatum as a geroprotective species depleted with age. In mice, supplementation restored intestinal balance, reduced systemic inflammaging, improved cognition and motor function, and extended healthspan. Its metabolite  5-aminovaleric acid betaine (5-AVAB)  reproduced many benefits.

Defined human Clostridia consortia 17‑mix and 11‑mix reverse established colitis in multiple murine IBD models. Beyond SCFA and IL‑10 pathways, these live biotherapeutic products suppress resident pathobionts and activate anti‑inflammatory AhR signaling via bacterial tryptophan metabolites, revealing IL‑10‑independent mechanisms of microbiome‑based therapy.

Gut microbiome diversity and composition differed across predefined age groups in a Taiwanese cohort. Several age‑associated genera showed partial agreement across complementary analytic methods. Adult gut microbiome profiles could predict chronological age, though only with modest accuracy, underscoring both biological signal and methodological limits.

Bacterial endosymbionts in Fusarium oxysporum enhance fungal virulence by reshaping the rhizosphere microbiome. Achromobacter spp. endosymbionts reduce disease‑suppressive bacteria, including Streptomyces, through beauvericin production. This tripartite interaction weakens microbiome‑based plant defense and intensifies pathogen impact.

Paired oral–fecal microbiomes from 507 individuals revealed elevated mouth‑to‑gut bacterial transmission in gastrointestinal cancers. A mouth‑to‑feces index captured disease‑specific signatures and powered a classifier that outperformed fecal occult blood testing, enabling sensitive, non‑invasive detection across multiple cohorts.

Gut microbes convert dietary nitrate and non‑heme iron into dinitrosyl iron complexes (DNICs) that circulate systemically and improve host metabolism. DNICs were detected in conventional but not germ‑free mice, and supplementation or synthetic DNICs boosted tissue levels and reduced cardiometabolic dysfunction. DNICs also lowered steatosis and normalized sGC‑mTORC1 signaling.