Microbial Metabolites and Gut Immunology

TL;DR: The gut microbiota plays a crucial role in immune system regulation, influencing host metabolism and immunity through complex interactions with the mucosal immune system, and dysbiosis is linked to various autoimmune diseases and disorders.

TL;DR: Sustained butyrate delivery via polymeric micelles in the lower gut prolongs survival of distal skin allografts in mice by modulating the myeloid cell compartment, without affecting Tregs or adaptive alloimmune responses.

Abstract: Objectives To test whether habitual pre-operative dietary fibre predicts 12-week immune–inflammatory recovery after oesophagectomy. Methods We conducted a multicentre prospective cohort across three tertiary hospitals. Adults with resectable oesophageal cancer completed a validated FFQ; total fibre (energy-adjusted) was grouped into sex-specific quartiles. Prespecified week-12 endpoints were: (i) a favourable inflammatory profile (CRP within reference or ≥50% fall plus NLR ≤ 3.0) and (ii) lymphocyte recovery (≥30% rise or ≥1.5 × 10^9·L −1 ). Robust Poisson models (clustered by site) estimated adjusted relative risks; dose–response was expressed per 10 g·day −1 . Longitudinal biomarker trajectories (baseline→post-operative day 7 → week 12) used mixed-effects models. Results Among 312 participants, event rates increased monotonically with higher fibre. Versus Q1, adjusted RRs for the favourable inflammatory profile were 2.36 (1.85–3.01) in Q3 and 2.62 (2.20–3.12) in Q4; for lymphocyte recovery, 1.63 (1.39–1.92) and 1.79 (1.65–1.95), respectively. Each +10 g·day −1 of fibre associated with RR 1.56 (1.34–1.82) for the favourable profile and 1.30 (1.17–1.45) for lymphocyte recovery. CRP and NLR declined more steeply and lymphocyte counts rose more in higher-fibre groups (time×quartile p = 1.68 × 10 −4 ; 1.21 × 10 −4 ; 2.26 × 10 −10 ). Early infections and 30-day mortality did not differ convincingly (per-10 g RR 0.84, p = 0.333; overall 1.0%). FFQ–record ICC for fibre was 0.87. Conclusion Higher habitual fibre before surgery was associated with materially better week-12 immune–inflammatory recovery after oesophagectomy, with consistent dose–response and longitudinal signals across centres. Routine pre-operative fibre appraisal offers a low-cost, clinic-ready stratifier for counselling and prehabilitation; interventional studies should test whether augmenting habitual fibre improves recovery trajectories.

TL;DR: Sodium acetate supplementation in rabbits enhances growth performance and intestinal health by activating the Wnt/β-catenin signaling pathway, improving feed efficiency, reducing diarrhoea, and increasing muscle fiber diameter and antioxidant capacity in the cecum.

TL;DR: This overview emphasizes the important role played by cross-feeding of intermediary metabolites (in particular lactate, succinate and 1,2-propanediol) between different gut bacteria.

TL;DR: A metabolic pathway whereby Trp metabolites from the microbiota balance mucosal reactivity in mice is described, whereby highly adaptive lactobacilli are expanded and produce an aryl hydrocarbon receptor (AhR) ligand-indole-3-aldehyde-that contributes to AhR-dependent Il22 transcription.

TL;DR: A mechanism by which Fn can drive CRC is unveiled and FadA is identified as a potential diagnostic and therapeutic target for CRC.

TL;DR: It is shown that senescence-associated secretory phenotype (SASP) has crucial roles in promoting obesity-associated hepatocellular carcinoma (HCC) development in mice, and a similar pathway may contribute to at least certain aspects of obesity- associated HCC development in humans as well.