加载中…
Place · Level 3
从口到肛门 · 9 米的化学工厂 · 70% 免疫驻地 · 与微生物共生 · 第二大脑就在这里
synergy · 1
~70% of immune cells reside in the gut (Peyer's patches/GALT); barrier leakiness → bacterial translocation → systemic inflammation. 'Gut as immune training ground' is literal.
cofactor · 1
H. pylori does not survive in stomach acid; it burrows under the mucus layer and sits on the epithelial surface, where the pH is near neutral — the one mild spot in the stomach. Understanding that move requires knowing how the acid is made and how the mucus barrier works.
regulates · 6
The liver produces ~600 mL bile daily; gut FXR receptors feed bile-acid reabsorption signals back. In NASH, disrupted enterohepatic signaling is the key second hit.
Gut produces ~90% of body 5-HT; SCFA activates GPR41/43 → vagus → brain. The brain controls motility via ENS 500M neurons. The 'second brain' is literal.
The gut is the body's largest endocrine organ: GLP-1 stimulates insulin + appetite suppression; GIP modulates lipids; ghrelin triggers hunger. The postprandial incretin effect underpins GLP-1 receptor agonist therapy.
↔GERD
GERD = LES barrier failure + delayed gastric emptying + reduced esophageal clearance + impaired mucosal defence. ACG 2022 ladder: lifestyle (weight loss / head-of-bed 15 cm / food diary) → H2RA / PPI 8 wk → refractory → vonoprazan / anti-reflux surgery. Barrett surveillance per ACG 2022.
Portal blood feeds liver directly → gut-microbial products (LPS, SCFA, secondary bile acids) are major hepatic metabolic + inflammatory signals. NAFLD two-hit model: hepatic fat + gut-derived LPS → NASH progression.
↔IBS
IBS is not only a bowel problem — it sits on the gut-brain axis, where the vagus runs both ways and about 80% of its fibres are afferent (gut to brain). That is a fibre count, not a measure of signal traffic — the two are routinely conflated. Looking for a lesion in the bowel alone usually finds nothing and moves nothing.