Digestive System

Navigational overlay for the gastrointestinal tract — from the oral cavity (its first segment) through liver, pancreas, and the gut microbiome. The best-developed aging biology in this system is currently the gut microbiome — its compositional drift, barrier failure (“leaky gut”), and contribution to inflammaging are an active research front and a dedicated hallmark (dysbiosis). The oral/periodontal cluster is the second well-developed area (see below). Solid-organ pages (liver, intestine, pancreas) are largely planned.

Processes & barrier biology

• gut-barrier — intestinal barrier integrity; “leaky gut” and systemic inflammaging
• gut-microbiome-aging-shifts — age-related compositional change
• oral-microbiome-aging-shifts — age-related compositional change in the oral/subgingival niche

Oral cavity & periodontium

The mouth is the entry segment of the digestive tract and the second-best-developed aging cluster in this system. The supporting apparatus of the tooth (the periodontium) is built from three atomic tissues, and its age-associated breakdown produces a graded sequence of phenotypes.

• Tissues: gingiva (gums) · periodontal-ligament (PDL; tooth-suspending fibers + PDL stem cells) · alveolar-bone (tooth-bearing bone; also skeletal — cross-linked to bone)
• Microbiology: oral-microbiome-aging-shifts · porphyromonas-gingivalis (keystone pathogen)
• Phenotypes (graded sequence): gingival-recession (receding gums) → periodontitis → tooth-loss/edentulism → masticatory dysfunction feeding frailty and sarcopenia

Microbiome (atomic taxa)

• firmicutes-bacteroidetes-ratio — the most-cited aging microbiome metric
• akkermansia-muciniphila · bifidobacterium · lactobacillus — taxa with aging-relevant shifts
• porphyromonas-gingivalis — keystone oral pathogen (periodontitis; oral→systemic axis)
• ewingella-americana — lower-vertebrate-derived therapeutic candidate

Aging phenotypes

• type-2-diabetes — metabolic disease with strong gut-microbiome and pancreatic-islet components (shared with endocrine-system)
• periodontitis · gingival-recession · tooth-loss — oral/periodontal aging phenotypes (see Oral cavity cluster above)

Related interventions

• Dietary: caloric-restriction, ketogenic-diet, phosphate-additive-reduction; prebiotics/postbiotics/FMT

Auto-aggregated tissue members

LIST FROM "tissues"
WHERE parent-system = "digestive-system"
SORT file.name

Missing / planned pages

• liver and pancreas — now seeded as stubs (need full content); liver has an ingested primate snRNA aging study (yang-2023-primate-liver-aging-snrna-srebp2)
• [[intestine]], [[stomach]], [[colon]], [[esophagus]], [[gallbladder]] — solid-organ/segment pages not yet seeded stub
• [[enterocytes]], [[intestinal-stem-cells]], [[hepatocytes]] — cell types not yet seeded stub

See also

• by-organ-system — index of all body-system MOCs
• dysbiosis — the gut-microbiome hallmark
• endocrine-system — pancreatic islets / glucose homeostasis overlap