Mechanism
Synbiotics combine probiotic strains (selected SCFA producers) with prebiotic fibers (inulin, FOS, or resistant starch) to restore the depleted commensal ecology characteristic of PDAC. The prebiotic substrate selectively feeds reintroduced beneficial taxa, enabling competitive exclusion of pathobionts.
Rationale
PDAC is associated with a severely disrupted gut microbiome — depletion of butyrate-producing Faecalibacterium and Roseburia, with enrichment of pro-inflammatory and potentially oncogenic taxa. This intervention applies two-sided ecological engineering (Primitive 5): suppress pathobionts by restoring the missing beneficial functions rather than targeting pathogens directly.
Evidence Status
- Preclinical: Animal models show synbiotic supplementation improves anti-tumor immune responses and reduces tumor burden.
- Observational: PDAC patients consistently show SCFA-producer depletion correlating with worse outcomes.
- Clinical: No completed RCTs specific to PDAC synbiotic intervention.
Open Questions
- Optimal strain-prebiotic combinations for PDAC-specific dysbiosis patterns.
- Whether synbiotics improve chemotherapy response or reduce treatment toxicity.
- Timing of intervention relative to surgical resection.