Conventional Rationale
Broad-spectrum antibiotics are sometimes prescribed to reduce bacterial load and manage infection-driven inflammation in Crohn's disease flares.
Why It's Counterproductive
The Crohn's signature shows that the primary problem is loss of beneficial commensals (F. prausnitzii, Roseburia, Lachnospiraceae), not overgrowth of pathogens per se. Broad-spectrum antibiotics obliterate these remaining SCFA producers, worsening the dysbiosis that drives the disease.
Critical evidence: the microbiome is required for heavy metal detoxification. Antibiotic-treated mice and germ-free mice accumulate significantly MORE arsenic in organs and show higher mortality from arsenic exposure coryell 2018 gut microbiome arsenic toxicity protection. Faecalibacterium specifically was identified as a key protective taxon for arsenic metabolism. Destroying it with antibiotics removes this protection.
Alternative Approach
- ecoli nissle 1917 — competitive exclusion of AIEC without collateral damage to commensals
- Targeted bacteriophage therapy — selectively targets pathobionts while sparing commensals
- Distal-fermenting prebiotics (gum arabic, PHGG, psyllium) to restore depleted SCFA producers
- Tributyrin supplementation to directly replace missing butyrate while ecology is repaired
Knowledge Primitive
Primitive 5: Two-Sided Ecological Engineering — You must suppress pathogens AND restore missing beneficial functions. Broad-spectrum antibiotics only do the first (poorly) while actively destroying the second.