FOSB and alcohol drinking: Notably, the “alcoholism” pathway (mmu05034) was enriched in the B. wadsworthia-only group, which includes 24 genes linked to histone cluster 1 and the proto-oncogene AP-1 transcription factor subunit fosB, implicated in responses to addictive and compulsive behaviours54 (Supplementary Data 6, based on functional enrichment using WebGestalt).