(A) Brain regions dissected for RNA sequencing. Black lines indicate the
performed incisions. (B) Venn diagram reporting overlap in differentially
expressed genes in the gut and brain across all contrasts of gut microbiota
colonization treatments (CL, CL_13, and CL_Bifi) versus
microbiota-depleted (MD) controls (for the brain, the reported number of DEGs
includes both whole-brain and brain-region-specific comparisons, see Supplementary Table 6 and
Methods). (C) Venn diagram reporting
overlap in brain-region-specific contrasts of all gut microbiota colonization
treatments (CL, CL_13, and CL_Bifi) versus microbiota- depleted
(MD) controls. The brain icons were created with BioRender.com. Semantic
similarity scatterplots summarize the list of enriched (D) Biological process
and (E) Molecular function GO terms of all the 91 DEGs identified in the brain.
The scatterplots show GO terms as circles arranged such that those that are most
similar in two-dimensional semantic space are placed nearest to each other.
Circle color represents –log10 of enrichment P value, as
calculated by hypergeometric tests for over-representation: (D) cellular
metabolic compound salvage (GO:0043094), P=0.003, DNA
conformation change (GO:0071103), P=0.007, DNA packaging
(GO:0006323), P=0.008, cellular amino acid biosynthetic process
(GO:0008652), P=0.015, small molecule metabolic process
(GO:0044281), P=0.024, carbohydrate metabolic process
(GO:0005975), P=0.029, homeostatic process (GO:0042592),
P=0.046; (E) transaminase activity (GO:0008483),
P=0.006, chitin binding (GO:0008061),
P=0.007, NAD binding (GO:0051287), P=0.019,
oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as
acceptor (GO:0016616), P=0.044.