Fig. 6. Fiber-rich or starch-rich diet exhibits distinct microbiome carbohydrate and hydrogen metabolic pathways in bovine rumen.

A consolidating analysis on enzymes, microorganisms of Hungate1000 collection, metabolites and pathways recruitment. “+ H₂”, H₂ produced; “- H₂”, H₂ consumed. The fold changes (left: fiber-rich/starch-rich; right: starch-rich/fiber-rich) of enzymes or microorganisms in each group are labeled besides, and presented in additional file S8 in details; B proposed rumen H₂ metabolism models. Representative species or genus and corresponding hydrogenases are shown next to the arrow, and extracted from Figs. 1B, C, 4A, 5, and additional file S8. The solid and dotted line (square) indicated trends of enhanced and reduced pathways, respectively. H₂ hydrogen. The upward arrows, increased metabolites; the downward arrows, decreased metabolites.