Extended Data Fig. 5. Fecal gbuA trends downward after transition from a red meat to non-meat or white meat diet.

Using samples from the APPROACH study we assessed if gbuA abundance is regulated by diet. Participants were randomly assigned to consume red meat (highest L-carnitine containing diet), white meat, and non-meat (lowest L-carnitine containing diet) diets in one of six orders, with a washout period of at least two weeks between each diet intervention, as described under Methods. The two-week washout periods are expected to reduce the effect of white meat that occur between red meat and non-meat. To test the effect of this intermediate white meat diet on gbuA abundance, we separated those participants with and without an intermediate white meat diet. Using shotgun metagenomic sequencing gbuA abundance was calculated. Fecal gbuA decreased after transitioning from red meat to white meat, while no such change was detected after transition from white meat to non-meat.

(a) Fecal gbuA abundance (RPKM) in subjects while consuming a non-meat diet and after transition to a red meat diet without an intervening white meat diet.

(b) Fecal gbuA abundance (RPKM) in subjects while consuming a red-meat diet and after transition to a non-meat diet without an intervening white meat diet.

(c) Fecal gbuA abundance (RPKM) in subjects while consuming a non-meat diet and after transition to a red meat diet with an intervening white meat diet.

(d) Fecal gbuA abundance (RPKM) in subjects while consuming a red-meat diet and after transition to a non-meat diet with an intervening white meat diet.

(e) Fecal gbuA abundance (RPKM) in subjects consuming a white meat diet and after transition to a red meat diet regardless of intermediary diet consumption.

(f) Fecal gbuA abundance (RPKM) in subjects while consuming a red meat diet and after transition to a white meat diet regardless of intermediary diet consumption.

(g) Fecal gbuA abundance (RPKM) in subjects while consuming a non-meat diet and after transition to a white meat diet regardless of intermediary diet consumption.

(h) Fecal gbuA abundance (RPKM) in subjects while consuming a white meat diet and after transition to a non-meat diet regardless of intermediary diet consumption.

Median lines are shown and P values were determined by two-way Wilcox test.