Fig. 2: Drug treatment of Com20 facilitates the growth of S. Tm through alterations in community biomass, composition and function.

a,b, S. Tm growth as measured by luminescence (a) and the OD₅₇₈ of drug-treated Com20 (b) in the challenge assay separated by colonization groups. Values were normalized to the value of untreated Com20. Each point represents the mean across three biological replicates. Red lines represent the mean ± 1 s.e.m. c, Biplot and principal coordinate analysis of drug-treated Com20 based on Bray–Curtis distances. Each point represents a drug-treated community coloured by colonization group (untreated controls are shown in grey). The direction of the arrows indicates the correlation of the abundance of a species with each principal coordinate (PCo1 and PCo2), and their length reflects the strength of the association. d, Growth of S. Tm in 19-member communities that lack one member of the Com20 community compared with its growth in the full Com20 community. S. perfringens is highlighted in bold (Extended Data Fig. 6f–h). Red lines represent the mean ± 1 s.e.m. across three biological replicates. P values are from two-sided t-tests (only values ≤0.05 are shown). e, Distribution of mean S. Tm gene expression levels in co-culture with Com20 or in monoculture in three biological replicates per treatment. TPM, transcripts per million. Black vertical lines indicate quartiles. f, Principal component analysis (PC1 and PC2) of S. Tm gene expression based on the 500 genes with the highest variance across treatments. g, Distribution of mean gene expression levels of each Com20 member across treatments in three biological replicates. Black vertical lines indicate quartiles.

Source data