Fig. 7

Spearman’s rank correlation of the significantly changed faecal bacterial abundances with faecal (F) and urinary (U) metabolites in RYGB patients from cohort 1 (A). The colour bar indicates the correlation coefficient r values and the p values post Benjamini-Hochberg multiple test correction are indicated as ***p < 0.001, **p < 0.01, *p < 0.05. Summary of metabolic pathways of tyrosine, phenylalanine, tryptophan and choline and associated gut bacteria (B). Bacteria and metabolite names depicted red indicate increased abundance or concentrations post-RYGB compared to pre-op. Bold solid red lines indicate metabolite production by the gut bacteria observed in the culture experiments. Red arrows between molecules indicate enhanced metabolic pathways following the RYGB surgery. The dashed line between the metabolites and gut bacteria indicates significantly positive (red) and negative (blue) correlation. The uneven dashed line indicates multiple reaction steps. The red ovals (RYGB microbiota) indicate metabolic transformation steps in the batch culture of faecal samples from RYGB donors