Fig. 1

FMT treatment does not significantly increase HGT events in the recipient’s gut microbiome. HGT events were normalised by the number of microbial species present in each recipient sample (n = 323). Each point represents a participant’s sample. Boxes represent the interquartile range (IQR) split by the median, with whiskers expanding up to 1.5 × the IQR. Differences between groups over time were assessed using linear mixed models (group, sex, and timepoint fixed effects and recipient random effect). There were no significant differences between treatment groups, but a significant difference between baseline and week 26 was observed for both groups, ***p < 0.001. HGT, horizontal gene transfer; FMT, faecal microbiota transplantation