Fig. 2: Comparative efficacy of in vitro and in vivo induction strategies for enhancing bile acid-metabolizing capacity.

a In vitro induction workflow. B. animalis subsp. lactis H22B656 was serially passaged ten times in MRS-cys medium supplemented with 0.3% (w/v) conjugated bile acids. After the tenth passage, 60 single colonies were randomly isolated and assayed for BSH-specific activity. b Fold-change distribution of BSH specific activity for the n = 60 biologically independent in vitro induced clones relative to the parental strain. The green dashed line at 1.0 indicates baseline activity; gray points represent clones with unchanged or reduced activity. Data for each isolate are presented as a box plot with overlaid individual data points. Box plot elements represent the median (centre line), the 25th and 75th percentiles (bounds of the box), and the minimum to maximum range. For each isolate, the box plot represents n = 3 biologically independent samples. c In vivo induction workflow. GF C57BL/6J mice (n = 4) were mono-colonized by oral gavage with H22B656 (1 × 10⁹ CFU/day for three days) and then maintained on stepwise high-fat, high-cholesterol diets (30%, 45%, and 60% fat + 0.2% cholesterol) over seven weeks. Fecal samples were collected at weeks 1, 3, 5, and 7; at each time point, 60 colonies were randomly isolated and assayed for BSH specific activity. d Fold-change distribution of BSH specific activity for the 60 in vivo induced isolates. Data for each isolate are presented as a box plot with overlaid individual data points. Box plot elements are defined as in (b). For each isolate, the box plot is derived from n = 3 biologically independent bacterial cultures. Panels (a) and (c) were created with BioRender (Zhang, J. (2026) https://BioRender.com/3qyx3m3). Source data are provided as a Source Data file.