Fig. 8: P. russellii produces IPA and improves HMGCS2-mediated LGR5+ ISC proliferation.
a–d Violin plots overlaid with boxplots depict metagenomic abundances of P. russellii in patients with IBD and healthy controls across four independent cohorts. The width of each violin represents the kernel density estimation of the data distribution. Boxes represent the interquartile range between the first and third quartiles and the median (internal line). Whiskers denote the lowest and highest values within 1.5 times the range of the first and third quartiles, respectively; dots represent outlier samples beyond the whiskers. Individual points represent single samples. e Two-sided Spearman’s rank correlation and two-sided linear regression analysis between IPA and P. russellii in CD cohort (n = 32). f IPA production by P. russellii vs C. sporogenes in Trp-supplemented media (n = 3). g Lgr5 expression in crypts isolated from Hmgcs2fl/fl and Hmgcs2ΔIEC mice colonized with 109 CFU P. russellii post-DSS (n = 6). h, i Fecal/serum IPA in GF mice colonized with FMT or P. russellii (n = 4). j–q GF-DSS model colonized with FMT/P. russellii (n = 6): D3 ketogenesis/ISC markers (j–l); D7 phenotypes (m–o); qRT-PCR of Il1b, Il6, Tnfa in colon and OCLN, ZO-1, Muc2 in cIECs (p, q). r Mechanistic schema of P. russellii-IPA-HMGCS2 axis. Data represent mean ± SD (≥2 experiments). Two-sided Wilcoxon rank-sum tests (a–d) with BH adjusted P values, and two-sided t-tests (f–q) were used to assess statistical significance. Source data are provided as a Source data file.
