Fig. 6
The oral administration of Bacteroides fragilis facilitates the intestinal epithelial barrier function and serum metabolomics analysis. a Activities of serum diamine oxidase (Ctrl control, BF Bacteroides fragilis, BO Bacteroides ovatus, AKK Akkermansia muciniphila; Mix, three-bacteria consortium [containing equal numbers of Bacteroides fragilis, Bacteroides ovatus, and Akkermansia muciniphila]). b Levels of serum endotoxin. c Levels of serum D-lactic acid. d Plasma FD4 levels. e Lactulose/mannitol ratio. f Representative western blotting of ZO-1, E-cadherin, Connexin 43, and β-tubulin in jejunal epithelium of mice. g–i Quantitation of the ZO-1 (g), E-cadherin (h), Connexin 43 (i) levels normalized to β-tubulin levels. j OPLS-DA of serum metabolites. k Principal component analysis of serum metabolites. l Volcano plot analysis of serum metabolites. m The enrichment analysis of KEGG pathways by differential serum metabolites. The data are presented as the mean ± SEM and evaluated by one-way ANOVA with adjustment for multiple comparisons in a–c (n = 10). The data are presented as the mean ± SEM and evaluated using Student’s t-test in d (n = 8), e (n = 8), and g–i (n = 3). In addition, the data were assessed by the VIP ≥ 1 from OPLS-DA, absolute Log2 (fold change) ≥ 1, and p-value < 0.05 in l (n = 6). **p < 0.01, *p < 0.05