Fig. 3
Reg4 affects the composition and metabolites of the gut microbiota. a Flow cytometry of WGA+ and LPS+ bacteria in fresh feces of Reg4 KO (R4KO) and control WT (WT1) mice and in huREG4IECtg (HuR4) mice and their littermate controls (WT2). Iso, isotypic control. b The proportions of gut bacteria after the 16S rRNA sequencing of the gut microbiota in pooled ileal (SI) and colonic (Co) samples from WT and huREG4IECtg (HuR4) mice (three independent experiments, n = 5 mice, 7–8 weeks old, male). c LC-MS/MS analyses of peripheral blood of huREG4IECtg (NR1-NR5) mice and their control littermates (NW1-NW5) fed normal chow (n = 5). d Analyses of IAA in the fresh stools and peripheral blood of WT (WT1), Reg4 KO (R4KO), huREG4IECtg (HuR4) mice, and their control littermates (WT2) fed (HFD-WT, HFD-R4KO, or HFD-HuR4) or not fed (NCD-WT, NCD-R4KO, or NCD-HuR4) a HFD for 3 months. e QPCR of the iaaM and iaaH genes in the ileal (SI) and colonic (Co) samples from huREG4IECtg mice (HuR4) and their control littermates (WT2) (n = 6). Standard curves were prepared from serial dilutions of iaaM or iaaH, which were amplified in the guts of mice. f Proportion of different lactobacilli in the colons of WT (WT2) and huREG4IECtg mice (HuR4). g IAA levels in the supernatants of different Lactobacillus species. L. Joh, Lactobacillus johnsonii (BNCC, China); HuR4L.Joh-1, 2, 3, three different strains isolated from huREG4IECtg mice; HuR4L. Rut, an isolated strain of Lactobacillus reuteri from huREG4IECtg mice; L. Rut, Lactobacillus reuteri (BioGaaia, Sweden); L. Ani, Lactobacillus animalis (BNCC, China); L.Aci, Lactobacillus acidophilus (BNCC, China); Mut Lut, iaaM deleted Lactobacillus reuteri. The data are from three independent experiments. Student’s t test in all panels, mean ±SD. *p < 0.05, **p < 0.01, and ***p < 0.001