Fig 1: The gut microbiota is associated with Treg cell differentiation in Emu infection.a After depletion of the gut microbiota with antibiotic cocktail treatment (ABX), the proportion of colonic CD25+Foxp3+ Treg cells in the CD3+CD4+ cell population in Emu-infected (IN) mice was significantly decreased in comparison with that in the infected mice treated with Mock. Naive mice (N) with or without ABX treatment were included as controls. b Schematic showing the experimental design for fecal transplantation transfer (FMT). Recipient mice were pretreated with ABX cocktails for 2 weeks, followed by an FMT regime of 2 weeks from naive donors (ND) or helminth-infected donors (HID). c The proportion of colonic CD25+Foxp3+ Treg cells in the CD3+CD4+ cell population by flow cytometry analysis for the recipient mice. d The proportion of colonic Helios+ Treg cells in Foxp3+ Treg cells by flow cytometry analysis for the recipient mice. The flow cytometry analysis was performed at 4 weeks post-FMT engraftment. Experiments were repeated at least 2 times with similar results. The data shown are from a representative experiment (mean ± SD shown). ns, not significant; *P < 0.05, ***P < 0.001 using the two-sided Student t-test (n = 4–6 mice for panel a; n = 7 for panels (b–d)).