Fig 1: UK4 increases Treg cells levels, while Fr1 decreases neutrophil levels. T regulatory cells (CD4+, CD25+, FoxP3+) were assessed in mesenteric lymph nodes (MLNs) (a) and were subsequently analysed for Helios expression (b), to investigate their origin as Helios+ cells exclusively originate in the thymus. Blood was also assessed for Treg cell levels (c), and plasma interleukin 10 (IL-10) levels (d). Similarly, neutrophil (CD11b+, LY6Cmid, SSChigh and CXCL1 levels were also investigated in peripheral blood (e, f). All data were normally distributed and analysed using a one-way ANOVA, followed by a Dunnett’s post hoc test. Significant differences are depicted as *p < 0.05, **p < 0.01; milk control compared to Kefir supplementation, $p < 0.05 and $$p < 0.01; undisturbed control compared to milk control. All data are expressed as mean ± SEM (n = 11–12). Dots on each graph represent individual animals