Fig. 18
Predicted effects of probiotic supplementation on epithelial cells, immune cell densities and cytokine concentrations with age. The predicted volume fraction of (a) healthy and (b) damaged epithelial cells, densities of (c) macrophages, (d) regulatory cells, (e) T-cells and (f) plasma B-cells and concentrations of (g) anti- and (h) pro-inflammatory cytokines with age, from solving Eqs. (3)–(23) with baseline parameters given in Tables 1, 2 and 3 and age functions given in Figs. 2, 3, 4 and 5. Solid lines represent baseline values of vitamin D intake \(D^{0}=4.8\) and \(D^{1}=0.5\) nmol/L day−1 and dashed lines \(D^{0}=3.2\) and \(D^{1}=0.35\) nmol/L day−1. A constant daily intervention of probiotics \(\mathrm {5\times 10}^{9}\) CFU/day is administered from day 0 to day 200 to individuals aged 20 (blue), 40 (red), 60 (green) and 80 (orange) years.
