Fig. 16
Predicted effects of probiotic supplementation on nutrients and bacteria with age. The predicted concentrations of (a) macronutrients, (b) micronutrients, (c) metabolites, (d) alternate nutrients and populations of (e) commensals and (f) pathogens 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.
