  We analyze the data from two recent experiments designed to search for solar
axions within the context of multidimensional theories of the Kaluza-Klein
type. In these experiments, axions were supposed to be emitted from the solar
core, in M1 transitions between the first excited state and the ground state of
57Fe and 7Li. Because of the high multiplicity of axionic Kaluza-Klein states
which couple with the strength of ordinary QCD axions, we obtain much more
stringent experimental limits on the four-dimensional Peccei-Quinn breaking
scale f_{PQ}, compared with the solar QCD axion limit. Specifically, for the
57Fe experiment, f_{PQ}>1x10^6 GeV in theories with two extra dimensions and a
higher-dimensional gravitational scale M_H of order 100 TeV, and f_{PQ}>1x10^6
GeV in theories with three extra dimensions and M_H of order 1 TeV (to be
compared with the QCD axion limit, f_{PQ}>8x10^3 GeV). For the 7Li experiment,
f_{PQ}>1.4x10^5 GeV and 3.4x10^5 GeV, respectively (to be compared with the QCD
axion limit, f_{PQ}>1.9x10^2 GeV). It is an interesting feature of our results
that, in most cases, the obtained limit on f_{PQ} cannot be coupled with the
mass of the axion, which is essentially set by the (common) radius of the extra
dimensions.
