  To resolve the long-standing discrepancy between the precision measurement of
bottom quark forward-backward asymmetry at LEP/SLC and the Standard Model
prediction, we propose a novel method to probe the $Zb\bar{b}$ coupling by
measuring the single-spin asymmetry $A_e^b$ of the polarized lepton cross
section in neutral current DIS processes with a $b$-tagged jet at HERA and EIC.
Depending on the tagging efficiency of the final state $b$-jet, the measurement
of $A_e^b$ at HERA can already partially break the degeneracy found in the
anomalous $Zb\bar{b}$ coupling, as implied by the LEP and SLC precision
electroweak data. In the first year run of the EIC, the measurement of $A_e^b$
can already break the degeneracy, due to its much larger luminosity and higher
electron beam polarization. With enough integrated luminosity collected at the
EIC, it is possible to either verify or exclude the LEP data and resolve the
$A_{\rm FB}^b$ puzzle. We also discuss the complementary roles between the
proposed $A_e^b$ measurement at EIC and the measurement of $gg \to Zh$ cross
section at the HL-LHC in constraining the anomalous $Zb\bar{b}$ coupling.
