We investigated the molecular simulations based on the Gibbs ensemble Monte Carlo method, which was previously applied to the colloidal suspensions confined with a narrow pore. The long-range electrostatic interactions between the particle and the adjacent fiber and between pairs of particles are evaluated by adopting the earlier methods. For uncharged cases, the partition coefficient with non-dilute particle concentration decreases with increases in the ratio of particle radius to fiber radius. For charged systems with constant surface charges of both the particle and the fiber, the electrostatic interactions result in a different behavior according to the variations of particle concentration. Note that the particle concentration is associated with the effects of steric exclusion as well as particle-particle interaction. By developing an effective adjusting trial, the particle concentration in the bulk region has been kept as a constant during the simulation. The predicted density profiles of colloids around a fiber indicate that, whether the particles are uncharged or charged, the particle-particle interaction plays a significant role.