AbstractThis research aimed to examine the possible effectiveness of treatment with a freshly formulated new probiotic versus Phaleria macrocarpa leaves extract indicated by the histopathological changes occurred to the colon of the immunocompromised New Zealand White (NZW) rabbits. The study included 40 rabbits, divided into 4 groups. Three of the groups were fed with the immunosuppressive medication (azathioprine, 500 mg/kg/day) to be immunocompromised, Group B was treated with P. macrocarpa extract, Group Ctreated with our developed probiotic, and the group D left untreated as a positive control, Group A regarded as control negative. The duration of immunocompromising drug induction was set as 14 days; and the period of treatment was set for another 14 days. Distinctly, the treated rabbits were showing improvements of healing processes compared to non-treated, where the signs of lack of normal mucous folds, different degrees of mucosal edema and congestion, submucosal hemorrhage, accumulati.....