This study aimed to investigate the effect of Lacticaseibacillus rhamnosus GG (LGG) fermented milk supplemented to different vegetable jams, on physiological and immunomodulatory activities in E. coli induced diarrhoeagenic mouse model. A 12.5% mortality with two days reduction in diarrhoeal duration was observed in LGG fermented milk supplemented tomato jam group as compared to 50% mortality in diarrhoeal control group. A reduction in daily feed intake and body weight was observed in the diarrhoeal control group. An increase in phagocytosis (35%) and reduction in splenocyte stimulation index was observed in the mice fed with LGG fermented milk supplemented tomato jam (p < 0.05). A significantly higher level of anti-inflammatory markers and immunoglobulins were observed in all the treatment groups in comparison to the diarrhoeal group. On the contrary, a higher level of proinflammatory markers, IL-6, IFN γ, CRP, TNF-α were observed in diarrhoeal conditions. A reduction in total E. coli counts in faeces without any translocation to other organs was observed in all the treatment groups. The molecular docking analysis revealed the role of phenolic acids towards higher levels of anti-inflammatory markers and carotenoids contributing towards reduced levels of proinflammatory markers. Furthermore, the Multidimensional Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) analysis ranked the tomato jam supplemented with LGG fermented milk may have potential in management of diarrhoeal conditions.