Bi-directional elucidation of Lactiplantibacillus plantarum (RTA 8) intervention on the pathophysiology of gut-brain axis during Salmonella brain infection

BACKGROUND: There have been reports of patients suffering from typhoid fever, particularly those involving infants and immunocompromised patients, which at times present with Salmonella induced brain infection. Although rare, it has frequently been associated with adverse neurological complications and increased mortality. In this context, the gut-brain axis, involving two-way communication between the gut and the brain, holds immense significance as various gut ailments have been associated with psychiatric complications. In turn, several neurodegenerative diseases have been associated with an altered gut microbiota profile. Given the paucity of effective antimicrobials and increasing incidence of multi-drug resistance in pathogens, alternate treatment therapies such as probiotics have gained significant attention in the recent past. RESULTS: In the current study, prophylactic effect of Lactiplantibacillus plantarum (RTA 8) in preventing neurological complications occurring due to Salmonella brain infection was evaluated in a murine model. Along with a significant reduction in bacterial burden and improved histoarchitecture, L. plantarum (RTA 8) administration resulted in amelioration in the level of neurotransmitters such as serotonin, norepinephrine and dopamine in the gut as well as in the brain tissue. Simultaneously, increased gene expression of physiologically essential molecules such as mucin (MUC1 and MUC3) and brain-derived neurotrophic factor (BDNF) was also observed in this group. CONCLUSION: Present study highlights the potential benefits of a probiotic supplemented diet in improving various aspects of host health due to their multi-targeted approach, thereby resulting in multi-faceted gains.