Effects of Probiotic Strain of Lactobacillus Paracasei St11 (ncc2461) on Autonomic Nerve Activties, Blood Pressure and Appetite in Rats

In a recent study, we examined the glycemic and autonomic nervous responses to probiotic strain Lactobacillus johnsonii La1, and presented evidence that intraduodenal (ID) injection of this bacteria affected autonomic nerves and lowered blood pressure (BP) in anesthetized rats. In the study presented here, we examined the feeding, autonomic and cardiovascular effects of the lactobacillus strain Lactobacillus paracasei ST11 (NCC2461) in rats, and found that it suppressed food intake. Moreover, ID injection of NCC2461 suppressed gastric vagal nerve activity (GVNA) and accelerated renal sympathetic nerve activity (RSNA) and BP in a dose-dependent manner. Pretreatment with the histaminergic H1-receptor antagonist diphenhydramine eliminated the effects of NCC2461 on RSNA and BP. Furthermore, bilateral subdiaphragmatic vagotomy did not affect elevating effects of NCC2461, suggesting that vagal afferents are not involved in the pathway of NCC2461 effects. These evidences thus suggest that NCC2461 may exert its hypophagic and hypertensive actions through changes in autonomic neurotransmission via the central histaminergic nerves.