Injection of Lactobacillus casei strain Shirota affects autonomic nerve activities in a tissue‐specific manner, and regulates glucose and lipid metabolism in rats

Abstract

Aims/Introduction: Previously, it was observed that long-term ingestion of a probiotic strain Lactobacillus casei Shirota (LcS) ameliorates insulin resistance and glucose intolerance in rats fed a high-fat diet. In the present study, we examined its possible role in the autonomic nervous system during LcS-induced modulations in glucose and lipid metabolism or cardiovascular functions. Materials and Methods: The present study examined the effects of intragastric (IG) LcS injection on autonomic nerve tones in anesthetized rats by electrophysiological method. Results: We found that an IG injection of LcS suppressed neural activity of sympathetic nerves supplying the white adipose tissue of urethane-anesthetized rats in a dose-dependent manner, whereas sympathetic nerve outflow to brown adipose tissue was not affected by the IG LcS injection. Furthermore, the IG LcS injection reduced efferent sympathetic nerve outflow to the adrenal gland and liver, but did not alter gastric vagal nerve activity, renal sympathetic nerve activity, as well as mean arterial pressure. To test the involvement of afferent vagal nerves and the abdominal organs, we examined the adrenal sympathetic response to an LcS injection in rats with ablated afferent vagal nerves, and found that the adrenal sympathetic nerve response to LcS was inhibited in vagotomized rats. In addition, we found that oral ingestion of LcS attenuated the hyperglycemic response to glucose loading and blood glycerol levels in conscious rats. Conclusions: Our data suggest that LcS might affect tissue-specific autonomic nerves through the afferent vagal nerve pathway to modulate glucose and lipid metabolism.

Fermented Milk Containing Lactobacillus casei Strain Shirota Preserves the Diversity of the Gut Microbiota and Relieves Abdominal Dysfunction in Healthy Medical Students Exposed to Academic Stress

“…The pathway analysis of the 179 stress-responsive genes showed that the academic examination preferentially affected a group of genes related to lipid metabolism (e.g., ERCC2, FGF1, PPARGC1A, RARA, SREBF1). Interestingly, our previous study revealed that L. casei strain Shirota attenuated lipid metabolism via suppression of sympathetic nerve activity (41). The L. casei strain Shirota admin-istration prevented the additional changes in gene expression levels, including those of lipid metabolism-related genes (ERCC2, FGF1, PPARGC1A).…”

Diet-driven microbiota dysbiosis is associated with vagal remodeling and obesity

“…Earlier studies demonstrated that vagal pathways innervating the gastrointestinal tract, pancreas, and liver are involved in the control of assimilation, storage, mobilization, conversion, and oxidation of macronutrients [75, 76]. Lactobacillus has been hypothesized to modulate fat metabolism via a vagal-dependent pathway [77] and vagal ablation abolished -ornithine positive effects on lipid metabolism [78]. PPARγ signaling in NG has notably been hypothesized to regulate diet-driven thermogenesis [79].…”

l-Ornithine intake affects sympathetic nerve outflows and reduces body weight and food intake in rats

“…The afferent autonomic reflex in abdominal organs plays an important role in sensing various nutritional components that arrive in the gastrointestinal tract and for sending information to the central nervous system for regulating efferent autonomic nerves (Tanida et al, 2014;Tanida and Satomi, 2011). We previously found that IG injections of Lactobacillus (Tanida et al, 2014) or monosodium glutamate (Tanida and Satomi, 2011) affected efferent autonomic nerve discharges through the afferent vagal nerve in the digestive organs because efferent sympathetic responses to these agents were abolished in rats treated vagal nerve denervation (Tanida et al, 2014;Tanida and Satomi, 2011).…”

“…We previously found that IG injections of Lactobacillus (Tanida et al, 2014) or monosodium glutamate (Tanida and Satomi, 2011) affected efferent autonomic nerve discharges through the afferent vagal nerve in the digestive organs because efferent sympathetic responses to these agents were abolished in rats treated vagal nerve denervation (Tanida et al, 2014;Tanida and Satomi, 2011). In agreement with previous studies, we demonstrated that afferent vagal neurotransmission in the abdominal organs was implicated in the WAT response to l-ornithine, which was similar to the results in our previous reports (Tanida et al, 2014;Tanida and Satomi, 2011). This is a novel finding in that it indicates that l-ornithine ingestion might act on digestive organ sensors and cause a reflex response of the afferent vagal nerve, resulting in increased efferent sympathetic outflows to WAT and BAT through the central nervous system.…”