Role of Gut Microbiota in Neuroendocrine Regulation of Carbohydrate and Lipid Metabolism via the Microbiota-Gut-Brain-Liver Axis

Abstract

Gut microbiota play an important role in maintaining intestinal health and are involved in the metabolism of carbohydrates, lipids, and amino acids. Recent studies have shown that the central nervous system (CNS) and enteric nervous system (ENS) can interact with gut microbiota to regulate nutrient metabolism. The vagal nerve system communicates between the CNS and ENS to control gastrointestinal tract functions and feeding behavior. Vagal afferent neurons also express receptors for gut peptides that are secreted from enteroendocrine cells (EECs), such as cholecystokinin (CCK), ghrelin, leptin, peptide tyrosine tyrosine (PYY), glucagon-like peptide-1 (GLP-1), and 5-hydroxytryptamine (5-HT; serotonin). Gut microbiota can regulate levels of these gut peptides to influence the vagal afferent pathway and thus regulate intestinal metabolism via the microbiota-gut-brain axis. In addition, bile acids, short-chain fatty acids (SCFAs), trimethylamine-N-oxide (TMAO), and Immunoglobulin A (IgA) can also exert metabolic control through the microbiota-gut-liver axis. This review is mainly focused on the role of gut microbiota in neuroendocrine regulation of nutrient metabolism via the microbiota-gut-brain-liver axis.2 of 21 formate, acetate, propionate, and butyrate, which are related to maintaining intestinal epithelium and permeability [11]. Further, SCFAs regulate glucose and lipid metabolism as well as immune and inflammatory responses [12,13]. Hence, gut microbiota also plays an important role in immune systems, inflammation, and cancer prevention of the host [14,15]. The enteric nervous system (ENS) is reported to be involved in intestinal metabolic regulation, and enteric neurons and intestinal neurotransmitters play an important role in ENS regulation [16][17][18]. The gut contains full ENS reflex circuits, such as motor neurons, interneurons, and sensory neurons, and these neurons transfer information between the ENS and central nervous system (CNS). The vagal nerve pathway communicates between the CNS and ENS, which has remarkable impact on regulating gastrointestinal tract functions and feeding behavior [19,20]. Thus, the vagal nerve system is also involved in intestinal metabolic regulation through the gut-brain axis. Vagal afferent neurons express receptors for gut peptides, such as cholecystokinin (CCK), ghrelin, leptin, peptide tyrosine tyrosine (PYY), glucagon-like peptide-1 (GLP-1), 5-hydroxytryptamine (5-HT) and so on, which are secreted from enteroendocrine cells (EECs) [20][21][22]. When vagal afferent neurons sense these types of gut peptides, the corresponding gut information will transfer to the CNS and exert various reactions. At the same time, gut microbiota can regulate these gut peptides, such as CCK, ghrelin, leptin, PYY, GLP-1, 5-HT levels to influence vagal afferent pathway, and then regulated intestinal metabolic metabolism via the microbiota-gut-brain axis [23][24][25].The importance of the gut-brain axis in human health and disease has been known for a long period. However, it has only been re...

Sleep disorders related to nutrition and digestive diseases: a neglected clinical condition

“…(Fig. 1) [12][13][14][15]. However, little is known about the clinical impact of this emerging issue.…”

“…Sleep restriction has been associated with reduced concentrations of the satiety factor leptin, and increased concentrations of the hunger-promoting hormone ghrelin, altering their ability to signal the correct caloric requirement [48,49]. The dynamic interplay between the digestive system and sleep is an excellent example of the brain-body interaction ( Fig.1) [12][13][14][15]. The hypothalamus, particularly the lateral hypothalamic area, regulates the energy balance and coordinates peripheral cues of energy status, and weight-affecting behaviors.…”

“…An extensive bidirectional communication network between the GI tract and the central nervous system (CNS), referred to as the "gut-brain axis", has been widely investigated in the past decade ( Fig. 1) [12][13][14][15]. Recent studies linked psychiatric disorders, including depression, to changes in the microbiome [117,118].…”

Role of gut microbiota via the gut-liver-brain axis in digestive diseases

“…Changes in gut microbiota may stimulate liver fat deposition via the following mechanisms: Regulating intestinal permeability, increasing low-grade inflammation, regulating dietary choline metabolism, regulating bile acid metabolism, and producing endogenous ethanol[ 109 ]. And, gut microbiota has also been reported to play a role in the neuroendocrine regulation of lipid metabolism[ 110 ]. Furthermore, gut microbiota metabolites and ammonia may produce neurotoxic damage, which is related to the cognitive impairment of NASH[ 105 ], however, more research is necessary to fully understand the underlying mechanism of functional changes caused by cognitive impairment in NASH.…”

Features of Metabolic Coupling in the «superorganism» System (Host – Microbiota)

“…Третий путь метаболизма триптофана, который имеется как в энтероцитах, так и в других клетках человека, это путь продукции нейромедиатора -серотонина. Следует отметить, что образование более чем 90 % серотонина в организме человека происходит в кишечнике в энтерохромаффиных клетках [37]. Однако гематоэнцефалический барьер непроницаем для данного медиатора, и его основная функция локализована в желудочно-кишечном тракте.…”