You Talking to Me? Says the Enteric Nervous System (ENS) to the Microbe. How Intestinal Microbes Interact with the ENS

Abstract

Mammalian organisms form intimate interfaces with commensal and pathogenic gut microorganisms. Increasing evidence suggests a close interaction between gut microorganisms and the enteric nervous system (ENS), as the first interface to the central nervous system. Each microorganism can exert a different effect on the ENS, including phenotypical neuronal changes or the induction of chemical transmitters that interact with ENS neurons. Some pathogenic bacteria take advantage of the ENS to create a more suitable environment for their growth or to promote the effects of their toxins. In addition, some commensal bacteria can affect the central nervous system (CNS) by locally interacting with the ENS. From the current knowledge emerges an interesting field that may shape future concepts on the pathogen–host synergic interaction. The aim of this narrative review is to report the current findings regarding the inter-relationships between bacteria, viruses, and parasites and the ENS.

Interconnections between the Oral and Gut Microbiomes: Reversal of Microbial Dysbiosis and the Balance between Systemic Health and Disease

“…In eubiosis, these microbial communities perform necessary functions such as nutrient conversion, vitamin formation, and immune tolerance [19]. In addition, a eubiotic gut microbiota aids in the maintenance of hepatic health [20] and can ward off neurological diseases that stem from communication between the enteric and central nervous systems [21], highlighting the importance of GI eubiosis to overall health.…”

Entamoeba histolytica—Gut Microbiota Interaction: More Than Meets the Eye

“…Gut microbial dysbiosis causes changes in SCFAs production leading, for example, to liver diseases [ 49 ] and neurodegenerative disorders [ 50 ]. The effect of chemical molecules originating from bacteria on the physiology of Entamoeba parasites has been pioneered by a study on SCFAs and their role in inhibiting encystation [ 51 ].…”

The Contribution of Gut Microbiota–Brain Axis in the Development of Brain Disorders

“…Functional aspects of the gastrointestinal tract such as peristaltic movements, the transport of substances, and the local flow of blood are all regulated by a network of neuronal ganglia known as the enteric nervous system (ENS) ( Furness, 2000 ; Furness et al, 2004 ). It is known that the neurons of the ENS communicate with each other using the same “language” as in the CNS ( Giuffrè et al, 2020 ). The ENS consists of two ganglion plexuses composed of neurons and glia that regulate a variety of gastrointestinal functions and are essential for life ( Furness, 2006 ).…”

“…It is interesting to note that with the administration of the conventional microbiota, the recovery of GF mice saw the density and physiology of the ENS in the intestine normalized ( Kashyap et al, 2013 ). Every microorganism can have a different effect on the ENS: some commensal bacteria may have a local effect interacting with the ENS, while pathogenic bacteria benefit from the ENS by creating an environment more suited to their growth and advantageous for their effects ( Giuffrè et al, 2020 ). The control exercised by the gut microbiota takes place through the vagus nerve and the ENS ( Borre et al, 2014 ; Kaelberer et al, 2018 ): classic examples are provided by the bacteria Lactobacillus rhamnosus , which can modulate anxious behavior, and Bifidobacterium longum NCC3001, which exerts anxiolytic effects.…”