Selective nourishing of gut microbiota with amino acids: A novel prebiotic approach?

Abstract

Prebiotics are dietary substrates which promote host health when utilized by desirable intestinal bacteria. The most commonly used prebiotics are non-digestible oligosaccharides but the prebiotic properties of other types of nutrients such as polyphenols are emerging. Here, we review recent evidence showing that amino acids (AA) could function as a novel class of prebiotics based on: (i) the modulation of gut microbiota composition, (ii) the use by selective intestinal bacteria and the transformation into bioactive metabolites and (iii) the positive impact on host health. The capacity of intestinal bacteria to metabolize individual AA is species or strain specific and this property is an opportunity to favor the growth of beneficial bacteria while constraining the development of pathogens. In addition, the chemical diversity of AA leads to the production of multiple bacterial metabolites with broad biological activities that could mediate their prebiotic properties. In this context, we introduce the concept of “Aminobiotics,” which refers to the functional role of some AA as prebiotics. We also present studies that revealed synergistic effects of the co-administration of AA with probiotic bacteria, indicating that AA can be used to design novel symbiotics. Finally, we discuss the difficulty to bring free AA to the distal gut microbiota and we propose potential solutions such as the use of delivery systems including encapsulation to bypass absorption in the small intestine. Future studies will need to further identify individual AA, dose and mode of administration to optimize prebiotic effects for the benefit of human and animal health.

Dietary supplementation of ark clams protects gut health and modifies gut microbiota in d‐galactose‐induced aging rats

“…For example, taurine, the most abundant amino acid in SS and TG ark clams, has been shown to alter the gut microbiota, affect the restoration of intestinal homeostasis, and increase the production of SCFAs 65 . Other amino acids and minerals, including arginine, glutamine, leucine, proline, threonine, tryptophan, calcium, magnesium, and iron, were also reported to modulate the gut microbiota composition both in vitro and in vivo 66‐68 . The precise mechanisms responsible for the modulating effects of these amino acids and minerals on gut microbiota are currently unclear and warrant further in‐depth exploration in future studies.…”

“…65 Other amino acids and minerals, including arginine, glutamine, leucine, proline, threonine, tryptophan, calcium, magnesium, and iron, were also reported to modulate the gut microbiota composition both in vitro and in vivo. [66][67][68] The precise mechanisms responsible for the modulating effects of these amino acids and minerals on gut microbiota are currently unclear and warrant further in-depth exploration in future studies.…”

Overall biomass yield on multiple nutrient sources

“…Nutrient utilization e ciency is important in other contexts, including evolution, microbiome-host interactions and synthetic biology. For example, different nutrient combinations have been shown to impact the gut microbiome [44,45], sometimes unintuitively where supplementation of another nutrient such as an amino acid reduces the overall biomass gain of gut bacteria [46]. Our observation showing the effects of amino acid supplementation on the overall biomass yield and speci cally the reduced biomass gain due to supplementation of methionine could help elucidate the phenomenon.…”

Role of Inflammatory Mechanisms in Major Depressive Disorder: From Etiology to Potential Pharmacological Targets

“…Notably, SCFAs can enter the bloodstream, cross the BBB, and reach the brain, where they can exerce anti-inflammatory and pro-neurogenic effects, modulate neurotransmitter systems including the glutamatergic, GABAergic, serotonergic, dopaminergic, adrenergic, and noradrenergic systems, and maintain BBB integrity [ 195 , 196 , 197 , 198 ]. Gut microbiota is also capable of producing various neurotransmitters (GABA, serotonin, dopamine, and norepinephrine) and polyamines, which can then act both in the periphery and within the CNS [ 199 , 200 ].…”