Emerging effects of tryptophan pathway metabolites and intestinal microbiota on metabolism and intestinal function

Hyland, Niall P.; Cavanaugh, Cassandre R.; Hornby, Pamela J.

doi:10.1007/s00726-022-03123-x

Cited by 52 publications

(55 citation statements)

References 118 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“… a Based on pathway descriptions provided by Hyland et al ( 90 ) and McReynolds et al ( 55 ) and KEGG database analysis ( 91 ). b Reciprocal BLASTp hits with indicated Caenorhabditis elegans protein based on genome sequence reported in Rougon-Cardoso et al ( 92 ).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Apex Predator Nematodes and Meso-Predator Bacteria Consume Their Basal Insect Prey through Discrete Stages of Chemical Transformations

et al. 2022

View full text Add to dashboard Cite

The processes by which organic life is consumed and reborn in a complex ecosystem were investigated through a multiomics approach applied to the tripartite Xenorhabdus bacterium- Steinernema nematode- Galleria insect symbiosis. Trophic analyses demonstrate the primary consumers of the insect are the bacteria, and the nematode in turn consumes the bacteria.

show abstract

Section: Resultsmentioning

confidence: 99%

“… a Based on pathway descriptions provided by Hyland et al ( 90 ) and McReynolds et al ( 55 ) and KEGG database analysis ( 91 ). …”

Section: Resultsmentioning

confidence: 99%

Apex Predator Nematodes and Meso-Predator Bacteria Consume Their Basal Insect Prey through Discrete Stages of Chemical Transformations

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The mean amount of tryptophan provided from all sources is 0.91 g/day, thus representing a usual consumption equal to 13.0 mg/kg body weight/day; thus, this value is well above the requirement [ 9 ]. In addition to being used by the different organs and tissues of the host body, a minor part of available tryptophan, approximately 5%, is metabolized by the gut microbes [ 5 ]. Exogenous tryptophan used by the gut microbes mainly originates from the undigested, or not fully digested, proteins, which are transferred from the small to the large intestine [ 10 ].…”

Section: The Amino Acid L-tryptophan Is Used By the Intestinal Microb...mentioning

confidence: 99%

“…[ 6 , 19 , 20 ]. Tryptophan can also be converted directly or indirectly by the intestinal microbiota into several indole-related compounds, including indole-3-pyruvate, indole-3-lactate, indole-3-propionate, indole-3-acetamide, indole-3-acrylate, indole acetaldehyde, indole-3-acetate, indole-3-aldehyde, 3-methyl-indole (skatole), and indole-3-acetaldehyde [ 5 , 18 , 21 , 22 , 23 , 24 ]. However, the precise metabolic pathways involved in the stepwise conversion of tryptophan into these minor indolic compounds by the intestinal microbiota in the large intestine remain unclear.…”

Section: The Amino Acid L-tryptophan Is Used By the Intestinal Microb...mentioning

confidence: 99%

“…In such a context, the present paper aims to provide the state of the art regarding the production from L-tryptophan of indole and indole-related compounds by the intestinal microbiota, the effects of indolic compounds on the intestinal mucosa, the metabolism of indole by the host, and the effects of indole and co-metabolites on peripheral organs. For the sake of clarity and concision, this review does not concern the effects on the host of other tryptophan-derived bacterial metabolites such as tryptamine, an inducer for the release of 5-hydroxytryptamine (serotonin) by enteroendocrine cells; this latter compound is able to stimulate gastrointestinal motility by acting on the neurons of the enteric nervous system, as detailed in recent reviews on that topic [ 4 , 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Production of Indole and Indole-Related Compounds by the Intestinal Microbiota and Consequences for the Host: The Good, the Bad, and the Ugly

2022

View full text Add to dashboard Cite

The intestinal microbiota metabolic activity towards the available substrates generates myriad bacterial metabolites that may accumulate in the luminal fluid. Among them, indole and indole-related compounds are produced by specific bacterial species from tryptophan. Although indole-related compounds are, first, involved in intestinal microbial community communication, these molecules are also active on the intestinal mucosa, exerting generally beneficial effects in different experimental situations. After absorption, indole is partly metabolized in the liver into the co-metabolite indoxyl sulfate. Although some anti-inflammatory actions of indole on liver cells have been shown, indoxyl sulfate is a well-known uremic toxin that aggravates chronic kidney disease, through deleterious effects on kidney cells. Indoxyl sulfate is also known to provoke endothelial dysfunction. Regarding the central nervous system, emerging research indicates that indole at excessive concentrations displays a negative impact on emotional behavior. The indole-derived co-metabolite isatin appears, in pre-clinical studies, to accumulate in the brain, modulating brain function either positively or negatively, depending on the doses used. Oxindole, a bacterial metabolite that enters the brain, has shown deleterious effects on the central nervous system in experimental studies. Lastly, recent studies performed with indoxyl sulfate report either beneficial or deleterious effects depending once again on the dose used, with missing information on the physiological concentrations that are reaching the central nervous system. Any intervention aiming at modulating indole and indole-related compound concentrations in the biological fluids should crucially take into account the dual effects of these compounds according to the host tissues considered.

show abstract

Blueberry extract for the treatment of ischaemic stroke through regulating the gut microbiota and kynurenine metabolism

Wang,

Huang,

et al. 2024

Phytotherapy Research

View full text Add to dashboard Cite

Although the gut microbiota and kynurenine (KYN) metabolism have significant protective effects against ischaemic stroke (IS), the exact mechanism has yet to be fully elucidated. Combined serum metabolomics and 16S rRNA gene sequencing were used to reveal the differences between the gut microbiota and metabolites in rats treated with or without blueberry extract. Faecal microbiota transplantation (FMT) was employed to validate the protective role of the gut microbiota in IS. Furthermore, the interaction between Prevotella and IS was also confirmed in patients. Rats with IS experienced neurological impairments accompanied by an impaired intestinal barrier and disturbed intestinal flora, which further contributed to heightened inflammatory responses. Furthermore, Prevotella played a critical role in IS pathophysiology, and a positive correlation between Prevotella and KYN was detected. The role of KYN metabolism in IS was further demonstrated by the finding that IDO was significantly upregulated and that the use of the IDO inhibitor, attenuated KYN metabolic pathway activity and ameliorated neurological damage in rats with IS. Prevotella intervention also significantly improved stroke symptoms and decreasing KYN levels in rats with IS. FMT showed that the beneficial effects of blueberry extract on IS involve gut bacteria, especially Prevotella, which were confirmed by microbiological analyses conducted on IS patients. Moreover, blueberry extract led to significant changes in kynurenic acid levels and tryptophan and IDO levels through interactions with Prevotella. Our study demonstrates for the first time that blueberry extract could modulate “intestinal microecology‐KYN metabolism” to improve IS.

show abstract

Emerging effects of tryptophan pathway metabolites and intestinal microbiota on metabolism and intestinal function

Cited by 52 publications

References 118 publications

Apex Predator Nematodes and Meso-Predator Bacteria Consume Their Basal Insect Prey through Discrete Stages of Chemical Transformations

Apex Predator Nematodes and Meso-Predator Bacteria Consume Their Basal Insect Prey through Discrete Stages of Chemical Transformations

Production of Indole and Indole-Related Compounds by the Intestinal Microbiota and Consequences for the Host: The Good, the Bad, and the Ugly

Blueberry extract for the treatment of ischaemic stroke through regulating the gut microbiota and kynurenine metabolism

Contact Info

Product

Resources

About