BACKGROUND The essential amino acid tryptophan is a substrate for the generation of
several bioactive compounds with important physiological roles. Only a small fraction of …

Tryptophan catabolism through the kynurenine pathway generates a variety of bioactive
metabolites. Physical exercise can modulate kynurenine pathway metabolism in skeletal …

Tryptophan is an essential amino acid that can be metabolised through different pathways, a
major route being the kynurenine pathway. The first enzyme of the pathway, indoleamine-2 …

The kynurenine pathway is important in cellular energy generation and limiting cellular
ageing as it degrades about 90% of dietary tryptophan into the essential co-factor NAD+ …

Research on the neurobiology of the kynurenine pathway has suffered years of relative
obscurity because tryptophan degradation, and its involvement in both physiology and major …

Kynurenic acid (KYNA), a metabolite of tryptophan, is an endogenous substance produced
intracellularly by various human cells. In addition, KYNA can be synthesized by the gut …

The essential amino acid tryptophan is not only a precursor of serotonin but is also
degraded to several other neuroactive compounds, including kynurenic acid, 3 …

The tryptophan–kynurenine pathway (Trp–KYN) is the major route for tryptophan conversion
in the brain and in the periphery. Kynurenines display a wide range of biological actions …

Tryptophan (Trp) availability for the kynurenine pathway (KP) across the life span is
discussed. Free (non-albumin-bound) plasma Trp is the major determinant of the flux of Trp …

It has become increasingly clear that the gut microbiota influences not only gastrointestinal
physiology but also central nervous system (CNS) function by modulating signalling …