Tryptophan is an essential amino acid critical for protein synthesis in humans that has
emerged as a key player in the microbiota-gut-brain axis. It is the only precursor for the …

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 …

Regulatory and functional aspects of the kynurenine (K) pathway (KP) of tryptophan (Trp)
degradation are reviewed. The KP accounts for~ 95% of dietary Trp degradation, of which …

Neuroactive compounds are synthesized by certain plants and microorganisms by
undertaking different tasks, especially as a stress response. Most common neuroactive …

Nicotinamide adenine dinucleotide (NAD+) is a co-substrate for several enzymes, including
the sirtuin family of NAD+-dependent protein deacylases. Beneficial effects of increased …

The 'microbiota-gut-brain axis' plays a fundamental role in maintaining host homeostasis,
and different immune, hormonal, and neuronal signals participate to this interkingdom …

Myalgic encephalomyelitis (ME) or Chronic Fatigue Syndrome (CFS) is a neglected,
debilitating multi-systemic disease without diagnostic marker or therapy. Despite evidence …

Tryptophan (TRP), an essential amino acid in mammals, is involved in several physiological
processes including neuronal function, immunity, and gut homeostasis. In humans, TRP is …

We survey the historical development of scientific knowledge surrounding Vitamin B3, and
describe the active metabolite forms of Vitamin B3, the pyridine dinucleotides NAD+ and …

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 …