Butyric acid (butanoic acid) belongs to a group of short-chain fatty acids and is thought to play several beneficial roles in the gastrointestinal tract. The butyric anion is easily absorbed by enteric cells and used as a main source of energy. Moreover, butyric acid is an important regulator of colonocyte proliferation and apoptosis, gastrointestinal tract motility and bacterial microflora composition in addition to its involvement in many other processes including immunoregulation and anti-inflammatory activity. Butyric acid shows a protective effect in inflammatory response secondary to inflammatory bowel diseases. A beneficial effect of butyric acid as one constituent of a multifaceted mechanism modulating gastrointestinal function has also been stressed in patients with the stoma and coexisting constipation. Butyric acid supplementation combined with the use of probiotics should be adopted as one of the basic therapeutic strategies in this patient group, preceding treatment with laxatives. Sodium butyrate in the form of enemas (combined in a mixture with A-300 silicon dioxide) may be a successful method of therapeutic management in patients with radiation proctitis. Sodium butyrate may also prevent diarrhea through an increased passive absorption of water in the colon and its effects on the gut microflora.

Pyridoxal is a pyridinecarbaldehyde and a form of vitamin B 6 which is converted to pyridoxal phosphate. Pyridoxal 5'-phosphate is involved in a wide range of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemoglobin, sphingomyelin, and other sphingolipids, and the synthesis of the neurotransmitters serotonin, dopamine, norepinephrine and gamma-aminobutyric acid (GABA). Pyridoxal is one of the natural forms available of vitamin B6, therefore, it is used for nutritional supplementation and for treating dietary shortage or imbalances. Some medically relevant bacteria, such as those in the genera Granulicatella and Abiotrophia, require pyridoxal for growth. This nutritional requirement can lead to the culture phenomenon of satellite growth. In in vitro culture, these pyridoxal-dependent bacteria may only grow in areas surrounding colonies of bacteria from other genera ("satellitism") that are capable of producing pyridoxal.

Beta-alanine is an endogenous agonist of glycine receptor, which is used a supplementation among competitive athletes participating in a range of different sports. Beta-alanine has been shown to enhance muscular endurance and its supplementation appears to be most effective for exercise tasks that rely heavily on ATP synthesis from anaerobic glycolysis.

Retinal, All-trans is one of the forms of vitamin A. It is an isomer of 11-cis-retinal, transductor of light into the neural signals. Retinal, All-trans is converted to retinoic acid in vivo by the action of retinal dehydrogenase. Retinal, All-trans is associated with one of the two isoforms of cellular retinol-binding proteins (CRBP-I and CRBP-II). These proteins play important roles in retinoid biology and regulation of the metabolism of retinol and retinal.

Bilirubin is an orange-yellow pigment made during the normal breakdown of red blood cells. Bilirubin passes through the liver and is excreted out of the body. Occasionally, higher bilirubin levels may indicate an increased rate of destruction of red blood cells (hemolysis). A high level of bilirubin in the blood is called hyperbilirubinemia. High bilirubin levels can cause jaundice. Jaundice makes the skin and the whites of the eyes appear yellow, due to the brown and yellow bilirubin in the blood. Phototherapy for neonatal is one of the treatment methods against hyperbilirubinemia. Light absorption by bilirubin in the skin transforms the native Z,Z-bilirubin to conformational photoisomers Z,E-bilirubin and E,Z-bilirubin and structural photoisomers E,Z-lumirubin and E,E-lumirubin. Formation and excretion of Z,E-bilirubin and E,Z-lumirubin are both important routes of elimination of bilirubin through bile and urine, although the precise contributions of the various photoisomers to the overall elimination of bilirubin are still unknown.

Lanosterol represents the first step in sterol formation and can be converted by lanosterol 14 α-demethylase (CYP51, a member of the cytochrome P450 family), to follicular fluid meiosis activating factor (FF-MAF), a sterol intermediate that has been extensively studied and shown to activate meiosis in gametes. Lanosterol modulates TLR4-mediated innate immune responses in macrophages. Lanosterol accumulation increases membrane fluidity and ROS production, thus potentiating phagocytosis and the ability to kill bacteria. Preliminary studies in dogs and rabbits have shown that lanosterol can prevent and even reverse cataract formation. However, Lanosterol 25 mM solution did not reverse opacification of human age-related cataractous nuclei. Lanosterol induces mitochondrial uncoupling and protects dopaminergic neurons from cell death in a model for Parkinson's disease.

Trimethylamine (or TMA) a tertiary amine, is synthesized by the action of microbial enzymes in humans. The decrease of TMA metabolism and excessive TMA excretion cause the disease trimethylaminuria and some other diseases associated with the abnormal level of TMA, e.g., obesity, diabetes, cardiovascular diseases. It was shown, that TMS is a full agonist of human trace amine-associated receptor 5, TAAR5. In addition, TMA is a precursor of N-oxide form, an emergent biomarker of human health that can lead to renal diseases, neurological disorders, and cancer.