Para-Hydroxyphenyllactate

High levels of para-hydroxyphenyllactate may occur when there are nutritional enzyme inhibitions of the breakdown pathways, inherited low-activity enzymes are present, or if there are high levels of precursors (tyrosine). Para-hydroxyphenyllactate is broken down by sulfotransferase and glucuronidase enzymes that are important for balancing hormone levels. If the diet is high in protein or plant materials (polyphenols) or if tyrosine supplements are being used, para-hydroxyphenyllactate may be produced by the gut microbiome which can also increase circulating levels of para-hydroxyphenyllactate. A gut microbiome dysbiosis may also increase levels.

Enzyme inhibition of sulfotransferase enzymes SULT1A3 and SULT2B1 may also increase levels of vanilmandelate. Consider supporting sulfotransferase enzymes with iron (if deficient) and molybdenum. Support glucuronidation enzymes UGTA1 with its substrate calcium-D-glucarate, and glycyrrhizin (Glycyrrhiza glabra or licorice root). Licorice or glycyrrhizin may be contraindicated if the patient has high blood pressure.

Low levels of para-hydroxyphenyllactate may occur if there are low levels of precursors (tyrosine), if there are nutritional enzyme inhibitions, or if a low-activity enzyme variant is inherited. Liver disorders that prevent the breakdown of tyrosine may also result in low levels; if this occurs circulating levels of tyrosine and its precursor phenylalanine may increase. Some of the para-hydroxyphenyllactate in circulation may be the result of protein breakdown by the gut microbiome; a loss of beneficial bacteria could possibly contribute to lower levels.

- The synthesis pathway for para-hydroxyphenyllactate is vitamin B6 and iron-dependent. Low levels may indicate a nutritional deficiency of these cofactors.

- Low levels of the essential amino acid phenylalanine and/or tyrosine may occur if there are problems with protein digestion and assimilation. Levels of vanilmandelate, homovanillate, 5-hydroxyindoleacetate, 2-hydroxyphenylacetate, para-hydroxyphenylacetate, and para-hydroxybenzoate may also be low.

- Low levels of beneficial bacteria in the gut microbiome (insufficiency dysbiosis) may occur due to antibiotic use, psychological stress, etc. If an insufficiency dysbiosis is present, then the majority of the Markers of Bacterial Metabolism may also be lower than expected. Environmental or psychological stress can increase levels of vanilmandelate, homovanillate, 5-hydroxyindoleacetate, para hydroxyphenyllactate, and hippurate.

p-hydroxyphenyllactate is a marker of cell turnover. It is also a metabolite in tyrosine degradation and may be useful for studying disorders of tyrosine metabolism.