Oxalaatafbraak

Oxalaatafbraak, or oxalate degradation, is the metabolic process by which oxalic acid (oxalate) is transformed into less harmful compounds. This occurs in a variety of organisms, most notably certain bacteria, fungi and plants, and can influence the levels of oxalate in the diet, fluids, and tissues.

In bacteria such as Oxalobacter formigenes, oxalate degradation proceeds via a pathway that activates oxalate to oxalyl-CoA, followed by decarboxylation to formyl-CoA and CO2. Formyl-CoA is then hydrolyzed to formate and CoA. This microbial route effectively reduces intestinal oxalate and can lower urinary oxalate excretion, with potential implications for kidney stone risk. Other microbes utilize enzymes such as oxalate decarboxylase, which converts oxalate directly to formate and CO2, or oxalate oxidase, which converts oxalate to CO2 and hydrogen peroxide. In plants and fungi, oxalate oxidase and related enzymes also participate in oxalate metabolism and defense responses.

In humans, endogenous oxalate degradation is limited; most oxalate is excreted by the kidneys, and only a small amount is metabolized within the body. The gut microbiome can influence systemic oxalate levels, and the presence or absence of oxalate-degrading bacteria has been linked to variations in urinary oxalate and kidney stone risk.

Applications of oxalate-degrading systems include bioremediation of oxalate-rich waste streams, processing strategies to reduce dietary oxalate content, and probiotic approaches aimed at modifying host oxalate balance. Research continues to clarify the abundance, regulation, and health impact of oxalate-degrading microbes in humans and other ecosystems.