In kids with obesity and metabolic issues, higher levels of a substance called d-lactate in the blood go hand-in-hand with more liver fat, belly fat, and unhealthy cholesterol patterns — suggesting a link between certain metabolic byproducts and liver problems.

What we've found so far is that higher levels of d-lactate in the blood are linked to increased liver fat, belly fat, and unhealthy cholesterol patterns in children with obesity and metabolic issues [1]. Our analysis of the available evidence currently leans toward a connection between this metabolic byproduct and markers of poor metabolic health in this group. We reviewed one key assertion based on 53.0 supporting studies, with no studies refuting the link [1]. This means that in children who have obesity and related metabolic problems, those with higher blood levels of d-lactate also tend to have more fat in the liver, more abdominal fat, and less healthy cholesterol levels. D-lactate is a compound produced by gut bacteria during the breakdown of certain foods, and its presence in the bloodstream may reflect changes in gut health or barrier function. Our current analysis does not prove that d-lactate causes these issues, nor do we claim it is the main driver of liver fat buildup. We are simply reporting what the evidence shows so far: a consistent pattern linking higher d-lactate levels to worse metabolic markers in children with obesity. Because we’ve only analyzed one assertion so far—albeit one backed by a substantial body of supporting studies—our understanding is still developing. We cannot yet say how strong this link is over time, or whether reducing d-lactate would improve health outcomes. For now, what this might mean for everyday life is that gut health could play a role in liver and metabolic health for children with obesity. We’re continuing to analyze more evidence to build a clearer picture over time.