Lactobacillus plantarum is a probiotic bacterium commonly found in fermented foods and used in dietary supplements. Its use for supporting or treating lactose intolerance is supported by some scientific rationale, though the evidence is limited and not as robust as for other probiotics like Lactobacillus acidophilus or Bifidobacterium species.

The proposed mechanism is that certain strains of L. plantarum can produce the enzyme β-galactosidase (lactase), which aids in the breakdown of lactose in the gut. In vitro and animal studies have demonstrated that L. plantarum can exhibit lactase activity and may help hydrolyze lactose, potentially alleviating symptoms of lactose intolerance. However, human clinical trials specifically evaluating L. plantarum for lactose intolerance are sparse.

Most clinical research on probiotics for lactose intolerance has focused on other species. Some multi-strain probiotic supplements that include L. plantarum have shown mild improvements in lactose digestion and reduction of symptoms, but the individual contribution of L. plantarum is unclear. Systematic reviews and meta-analyses typically do not cite strong evidence for L. plantarum alone in this context.

In summary, while there is a scientific basis for the use of L. plantarum in supporting lactose digestion, the direct human evidence is limited, and the overall strength of evidence is moderate to low.