Fig 1.
PRISMA flow diagram describing the literature search and article selection process.
a Detailed reasons for exclusion are provided in S3 Table.
Table 1.
Lactic acid-containing product details.
Table 2.
Key findings of included studies.
Fig 2.
+ indicates a low risk of bias, -/+ indicates moderate risk of bias,—indicates high risk of bias,? indicates unknown risk, NA indicates bias is not applicable to the study. a Other sources of bias include whether confounders were appropriately accounted for and whether lactic acid-containing product details were sufficiently described in the manuscript. b One study disclosed receipt of funding from the lactic acid-containing product manufacturer. c Single arm prospective cohort study.