The oral maternal microbiome plays a role in the development of cleft lip and palate condition in children.

Non-syndromic cleft lip or palate (NS-CL/P) is an oral birth defect with complex aetiology. We compared the microbial diversity and composition of the oral microbiome of mothers of babies with NS-CL/P (CLP group) and mothers of babies without NS-CL/P (control group). Oral microbiome composition was determined by sequencing the V3-V4 regions of the 16S rRNA gene. CLP and control groups had overall similar microbial compositions, but significant differences were observed. The most significant microbial genus related to these differences was Cutibacterium, which was more abundant in the CLP group. Based on the literature, we hypothesize that a member of the Cutibacterium genus present in the oral microbiota may have a role in inflammation processes that could be related to NS-CL/P development. We found additional differences in terms of differential abundance when subsetting the dataset for mothers with a male child; in this case, depletion of Limosilactobacillus and an unknown taxon, in the CLP group, was a significant result. We conclude that the maternal oral microbiome likely plays a role in the development of the NS-CL/P condition.