Unravelling the Gut Microbiota of Cow’s Milk Allergic Infants, Their Mothers and Grandmothers

Abstract Background: Cow’s Milk Allergy (CMA) is one of the most prevalent food allergies (FA) among infants. Gut microbiota dysbiosis has been related to the development of FA. The primary colonization of the gut microbiota occurs via maternal route. We hypothesized that a longitudinal influence in the composition of the gut microbiota, transmitted from mothers to offspring, could be directly related to CMA development. Methods: 148 faecal samples of 34 CMA and 16 control 0-8 month-old infants and their respective mothers and grandmothers were studied. Gut microbiota was profiled by 16S rRNA gene sequencing using the Illumina MiSeq platform. 16S rRNA sequencing analysis was performed using the DADA2 pipeline. Descriptive statistics of the epidemiological variables of the three generations were analysed. Statistical analyses were performed with R 3.4.0 software. Results : Mothers allergy status and smoking habits of mothers and grandmothers were associated to infant CMA. We found that adult gut microbiota is richer and more diverse than that of infants. Relative abundance of the Prevotellaceae family was significantly different between infant groups, and between hydrolysate-fed and formula-fed infants. Finally, the Bray-Curtis distance between members of the same family was independent of the allergy status. Conclusions: Microbiota from allergic children do not differ from non-allergic at the onset of allergy. Moreover, microbiota inheritance was similar in healthy and allergic infants. Maternal smoking and allergy status were the most significant epidemiological risk factors associated with CMA. Finally, microbiota composition of infants was influenced by diet and allergy status; however, these were confounded variables.