Abstract:

Objective To dynamically monitor and analyze infants with cow’s milk protein allergy (CMPA), milk protein tolerance and changes in gut microbiome during clinical treatment. Methods Fifty infants with CMPA attended the pediatric outpatient clinic were selected as the CMPA group, and 20 infants underwent health checkups were selected as the healthy control groupat the Child Health Development Center of Peking University Third Hospital from September 2020 to March 2021. The differences in gut microbiome between the two groups were compared. Results There were 50 patients in the CMPA group, including 21 males and 29 females, with a median age of 4 months. The control group consisted of 20 cases, of 12 males and 8 females, with a median age of 4 months. There were no statistically significant differences between the CMPA group and the control group in terms of age inmonths, sex, birth mass, mode of delivery, and feeding mode (all P>0.05). The baseline data of the children in the two groups were comparable. Follow-up of treatment and regression of children in the CMPA group at months 1, 3, and 6 revealed that a total of 38 children had established immune tolerance by 6 months, and 12 others still had CMPA. The Shannon index and Shannoneven index were statistically higher in the CMPA group compared with the control group (P<0.05), and the Anosim test showed statistically significant differences in community composition between the two sample groups (R=0.26, P=0.001). The relative abundance of Actinobacteria was significantly lower in the CMPA group. The relative abundance of Firmicutes was higher in the tolerant group than in the allergic group after six months of follow-up. During the treatment of CMPA-tolerant infants, species with progressively higher abundance were observed for Bifidobacterium (P<0.01), Blautia (P<0.01), Ruminococcus (P<0.01) and Faecalibacterium (P<0.01). Except for Bifidobacterium, all other species were known as butyrate producers. Conclusion The gut microbiome of children with CMPA differs from that of healthy children. The relative abundance of Bifidobacterium and butyrate-producers microbiome in the intestine of children with CMPA was increased during the establishment of immune tolerance.

Key words: cow’s milk protein allergy, gut microbiome, 16S rRNA high-throughput sequencing, Bifidobacterium