Bifidobacterium bifidum TMC3115 ameliorates milk protein allergy in by affecting gut microbiota: A randomized double-blind control trial

We aimed to explore the effects of Bifidobacterium bifidum TMC3115 intervention on cow's milk protein allergy (CMPA) and gut microbiota in infants. A total 256 CMPA infants were randomly and evenly assigned into an intervention group (B. bifidum) and a control group (placebo). Allergic scores, anti-inflammatory responses, and secondary outcomes were measured. Fecal specimens were collected, and the gut microbiota were analyzed by using 16S rDNA sequencing. After 6-month B. bifidum intervention, B. bifidum TMC3115 consumption reduced allergic scores, and improved anti-inflammatory responses and secondary outcomes in CMPA infants. LEfSe analysis showed Bifidobacterium, Lactobacillus, Turicibacter, Sutterella, and Parabacteroides were the most predominant phylum in the intervention group, whereas the Firmicutes (Anaerovibrio, Christensenellaceae, Oscillibacter, Bilophila, Dorea, and Roseburia) were most dominant phyla in the control group. Serum IgE or IgG2 had a strong relationship with α-diversity scores of gut microbiota. PRACTICAL APPLICATIONS: There is a high level of prevalence of milk allergy in infants, which is difficult to be treated. Bifidobacterium bifidum TMC3115 supplement reduced allergic scores, improved anti-inflammatory responses, and reduced serum level of IgE and increased the level of IgG2 in the infants. On the contrary, B. bifidum supplement increased the genus proportion of probiotics and reduced the proportion of pathogens. The improvement of gut microbiota will be beneficial in the prevention of milk allergy. B. bifidum TMC3115 reduces milk allergy in the infants by regulating gut microbiota, and should be developed a potential way in the prevention of infant milk allergy.