RETRACTED: Effect of Bifidobacterium bifidum Supplementation in Newborns Born from Cesarean Section on Atopy, Respiratory Tract Infections, and Dyspeptic Syndromes: A Multicenter, Randomized, and Controlled Clinical Trial

Abstract

Cesarean section is considered a possible trigger of atopy and gut dysbiosis in newborns. Bifidobacteria, and specifically B. bifidum, are thought to play a central role in reducing the risk of atopy and in favoring gut eubiosis in children. Nonetheless, no trial has ever prospectively investigated the role played by this single bacterial species in preventing atopic manifestations in children born by cesarean section, and all the results published so far refer to mixtures of probiotics. We have therefore evaluated the impact of 6 months of supplementation with B. bifidum PRL2010 on the incidence, in the first year of life, of atopy, respiratory tract infections, and dyspeptic syndromes in 164 children born by cesarean (versus 249 untreated controls). The results of our multicenter, randomized, and controlled trial have shown that the probiotic supplementation significantly reduced the incidence of atopic dermatitis, upper and lower respiratory tract infections, and signs and symptoms of dyspeptic syndromes. Concerning the gut microbiota, B. bifidum supplementation significantly increased α-biodiversity and the relative values of the phyla Bacteroidota and Actinomycetota, of the genus Bacteroides, Bifidobacterium and of the species B. bifidum and reduced the relative content of Escherichia/Shigella and Haemophilus. A 6-month supplementation with B. bifidum in children born by cesarean section reduces the risk of gut dysbiosis and has a positive clinical impact that remains observable in the following 6 months of follow-up.

Keywords: 16S rRNA; ITS; children; dyspepsia; microbiota analysis; probiotics.

Figure 1

Infants enrolled and lost during follow-up. All patients who did not comply with the protocol were progressively excluded from this study. The reasons for the exclusions are reported in Supplementary Table S1.

Figure 2

Graphic representations at phylum level of gut microbiota of infants of the probiotic-treated group (Group A) at enrolment (left) and after 6 months of treatment (right). Significant differences concern the phyla Actinomycetota (former Actinobacteria) and Bacteroidota (former Bacteroidetes), which both increased after 6 months of treatment versus enrolment, and Pseudomonadota (former Proteobacteria), which reduced at 6 months versus enrolment. Verrucomicrobiota, Mycoplasmatota, Fusobacteriota, and Bacillota are the new phyla names, respectively, for Verrucomicrobia, Tenericutes, Fusobacteria, and Firmicutes. ASV: amplicon sequence variant.

Figure 3

Graphic representations at phylum level of gut microbiota of infants of the control group (Group B) at 6 months of life (left) and of the probiotic group (Group A) after 6 months of treatment (right). Significant differences concern the phylum Pseudomonadota (former Proteobacteria), which reduced in the probiotic group versus control. A tendential but not significant difference is also observed in the phyla Actinomycetota (former Actinobacteria) and Bacteroidota (former Bacteroidetes), and in biodiversity, both are more expressed in the group treated with the probiotic versus controls. Verrucomicrobiota, Mycoplasmatota, Fusobacteriota, and Bacillota are the new phyla names, respectively, for Verrucomicrobia, Tenericutes, Fusobacteria, and Firmicutes. ASV: amplicon sequence variant.