Dynamic construction of gut microbiota may influence allergic diseases of infants in Southwest China

Abstract

Background: Gut microbes have been suggested as the possible targets in the management of allergic diseases. However, the way in which these microbes influence allergic diseases remain unclear. Forty-seven full-term newborns were selected from a 1000-infant birth cohort. Among them were 23 allergic infants, whereas 24 infants were healthy without allergic symptoms at 1 year of age. Two hundred and sixty-four fecal samples were collected at 7 time points following their birth. These fecal samples were microbiologically analyzed using 16S rRNA gene sequencing. The dynamic processes involved in gut microbiota diversity and composition in the tested infants were constructed.

Results: Healthy infants demonstrated more statistical differences in longitudinal changes in the alpha diversity of their microbiota at the time points compared with day 0 (meconium) than did allergic infants. Analysis of beta diversity showed that the fecal microbiota of days 0 and 2 comprised different communities in healthy infants, and that there were three separate communities in the fecal microbiota of day 0 of the healthy infants, those of day 2 of the healthy infants, and those of days 0-2 of the allergic infants. The relative abundance of dominant gut microbiota at phylum level varied at different time points in the healthy and diseased groups. Bifidobacterium, Escherichia-Shigella, Streptococcus, Clostridium_sensu_stricto_1, Akkermansia and Erysipelatoclostridium were significantly different between the healthy and diseased groups at a different time points.

Conclusion: The dynamic construction processes of gut microbiota during early life might be associated with the occurrence of long-term allergic diseases, with the first month following birth potentially being the most critical.

Keywords: Allergic diseases; Dynamic process; Gastrointestinal microbiome; High-throughput nucleotide sequencing; Infant; RNA,Ribosomal,16S.

Fig. 1

Differences in variation over time of alpha diversity between healthy and diseased groups using different measure indexes. Ace, Chao1 and Observed OTUs indexes reflect species richness, and Shannon or Simpson indexes reflect species diversity. a, b, c, d, e Kruskal-wallis test was used for analysing differences among time groups in the healthy and diseased groups, respectively. Values are presented as mean ± S.E.M. * P < 0.05 compared to day 0 samples

Fig. 2

Beta diversity of day 0, day2 and month 12. PLS-DA was carried out according to time group, and the results reflect beta diversity which present differences in community structure between time groups. a Samples of day 0 (meconium), day 2 and month 12 were divided into three different communities. b Day 0 samples (meconium) of the healthy group, day 2 samples of the healthy group and day 0 to day 2 samples of the diseased group were divided into three different communities

Fig. 3

Composition of gut microbiota at the phylum level varied over time in healthy and diseased groups. Phyla with the relative abundance of more than 1% are presented, and the lower abundant phyla are grouped as ‘Others

Fig. 4

a, b, c, d, e, f Dominant microbiota at the phylum level varied over time in healthy and diseased groups. Kruskal-wallis test was used for analysing differences among time groups in the healthy and diseased groups, respectively. Values are presented as mean ± S.E.M. * P < 0.05 compared to samples of the time point

Fig. 5

Bacteroidetes/Firmicutes ratio. Bacteroidetes/Firmicutes ratio of month 1 samples was significantly higher than that of day 0 samples (meconium) in healthy group. Month 1 samples in healthy group, 1.06; day 0 samples (meconium) in healthy group, 0.55. * P < 0.05 compared to samples of day 0 in healthy group