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Having older siblings is associated with gut microbiota development during early childhood.

Laursen MF, Zachariassen G, Bahl MI, Bergström A, Høst A, Michaelsen KF, Licht TR - BMC Microbiol. (2015)

Bottom Line: Gut microbiota characteristics were not significantly associated with cumulative occurrence of eczema and asthmatic bronchitis during the first 3 years of life.Presence of older siblings is associated with increased gut microbial diversity and richness during early childhood, which could contribute to the substantiation of the hygiene hypothesis.However, no associations were found between gut microbiota and atopic symptoms of eczema and asthmatic bronchitis during early childhood and thus further studies are required to elucidate whether sibling-associated gut microbial changes influence development of allergies later in childhood.

View Article: PubMed Central - PubMed

Affiliation: Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860, Søborg, Denmark. mfrla@food.dtu.dk.

ABSTRACT

Background: Evidence suggests that early life infections, presence of older siblings and furred pets in the household affect the risk of developing allergic diseases through altered microbial exposure. Recently, low gut microbial diversity during infancy has also been linked with later development of allergies. We investigated whether presence of older siblings, furred pets and early life infections affected gut microbial communities at 9 and 18 months of age and whether these differences were associated with the cumulative prevalence of atopic symptoms of eczema and asthmatic bronchitis at 3 years of age. Bacterial compositions and diversity indices were determined in fecal samples collected from 114 infants in the SKOT I cohort at age 9 and 18 months by 16S rRNA gene sequencing. These were compared to the presence of older siblings, furred pets and early life infections and the cumulative prevalence of diagnosed asthmatic bronchitis and self-reported eczema at 3 years of age.

Results: The number of older siblings correlated positively with bacterial diversity (p = 0.030), diversity of the phyla Firmicutes (p = 0.013) and Bacteroidetes (p = 0.004) and bacterial richness (p = 0.006) at 18 months. Further, having older siblings was associated with increased relative abundance of several bacterial taxa at both 9 and 18 months of age. Compared to the effect of having siblings, presence of household furred pets and early life infections had less pronounced effects on the gut microbiota. Gut microbiota characteristics were not significantly associated with cumulative occurrence of eczema and asthmatic bronchitis during the first 3 years of life.

Conclusions: Presence of older siblings is associated with increased gut microbial diversity and richness during early childhood, which could contribute to the substantiation of the hygiene hypothesis. However, no associations were found between gut microbiota and atopic symptoms of eczema and asthmatic bronchitis during early childhood and thus further studies are required to elucidate whether sibling-associated gut microbial changes influence development of allergies later in childhood.

No MeSH data available.


Related in: MedlinePlus

Correlation matrices relating relative abundance of bacterial genera at 9 months (a) and 18 months (b) to the presence of older siblings, furred pets and early life infections. Scale indicate the Spearman’s rank correlation coefficient rho, ranging from −0.5 (negative correlation; red color) to 0.5 (positive correlation; blue color). Black dots indicate statistically significant correlations with FDR adjusted p-value < 0.1
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Fig3: Correlation matrices relating relative abundance of bacterial genera at 9 months (a) and 18 months (b) to the presence of older siblings, furred pets and early life infections. Scale indicate the Spearman’s rank correlation coefficient rho, ranging from −0.5 (negative correlation; red color) to 0.5 (positive correlation; blue color). Black dots indicate statistically significant correlations with FDR adjusted p-value < 0.1

Mentions: To minimize confounding effects, we confirmed that prevalence of allergic heredity and C-section, average gestational age at birth, actual age at 9 and 18 month visits, infant age at start of daycare or nursery, breastfeeding duration and macronutrient intake at 9 and 18 months visits were similar between infants with and without older siblings, furred pets or early life infections (Additional file 2: Table S2). Alpha diversity and richness of the gut microbial populations were calculated for all individuals at ages 9 and 18 months, and these data were compared between infants with and without older siblings, furred pets and early life infections (Fig. 1). Infants with older siblings in the household had a higher bacterial diversity (p = 0.045) and richness (p = 0.009) at 18, but not at 9 months of age compared to infants with no older siblings (Fig. 1a, b). In addition, significant correlations between the specific number of older siblings (0, 1 or >2) and bacterial diversity (p = 0.030) or richness (p = 0.006) were found (Fig. 2a, b). Specifically, the phyla diversity within Firmicutes (p = 0.013) and Bacteroidetes at age 18 months (p = 0.004) were positively correlated with numbers of older siblings (Fig. 2c, d), while phyla diversity within Actinobacteria and Proteobacteria were not affected (data not shown). Presence of furred pets in the household did not affect bacterial diversity or richness of the total gut microbial populations at 9 or 18 months (Fig. 1c, d). However, infants with furred pets had lower diversity (p = 0.010) within the Firmicutes phylum at 9 months (data not shown). Infants with registered history of early life infections had a lower bacterial diversity (p = 0.067) and richness (p = 0.023) at age 18 months, but not at age 9 months (Fig. 1e, f). Investigation of associations between abundances of specific microbial genera and the presence of older siblings, furred pets or early life infections (Fig. 3) revealed that Haemophilus and Faecalibacterium abundance at age 9 months were significantly positively associated with the presence of older siblings, while this was true for Barnesiella, Odoribacter, Asaccharobacter and Gondonibacter at age 18 months. The presence of furred pets was positively associated only with Cronobacter abundance at 18 months of age. Early life infections were not significantly associated with any specific gut microbial genera after adjustment for multiple testing. However, we note that Haemophilus abundance at 9 months was positively associated (non-adjusted p = 0.019) with early life infections (Additional file 3: Figure S1).Fig. 1


Having older siblings is associated with gut microbiota development during early childhood.

Laursen MF, Zachariassen G, Bahl MI, Bergström A, Høst A, Michaelsen KF, Licht TR - BMC Microbiol. (2015)

Correlation matrices relating relative abundance of bacterial genera at 9 months (a) and 18 months (b) to the presence of older siblings, furred pets and early life infections. Scale indicate the Spearman’s rank correlation coefficient rho, ranging from −0.5 (negative correlation; red color) to 0.5 (positive correlation; blue color). Black dots indicate statistically significant correlations with FDR adjusted p-value < 0.1
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4522135&req=5

Fig3: Correlation matrices relating relative abundance of bacterial genera at 9 months (a) and 18 months (b) to the presence of older siblings, furred pets and early life infections. Scale indicate the Spearman’s rank correlation coefficient rho, ranging from −0.5 (negative correlation; red color) to 0.5 (positive correlation; blue color). Black dots indicate statistically significant correlations with FDR adjusted p-value < 0.1
Mentions: To minimize confounding effects, we confirmed that prevalence of allergic heredity and C-section, average gestational age at birth, actual age at 9 and 18 month visits, infant age at start of daycare or nursery, breastfeeding duration and macronutrient intake at 9 and 18 months visits were similar between infants with and without older siblings, furred pets or early life infections (Additional file 2: Table S2). Alpha diversity and richness of the gut microbial populations were calculated for all individuals at ages 9 and 18 months, and these data were compared between infants with and without older siblings, furred pets and early life infections (Fig. 1). Infants with older siblings in the household had a higher bacterial diversity (p = 0.045) and richness (p = 0.009) at 18, but not at 9 months of age compared to infants with no older siblings (Fig. 1a, b). In addition, significant correlations between the specific number of older siblings (0, 1 or >2) and bacterial diversity (p = 0.030) or richness (p = 0.006) were found (Fig. 2a, b). Specifically, the phyla diversity within Firmicutes (p = 0.013) and Bacteroidetes at age 18 months (p = 0.004) were positively correlated with numbers of older siblings (Fig. 2c, d), while phyla diversity within Actinobacteria and Proteobacteria were not affected (data not shown). Presence of furred pets in the household did not affect bacterial diversity or richness of the total gut microbial populations at 9 or 18 months (Fig. 1c, d). However, infants with furred pets had lower diversity (p = 0.010) within the Firmicutes phylum at 9 months (data not shown). Infants with registered history of early life infections had a lower bacterial diversity (p = 0.067) and richness (p = 0.023) at age 18 months, but not at age 9 months (Fig. 1e, f). Investigation of associations between abundances of specific microbial genera and the presence of older siblings, furred pets or early life infections (Fig. 3) revealed that Haemophilus and Faecalibacterium abundance at age 9 months were significantly positively associated with the presence of older siblings, while this was true for Barnesiella, Odoribacter, Asaccharobacter and Gondonibacter at age 18 months. The presence of furred pets was positively associated only with Cronobacter abundance at 18 months of age. Early life infections were not significantly associated with any specific gut microbial genera after adjustment for multiple testing. However, we note that Haemophilus abundance at 9 months was positively associated (non-adjusted p = 0.019) with early life infections (Additional file 3: Figure S1).Fig. 1

Bottom Line: Gut microbiota characteristics were not significantly associated with cumulative occurrence of eczema and asthmatic bronchitis during the first 3 years of life.Presence of older siblings is associated with increased gut microbial diversity and richness during early childhood, which could contribute to the substantiation of the hygiene hypothesis.However, no associations were found between gut microbiota and atopic symptoms of eczema and asthmatic bronchitis during early childhood and thus further studies are required to elucidate whether sibling-associated gut microbial changes influence development of allergies later in childhood.

View Article: PubMed Central - PubMed

Affiliation: Division of Diet, Disease Prevention and Toxicology, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860, Søborg, Denmark. mfrla@food.dtu.dk.

ABSTRACT

Background: Evidence suggests that early life infections, presence of older siblings and furred pets in the household affect the risk of developing allergic diseases through altered microbial exposure. Recently, low gut microbial diversity during infancy has also been linked with later development of allergies. We investigated whether presence of older siblings, furred pets and early life infections affected gut microbial communities at 9 and 18 months of age and whether these differences were associated with the cumulative prevalence of atopic symptoms of eczema and asthmatic bronchitis at 3 years of age. Bacterial compositions and diversity indices were determined in fecal samples collected from 114 infants in the SKOT I cohort at age 9 and 18 months by 16S rRNA gene sequencing. These were compared to the presence of older siblings, furred pets and early life infections and the cumulative prevalence of diagnosed asthmatic bronchitis and self-reported eczema at 3 years of age.

Results: The number of older siblings correlated positively with bacterial diversity (p = 0.030), diversity of the phyla Firmicutes (p = 0.013) and Bacteroidetes (p = 0.004) and bacterial richness (p = 0.006) at 18 months. Further, having older siblings was associated with increased relative abundance of several bacterial taxa at both 9 and 18 months of age. Compared to the effect of having siblings, presence of household furred pets and early life infections had less pronounced effects on the gut microbiota. Gut microbiota characteristics were not significantly associated with cumulative occurrence of eczema and asthmatic bronchitis during the first 3 years of life.

Conclusions: Presence of older siblings is associated with increased gut microbial diversity and richness during early childhood, which could contribute to the substantiation of the hygiene hypothesis. However, no associations were found between gut microbiota and atopic symptoms of eczema and asthmatic bronchitis during early childhood and thus further studies are required to elucidate whether sibling-associated gut microbial changes influence development of allergies later in childhood.

No MeSH data available.


Related in: MedlinePlus