TY - JOUR
T1 - Long-term biodiversity intervention shapes health-associated commensal microbiota among urban day-care children
AU - Roslund, Marja I.
AU - Puhakka, Riikka
AU - Nurminen, Noora
AU - Oikarinen, Sami
AU - Siter, Nathan
AU - Grönroos, Mira
AU - Cinek, Ondřej
AU - Kramná, Lenka
AU - Jumpponen, Ari
AU - Laitinen, Olli H.
AU - Rajaniemi, Juho
AU - Hyöty, Heikki
AU - Sinkkonen, Aki
AU - the ADELE research group
N1 - Funding Information:
Funding: The funding was provided by Business Finland (grant numbers 40333/14 and 6766/31/2017) and the Helsinki Metropolitan Region Urban Research Program (Finland).
Funding Information:
The authors wish to acknowledge the children and their parents/guardians, the day-care personnel, and the cities of Espoo, Lahti, and Tampere for enabling the study. The authors also acknowledge the CSC ? IT Center for Science, Finland, for computational resources, the ADELE team members and AlmaLab for their support, and three reviewers for critical comments.
Publisher Copyright:
© 2021
PY - 2021
Y1 - 2021
N2 - Background: In modern urban environments children have a high incidence of inflammatory disorders, including allergies, asthma, and type 1 diabetes. The underlying cause of these disorders, according to the biodiversity hypothesis, is an imbalance in immune regulation caused by a weak interaction with environmental microbes. In this 2-year study, we analyzed bacterial community shifts in the soil surface in day-care centers and commensal bacteria inhabiting the mouth, skin, and gut of children. We compared two different day-care environments: standard urban day-care centers and intervention day-care centers. Yards in the latter were amended with biodiverse forest floor vegetation and sod at the beginning of the study. Results: Intervention caused a long-standing increase in the relative abundance of nonpathogenic environmental mycobacteria in the surface soils. Treatment-specific shifts became evident in the community composition of Gammaproteobacteria, Negativicutes, and Bacilli, which jointly accounted for almost 40 and 50% of the taxa on the intervention day-care children's skin and in saliva, respectively. In the year-one skin swabs, richness of Alpha-, Beta-, and Gammaproteobacteria was higher, and the relative abundance of potentially pathogenic bacteria, including Haemophilus parainfluenzae, Streptococcus sp., and Veillonella sp., was lower among children in intervention day-care centers compared with children in standard day-care centers. In the gut, the relative abundance of Clostridium sensu stricto decreased, particularly among the intervention children. Conclusions: This study shows that a 2-year biodiversity intervention shapes human commensal microbiota, including taxa that have been associated with immune regulation. Results indicate that intervention enriched commensal microbiota and suppressed the potentially pathogenic bacteria on the skin. We recommend future studies that expand intervention strategies to immune response and eventually the incidence of immune-mediated diseases.
AB - Background: In modern urban environments children have a high incidence of inflammatory disorders, including allergies, asthma, and type 1 diabetes. The underlying cause of these disorders, according to the biodiversity hypothesis, is an imbalance in immune regulation caused by a weak interaction with environmental microbes. In this 2-year study, we analyzed bacterial community shifts in the soil surface in day-care centers and commensal bacteria inhabiting the mouth, skin, and gut of children. We compared two different day-care environments: standard urban day-care centers and intervention day-care centers. Yards in the latter were amended with biodiverse forest floor vegetation and sod at the beginning of the study. Results: Intervention caused a long-standing increase in the relative abundance of nonpathogenic environmental mycobacteria in the surface soils. Treatment-specific shifts became evident in the community composition of Gammaproteobacteria, Negativicutes, and Bacilli, which jointly accounted for almost 40 and 50% of the taxa on the intervention day-care children's skin and in saliva, respectively. In the year-one skin swabs, richness of Alpha-, Beta-, and Gammaproteobacteria was higher, and the relative abundance of potentially pathogenic bacteria, including Haemophilus parainfluenzae, Streptococcus sp., and Veillonella sp., was lower among children in intervention day-care centers compared with children in standard day-care centers. In the gut, the relative abundance of Clostridium sensu stricto decreased, particularly among the intervention children. Conclusions: This study shows that a 2-year biodiversity intervention shapes human commensal microbiota, including taxa that have been associated with immune regulation. Results indicate that intervention enriched commensal microbiota and suppressed the potentially pathogenic bacteria on the skin. We recommend future studies that expand intervention strategies to immune response and eventually the incidence of immune-mediated diseases.
U2 - 10.1016/j.envint.2021.106811
DO - 10.1016/j.envint.2021.106811
M3 - Article
AN - SCOPUS:85112533628
SN - 0160-4120
VL - 157
JO - Environment International
JF - Environment International
M1 - 106811
ER -