Environmental toxicants in breast milk of Norwegian mothers and gut bacteria composition and metabolites in their infants at 1 month

From BugSigDB
Needs review
study design
prospective cohort
Citation
PMID
URI
Authors
Iszatt N, Janssen S, Lenters V, Dahl C, Stigum H, Knight R, Mandal S, Peddada S, González A, Midtvedt T, Eggesbø M
Journal
Microbiome
Year
2019
BACKGROUND: Early disruption of the microbial community may influence life-long health. Environmental toxicants can contaminate breast milk and the developing infant gut microbiome is directly exposed. We investigated whether environmental toxicants in breastmilk affect the composition and function of the infant gut microbiome at 1 month. We measured environmental toxicants in breastmilk, fecal short-chain fatty acids (SCFAs), and gut microbial composition from 16S rRNA gene amplicon sequencing using samples from 267 mother-child pairs in the Norwegian Microbiota Cohort (NoMIC). We tested 28 chemical exposures: polychlorinated biphenyls (PCBs), polybrominated flame retardants (PBDEs), per- and polyfluoroalkyl substances (PFASs), and organochlorine pesticides. We assessed chemical exposure and alpha diversity/SCFAs using elastic net regression modeling and generalized linear models, adjusting for confounders, and variation in beta diversity (UniFrac), taxa abundance (ANCOM), and predicted metagenomes (PiCRUSt) in low, medium, and high exposed groups. RESULTS: PBDE-28 and the surfactant perfluorooctanesulfonic acid (PFOS) were associated with less microbiome diversity. Some sub-OTUs of Lactobacillus, an important genus in early life, were lower in abundance in samples from infants with relative "high" (> 80th percentile) vs. "low" (< 20th percentile) toxicant exposure in this cohort. Moreover, breast milk toxicants were associated with microbiome functionality, explaining up to 34% of variance in acetic and propionic SCFAs, essential signaling molecules. Per one standard deviation of exposure, PBDE-28 was associated with less propionic acid (- 24% [95% CI - 35% to - 14%] relative to the mean), and PCB-209 with less acetic acid (- 15% [95% CI - 29% to - 0.4%]). Conversely, PFOA and dioxin-like PCB-167 were associated with 61% (95% CI 35% to 87%) and 22% (95% CI 8% to 35%) more propionic and acetic acid, respectively. CONCLUSIONS: Environmental toxicant exposure may influence infant gut microbial function during a critical developmental window. Future studies are needed to replicate these novel findings and investigate whether this has any impact on child health.

Experiment 1


Needs review

Curated date: 2021/01/10

Curator: WikiWorks743

Revision editor(s): WikiWorks753, WikiWorks743

Subjects

Location of subjects Country from which study subjects were recruited
Norway
Host species Species from which microbiome was sampled (if applicable)
Homo sapiens
Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology
Feces Cow dung,Cow pat,Droppings,Dung,Excrement,Excreta,Faeces,Fecal material,Fecal matter,Fewmet,Frass,Guano,Matières fécales@fr,Merde@fr,Ordure,Partie de la merde@fr,Piece of shit,Porción de mierda@es,Portion of dung,Portion of excrement,Portion of faeces,Portion of fecal material,Portion of fecal matter,Portion of feces,Portion of guano,Portion of scat,Portionem cacas,Scat,Spoor,Spraint,Stool,Teil der fäkalien@de,Feces
Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology
breast milk measurement breast milk measurement
Group 0 name Corresponds to the control (unexposed) group for case-control studies
one-month age infants exposed to low chemical breast milk
Group 1 name Corresponds to the case (exposed) group for case-control studies
one-month age infants exposed to high chemical breast milk
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
low chemical exposure is < 20th percentile breast milk toxicant exposure and high chemical exposure is ≥ 80th percentile breast milk toxicant exposure.
Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any)
more than two weeks prior sampling

Lab analysis

Sequencing type Experimental technique used for quantifying microbial abundance
16S
16S variable region One or more hypervariable region(s) of the bacterial 16S gene
V4
Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance
Illumina

Statistical Analysis

Statistical test Statistical test or computational tool used for differential abundance testing
Mann-Whitney (Wilcoxon)
Significance threshold p-value or FDR threshold used for differential abundance testing (if any)
0.05
MHT correction Have statistical tests be corrected for multiple hypothesis testing (MHT)?
Yes


Confounders controlled for Confounding factors that have been accounted for by stratification or model adjustment
gestational age

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness
increased

Signature 1

Needs review

Curated date: 2020-01-15

Curator: Shaimaa Elsafoury

Revision editor(s): WikiWorks743, Fatima

Source: Figure 2

Description: Differentially abundant sequences in the high vs. low chemical exposure groups.

Abundance in Group 1: increased abundance in one-month age infants exposed to high chemical breast milk

NCBI Links
Clostridium
Enterococcus
Streptococcaceae
Oxychloe

Revision editor(s): WikiWorks743, Fatima

Signature 2

Needs review

Curated date: 2020-01-15

Curator: Shaimaa Elsafoury

Revision editor(s): WikiWorks743

Source: Figure 2

Description: Differentially abundant sequences in the high vs. low chemical exposure groups.

Abundance in Group 1: decreased abundance in one-month age infants exposed to high chemical breast milk

NCBI Links
Lactobacillus
Veillonella

Revision editor(s): WikiWorks743