Prenatal exposure to trace elements impacts

Overview

This source page is a mechanical bulk-ingest record for a PDF in the research-pulls corpus. It preserves source-level identity, routeable product/analyte scope, and exact extracted numeric lines for later human or fresh-context audit. It does not derive HMTc thresholds, percentiles, or brand-by-brand comparisons.

Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

in maternal hair samples (N = 119) affect diversity and composition of the
reaching homeostasis around 3 years of age6,7. The initial coloniza- The 146 postpartum women enrolled in this study had a mean age of
tion of the gut microbiome is extraordinarily sensitive to external 32.8 ( ± 3.5) years old, with a relatively normal body mass index (mean
stimuli8. Hence, infancy represents a critical window for the colo- 23.1 ± 2.9 kg/m2), more than 12 years of education (97.8%), and an
nization and development of the gut microbiome, and early life average gestational week of 38.8 ( ± 1.1). The mean birth weight of the
modulation of the microbiome may have consequences for health infants (N = 146, the sex ratio about 1:1) was 3257 ( ± 397) g. Approxi-
later in life. mately half of the infants were breast-fed, and 60.2% of the infants
role in microbial colonization. Previous studies have conﬁrmed that (43.3%) and Pseudomonadota (26.5%) were the dominant taxa within
biotics in early life can alter the structure and function of the initial a higher relative abundance of Bacillota (67.5%) and Actinomycetota
neonatal gut microbiome, with profound implications for host (13.6%) (Fig. S1). Furthermore, microbial diversity signiﬁcantly differed
between arsenic and alpha diversity was observed in the whole bacterium (34.2%) and Escherichia-Shigella (9.55%), but compared to
exposed to peripartum antibiotics21. Urinary arsenic in infants was and Collinsella was increased to 13.5% and 4.02%, respectively, while
related to the composition of the gut microbiome at 6 weeks of age. Klebsiella decreased from 9.96% − 0.40% as well as Enterococcus from
Eight genera (six within the phylum Bacillota) were enriched under 5.56% to 0.68%. Metagenomic data from maternal and infant stool
gut microbiome. exposure to trace elements in infants (Table 1). Compared to >90% of
arsenic, and nickel was slightly low at 67%, 78%, and 82%. The med- manganese.
2.59 μg/g, respectively. Except for mercury and selenium, there were deviation increase in selenium concentration, 95% CI (0.002, 0.032),
microbiome at different postpartum visits. Phyla with lower abundance are (First, n = 13; Second, n = 6; Third, n = 13) at different postpartum visits. The vertical
stool samples, stratiﬁed by the visit time into six categories: Infant_First (n = 91), and (E), the box ranges from the 25th to the 75th percentile, and the median value
Infant_Second (n = 58), Infant_Third (n = 29), Mother_First (n = 89), Mother_Second (middle line), while the whiskers extend from each quartile to the minimum and
(n = 56), and Mother_Third (n = 30). C Principal coordinate analysis of paired maximum values within 1.5 × interquartile range (IQR) of the box. Data points
per standard deviation increase in copper concentration, 95% CI Metabolic and functional proﬁles of the gut microbiome
iron concentration, 95% CI (2.05, 4.75), p = 4.18e-05) and Phylogenetic variability in metabolic proﬁles of the infant gut microbiome at dif-
centration, 95% CI (0.283, 0.622), p = 1.73e-05). Prenatal exposure to upregulated and 2 down-regulated) changed signiﬁcantly between 3
deviation increase in manganese concentration, 95% CI (12.3, 84.4), and 49 down-regulated) between 6 and 12 months of age. Linking
increase in manganese concentration, 95% CI (1.14, 10.6), p = 0.024), calculating the Spearman correlation coefﬁcient (Fig. 5C, D). Clear
increase in mercury concentration, 95% CI (-2.50, −0.120), p = 0.048) in between the second and third postpartum visit. These products of
centration, 95% CI (1.02, 5.07), p = 0.014) in forceps delivery infants. partum visit) was associated positively with Streptococcus, and
abundance > 0.5%). As shown in Fig. 4, prenatal exposure to high level while both taxonomic composition and metabolic capacity in infants
stratiﬁed infants. The box ranges from the 25th to the 75th percentile, and the ASVs. Statistical test was permutational multivariate analysis of variance with FDR
minimum and maximum values within 1.5 × interquartile range (IQR) of the box. n = 56, 36, 21; Cesarean delivery, n = 18, 12, 5; Forceps delivery, n = 17, 10, 3; Breast-
Data points beyond this range are considered outliers (single points). Statistical test fed, n = 31, 17, 6; Mix-fed, n = 43, 30, 15; Male, n = 44, 28, 15; Female, n = 47, 30, 14 of
Table 1 | Concentrations of trace elements in the maternal hairs (N = 119, μg/g)
Class Elements DF Mean (± SD) Min P25 P50 P75 Max
DF detection frequency (%), SD standard deviation, Min, the minimum value; P25, percentile 25; P50, percentile 50; P75, percentile 75; Max, the maximum value; n.d., not detected.
percentile, and the median value (middle line), while the whiskers extend from each 10; Medium copper, n = 41, 26, 13; Low copper, n = 17, 9, 3 of three visits, respec-
quartile to the minimum and maximum values within 1.5 × interquartile range (IQR) tively. Source data are provided as a Source Data ﬁle.
Manganese (High, n = 21; Low, n = 22) Mercury (High, n = 20; Low, n = 20) High exposure (> P25)
Aluminum (High, n = 21; Low, n = 21) Barium (High, n = 22; Low, n = 23)
Copper (High, n = 23; Low, n = 17) Nickel (High, n = 22; Low, n = 19)
We discovered that 27.8% (73 types) of all ARGs were known as MDR We recruited 146 mother-infant pairs and collected hair samples from
ARGs of paired mother-infant at 3 months postpartum (N = 8 pairs). microbiome between low (<P25, percentile 25 of element concentra-

Methods (brief)

samples at 3, 6, and 12 months after delivery for amplicon sequencing
in maternal hair samples (N = 119) affect diversity and composition of the
The initial colonization of the gut microbiome is inﬂuenced by were born via vaginal delivery. We collected hair samples from 119
several intrinsic and extrinsic factors, such as delivery mode and mothers in the postnatal 6 weeks outpatient service, and stool samples
nate ﬁrst encounters an immense quantity and diversity of maternal samples and stool samples are matched in the 83 mother-infant pairs.
neonates16. A key factor shaping the neonatal microbiome devel- sequences of 353 stool samples were acquired by 16S rRNA sequencing
high arsenic exposure, and ﬁfteen genera including Bacteroides and samples also conﬁrmed the trend of development in infant gut
materials, hair samples are collected non-invasively and provide an delivery, vaginal delivery, and cesarean delivery, and between infants
associations with prenatal exposure to trace elements and maternal Hair samples provided by 119 mothers were used to assess prenatal
stool samples, stratiﬁed by the visit time into six categories: Infant_First (n = 91), and (E), the box ranges from the 25th to the 75th percentile, and the median value
mother-infant samples based on the unweighted UniFrac distance of ASVs. The box beyond this range are considered outliers (single points). For (B) and (E), statistical
plots below showed paired mother-infant samples projected on the ﬁrst principal test was Kruskal–Wallis test with FDR correction for multiple test comparisons, p’
(−0.055, −0.008), p = 0.020). Associations between most trace ele- A total of 3867 metabolites were identiﬁed in 198 stool samples. At
delivery mode, feeding patterns, and infant sex. For example, in mix- be readily differentiated in infant samples, not in maternal samples
We discovered that 27.8% (73 types) of all ARGs were known as MDR We recruited 146 mother-infant pairs and collected hair samples from
Fig. 6 | Expansion and diversiﬁcation of microbial community structure and maternal and infant stool samples. The box ranges from the 25th to the 75th
postpartum visits. The relative abundance of pathways in the given sample was (IQR) of the box. Data points beyond this range are considered outliers (single
Fig. 7 | Characterization of ARG proﬁles in the stool samples of paired mother- analysis based on Bray-Curtis distance of ARGs relative abundances in the maternal

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

Verification notes

Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised