Oral lead exposure induces dysbacteriosis in rats.
OBJECTIVE
Lead's (Pb(II)) possible role in intestinal pathologies of microbial etiology remains mostly unknown. The aim of this study was to examine the effects of lead on the gut microbial community and its interactions with rat intestinal epithelium.


METHODS
The lead-induced changes in different intestinal microbial groups (lactose-positive lac(+) and -negative lac(-) E.coli strains, lactobacilli and yeasts) were followed separately by the colony-forming unit (CFU) method. Samples were taken from outbred white rats subjected to different exposure schedules. Additionally, the impact of different lead doses on microbial adhesion to cultured intestinal cells (IEC-6) was investigated. Finally, the lead accumulation and distribution were measured by means of atomic absorption spectrometry.


RESULTS
For the first time it was shown that oral lead exposure causes drastic changes in the gut microbial community. Proportional to the lead dose received, the relative number of lactose-negative E.coli cells increased dramatically (up to 1,000-fold) in comparison to the other microbial groups during 2 wk of exposure. Considering the number of microbes in the intestine, such a shift in intestinal microflora (dysbacteriosis) is very significant. Adhesion studies showed certain stimulating effects of lead on E. coli attachment to rat intestinal epithelium as compared to Lactobacillus attachment.


CONCLUSIONS
The mechanisms providing the apparent competitive success of the lac(-) group are unclear but could be related to changes in surface interactions between microbial and host cells. This study may provide important clues for understanding the pathological effects of metal dietary toxins in human beings.
Sadykov
Rustam
R
Kazakh National University Named after Al-Farabi, Republic of Kazakhstan.
Digel
Ilya
I
Artmann
Aysegül Temiz
AT
Porst
Dariusz
D
Linder
Peter
P
Kayser
Peter
P
Artmann
Gerhard
G
Savitskaya
Irina
I
Zhubanova
Azhar
A
D000284:Administration, Oral; D000818:Animals; D015169:Colony Count, Microbial; D046508:Culture Techniques; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development*; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000382:microbiology*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000382:microbiology*; D007422:Intestines / Q000382:microbiology*; D007778:Lactobacillus / Q000187:drug effects / Q000254:growth & development*; D007854:Lead / Q000494:pharmacology / Q000633:toxicity*; D007855:Lead Poisoning / Q000382:microbiology*; D009942:Organometallic Compounds / Q000494:pharmacology; D051381:Rats; D012996:Solutions / Q000737:chemistry / Q000633:toxicity; D013054:Spectrophotometry, Atomic; D015003:Yeasts / Q000187:drug effects / Q000254:growth & development*
D009942:Organometallic Compounds; D012996:Solutions; D007854:Lead; C029891:lead chloride; C008261:lead acetate