Chromium and ABX resistant pseudomonas...

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The study was on rats, and used a form of chromium I hadn't heard of, but

still...interesting.

Effects of Chromium on the Resident Gut Bacteria of Rat

Authors: Shrivastava, Richa1; Kannan, A.1; Upreti, R.1; Chaturvedi, U.1

Source: Toxicology Mechanisms and Methods, Volume 15, Number 3, May-June 2005 ,

pp.

211-218(8)

Publisher: and Francis Ltd

Abstract:

The major nonoccupational source of chromium (Cr) for humans is through

ingestion with

food and water, but its effect on the gut microflora has not been studied. The

present

study was, therefore, undertaken to investigate the effects of chronic ingestion

of

potassium dichromate (chromium VI) on the resident gut bacteria of male Wistar

rats. A

group of rats was kept on drinking water containing 10 ppm chromium VI (Cr [VI])

(called

Cr-stressed animals) and the other group was given plain water.

After 10 weeks, Lactobacillus, Pseudomonas sp., and Escherichia coli were

isolated from

the cecum of the rats and various studies were performed. The most significant

findings of

the present study were the stimulation of growth of facultative gut bacteria

from the Cr-

stressed rats and the significant increase of growth even in the presence of

lower

concentrations of Cr.

Furthermore, the capacity to reduce Cr (VI) was significantly decreased along

with the

increased tolerance of the bacteria to Cr (higher minimum inhibitory

concentration [MIC]

values), which was associated with the development of antibiotic resistance.

The effects were most marked with the Pseudomonas sp. and least with the E.

coli. The

antibiotic resistance developed with the Lactobacillus may be a blessing in

disguise,

because the bacteria may continue to provide benefits even in patients given

antibiotic

therapy. The gut bacteria thus provide the first line of defense to the body by

converting

toxic Cr (VI) to a less toxic Cr (III) and may act as a prebiotic.

Keywords: Gut Microflora; Intestinal Bacteria; Lactobacillus; Pseudomonas;

Escherichia coli;

Chromium Resistance; Chromium (VI) Reduction