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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Diet, Genomics and Immunology Laboratory » Research » Publications at this Location » Publication #357130

Research Project: Dietary Regulation of Immunity and Inflammation

Location: Diet, Genomics and Immunology Laboratory

Title: Pomegranate peel extract alters the microbiome in mice and dysbiosis caused by Citrobacter rodentium infection

Author
item George, Nadja
item Cheung, Lumei
item Luthria, Devanand - Dave
item Santin-duran, Monica
item Dawson, Harry
item Bhagwat, Arvind
item Smith, Allen

Submitted to: Journal of Food Science and Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary: We previously showed that treatment with a pomegranate peel extract (PPX) decreased the damage to the colon of mice infected with Citrobacter rodentium (Cr). Resistance to the ill effects of Cr infection can be influenced by the host microbiome and the mouse strain used, C3H/HeNCr, being more susceptible than C57Bl/6 mice. Here we investigate the effects of a pomegranate peel extract (PPX) on the microbiome of uninfected or Cr-infected C3H/HeNCr mice. To determine if PPX treatment altered the host microbiome, mice were orally given PPX for 14 days prior to infection with Cr and for the duration of the experiment. The microbiome was sequenced to determine the bacterial composition of the microbiome in untreated and PPX treated mice before and after infection. The analysis showed distinct groupings for untreated and POM treated mice. In uninfected mice, PPX treatment decreased the ratio of two bacterial strains, Firmicute and Bacteroides with PPX treatment increasing the percentage of Bacteriodetes while decreasing Firmicutes and Lactobacilli yielding a distinct bacterial make-up for PPX-treated mice. Based on the analysis, Cr levels in the mice reached 22% while PPX-treated mice had a relative abundance of 5%, while the absolute amount of live Cr was not different. These results suggest that PPX treatment made the microbiome more resistant to change by the infection with Cr, thus reducing colon damage.

Technical Abstract: We previously showed that treatment with a pomegranate peel extract (PPX) decreased the pathogenicity of Citrobacter rodentium (Cr) infections. Resistance to the pathological effects of Cr infection can be influenced by the host microbiome and the mouse strain used with C3H/HeNCr mice being more susceptible than C57Bl/6 mice. Here we investigate the effects of a pomegranate peel extract (PPX) on the microbiome of uninfected or Cr-infected C3H/HeNCr mice. To determine if PPX treatment altered the host microbiome, mice were orally administered PPX for 14 days prior to infection with Cr and for the duration of the experiment. 16S deep-sequencing was used to determine the bacterial composition of the microbiome in untreated and PPX treated mice before and after infection. Principle component analysis showed distinct grouping for untreated and POM treated mice. In uninfected mice, PPX treatment decreased the Firmicute/Bacteroides ratio with PPX treatment increasing the percentage of Bacteriodetes while decreasing Firmicutes and Lactobacilli yielding a distinct microbiome signature for PPX-treated mice. Based on relative abundance, Cr levels in C3H/HeNCr reached nearly 25% while PPX-treated mice had a relative abundance of 5%, while the absolute numbers of viable Cr was not different. These results suggest that PPX treatment made the microbiome more resistant to displacement by the subsequent infection with Cr, thus reducing the percentage of the total microbiome that Cr and colon pathology.