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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Dairy and Functional Foods Research » People & Locations » Karley Mahalak
Karley K Mahalak
Dairy and Functional Foods Research
Research Molecular Biologist

Phone: (215) 836-6922
Fax:

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Projects
In vitro Human Gut System: Interactions Between Diet, Food Processing, and Microbiota
In-House Appropriated (D)
  Accession Number: 439225
Fatty Acids Metabolism in the Gastrointestinal Tract Using In Vitro Enteroid Models Derived from Mice and Humans
Non-Assistance Cooperative Agreement (S)
  Accession Number: 437564

Publications (Clicking on the reprint icon Reprint Icon will take you to the publication reprint.)
Supplementation with soluble or insoluble rice-bran fibers increases short-chain fatty acid producing bacteria in the gut microbiota in vitro Reprint Icon - (Peer Reviewed Journal)
Mahalak, K.K., Liu, L.S., Bobokalonov, J., Narrowe, A.B., Firrman, J., Bittinger, K., Hu, W., Jones, S.M., Mustafa, A.M. 2024. Supplementation with soluble or insoluble rice-bran fibers increases short-chain fatty acid producing bacteria in the gut microbiota in vitro. Frontiers in Nutrition. https://doi.org/10.3389/fnut.2024.1304045.
Preservation of conjugated primary bile acids by oxygenation of the small intestinal microbiota in vitro Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Friedman, E.S., Hecht, A., Strange, W.C., Narrowe, A.B., Mahalak, K.K., Wu, G.D., Liu, L.S. 2024. Preservation of conjugated primary bile acids by oxygenation of the small intestinal microbiota in vitro. mBio. 15(6). https://doi.org/10.1128/mbio.00943-24.
Targeted remodeling of the human gut microbiome using Juemingzi (Senna seed extracts) Reprint Icon - (Peer Reviewed Journal)
Narrowe, A.B., Scarino Lemons, J.M., Mahalak, K.K., Firrman, J., Van Den Abbeele, P., Baudot, A., Deyaert, S., Li, Y., Yu, L., Liu, L.S. 2024. Targeted remodeling of the human gut microbiome using Juemingzi (Senna seed extracts). Frontiers in Cellular and Infection Microbiology. 14. https://doi.org/10.3389/fcimb.2024.1296619.
Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Narrowe, A.B., Liu, L.S., Mahalak, K.K., Scarino Lemons, J.M., Van Den Abbeele, P., Baudot, A., Deyaert, S., Li, Y., Yao, Y., Yu, L. 2024. Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste. PLOS ONE. 19(4):e0301381. https://doi.org/10.1371/journal.pone.0301381.
Metagenomes and metagenome-assembled genomes from ex vivo fecal incubations of six unique donors Reprint Icon - (Peer Reviewed Journal)
Narrowe, A.B., Liu, L.S., Scarino Lemons, J.M., Firrman, J., Mahalak, K.K., Deyaert, S., Baudot, A., Van Den Abbeele, P. 2024. Metagenomes and metagenome-assembled genomes from ex vivo fecal incubations of six unique donors. Microbiology Resource Announcements. https://doi.org/10.1128/mra.00862-23.
Impact of Baizhu, Daqingye, and Hehuan extracts on the human gut microbiome Reprint Icon - (Peer Reviewed Journal)
Scarino Lemons, J.M., Narrowe, A.B., Liu, L.S., Firrman, J., Mahalak, K.K., Van Den Abbeele, P., Baudot, A., Deyaert, S., Li, Y., Yu, L. 2023. Impact of Baizhu, Daqingye, and Hehuan extracts on the human gut microbiome. Frontiers in Cellular and Infection Microbiology. 13:1298392. https://doi.org/10.3389/fcimb.2023.1298392.
Impact of ivermectin on gut microbial ecosystem Reprint Icon - (Peer Reviewed Journal)
Liu, L.S., Mahalak, K.K., Bobokalonov, J.D., Narrowe, A.B., Firrman, J., Scarino Lemons, J.M., Bittinger, K., Hu, W., Jones, S.M., Mustafa, A.M. 2023. Impact of ivermectin on gut microbial ecosystem. International Journal of Molecular Sciences. 24:16125. https://doi.org/10.3390/ijms242216125.
Transcriptomic analysis on the regulation of tomato ripening by carbon dioxide Reprint Icon - (Peer Reviewed Journal)
Bobokalonov, J., Liu, Y., Mahalak, K.K., Firrman, J., Sheen, S., Zhou, S., Liu, L.S. 2023. Transcriptomic analysis on the regulation of tomato ripening by carbon dioxide. Sci. 5(3):26. https://doi.org/10.3390/sci5030026.
Lacticaseibacillus rhamnosus strain GG (LGG) regulate gut microbial metabolites, an in vitro study using three mature human gut microbial cultures in a simulator of human intestinal microbial ecosystem (SHIME) Reprint Icon - (Peer Reviewed Journal)
Liu, L.S., Narrowe, A.B., Firrman, J., Mahalak, K.K., Bobokalonov, J., Scarino Lemons, J.M., Bittinger, K., Daniel, S., Tanes, C., Mattei, L., Friendman, E., Soares, J.W., Masuko, K., Zeng, W., Tomasula, M.M. 2023. Lacticaseibacillus rhamnosus strain GG (LGG) regulate gut microbial metabolites, an in vitro study using three mature human gut microbial cultures in a simulator of human intestinal microbial ecosystem (SHIME). Foods. https://doi.org/10.3390/foods12112105.
An in-vitro analysis of how lactose modifies the gut microbiota structure and function of adults in a donor-independent manner Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Liu, L.S., Mahalak, K.K., Hu, W., Bittinger, K., Moustafa, A., Jones, S.M., Narrowe, A.B., Tomasula, M.M. 2023. An in-vitro analysis of how lactose modifies the gut microbiota structure and function of adults in a donor-independent manner. Frontiers in Nutrition. https://doi.org/10.3389/fnut.2022.1040744.
Fructooligosaccharides (FOS) differentially modifies the in vitro gut microbiota in an age-dependent manner. Reprint Icon - (Peer Reviewed Journal)
Mahalak, K.K., Firrman, J., Narrowe, A.B., Hu, W., Bittinger, K., Moustafa, A., Liu, L.S. 2023. Fructooligosaccharides (FOS) differentially modifies the in vitro gut microbiota in an age-dependent manner. Frontiers in Nutrition. https://doi.org/10.3389/fnut.2022.1058910.
Modulation of the Gut Microbiota Structure and Function by Two Structurally Different Lemon Pectins Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Mahalak, K.K., Bobokalonov, J., Liu, L.S., Lee, J., Bittinger, K., Mattei, L., Gadaingan, R.T., Narrowe, A.B., Scarino Lemons, J.M. 2022. Modulation of the Gut Microbiota Structure and Function by Two Structurally Different Lemon Pectins. Foods. https://doi.org/10.3390/foods11233877.
Persistence of the probiotic Lacticaseibacillus rhamnosus strain GG (LGG) in an in vitro model of the gut microbiome Reprint Icon - (Peer Reviewed Journal)
Mahalak, K.K., Firrman, J., Bobokalonov, J., Narrowe, A.B., Bittinger, K., Daniel, S., Tanes, C., Mattei, L., Zeng, W., Soares, J.W., Kobori, M., Scarino Lemons, J.M., Tomasula, M.M., Liu, L.S. 2022. Persistence of the probiotic Lacticaseibacillus rhamnosus strain GG (LGG) in an in vitro model of the gut microbiome. International Journal of Molecular Sciences. https://doi.org/10.3390/ijms232112973.
The impact of environmental pH on the gut microbiota community structure and short chain fatty acid production Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Liu, L.S., Mahalak, K.K., Tu, V., Tanes, C., Bittinger, K., Bobokalonov, J., Mattei, L., Zhang, H., Van Den Abeele, P. 2022. The impact of environmental pH on the gut microbiota community structure and short chain fatty acid production. FEMS Microbiology Ecology. 98(5). https://doi.org/10.1093/femsec/fiac038.
Analysis of the ability of capsaicin to modulate the human gut microbiota in vitro Reprint Icon - (Peer Reviewed Journal)
Mahalak, K.K., Bobokalonov, J., Firrman, J., Williams, R., Evans, B., Fanelli, B., Soares, J., Liu, L.S., Kobori, M. 2022. Analysis of the ability of capsaicin to modulate the human gut microbiota in vitro. Nutrients. https://doi.org/10.3390/nu14061283.
Changes to environmental pH alters the colon microbial community in terms of both structure and function: An in vitro analysis - (Abstract Only)
Environmental pH is a determinant of the gut microbiota community composition and production of short chain fatty acids - (Abstract Only)
Comparative analysis of the gut microbiota cultured in vitro using a single colon versus a 3-stage colon experimental design Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Liu, L.S., Mahalak, K.K., Tanes, C., Bittinger, K., Bobokalonov, J., Van Den Abbeele, P., Mattei, L., Zhang, H. 2021. Comparative analysis of the gut microbiota cultured in vitro using a single colon versus a 3-stage colon experimental design. Applied Microbiology and Biotechnology. volume 105, pages 3353–3367. https://link.springer.com/article/10.1007/s00253-021-11241-x.
Triclosan has a robust, yet reversible impact on human gut microbial composition in vitro. Reprint Icon - (Peer Reviewed Journal)
Mahalak, K.K., Firrman, J., Lee, J., Bittinger, K., Nunez, A., Bobokalonov, J., Arango-Argoty, G., Zhang, L., Zhang, G., Liu, L.S. 2020. Triclosan has a robust, yet reversible impact on human gut microbial composition in vitro. PLoS One. 15(6): 1-22. https://doi.org/10.1371/journal.pone.0234046.
Impact of steviol glycosides and erythritol on the human and Cebus apella gut microbiome Reprint Icon - (Peer Reviewed Journal)
Mahalak, K.K., Firrman, J., Tomasula, M.M., Nunez, A., Lee, J., Bittinger, K., Rinaldi, W., Liu, L.S. 2019. Impact of steviol glycosides and erythritol on the human and Cebus apella gut microbiome. Journal of Agricultural and Food Chemistry. Pages A-I. https://doi.org/10.1021/acs.jafc.9b06181.
Metagenomic assessment of the Cebus Apella gut microbiota Reprint Icon - (Peer Reviewed Journal)
Firrman, J., Tanes, C., Bittinger, K., Mahalak, K.K., Rinaldi, W., Liu, L.S. 2019. Metagenomic assessment of the Cebus Apella gut microbiota. American Journal of Primatology. https://doi.org/10.1002/ajp.23023.