A few things that benefit gut flora and inhibit pathogens

The essential oils of Caraway (C. carvi), Lavender (L. angustifolia), Ajwain (T.copticum), and Orange (C. aurantium) may have therapeutic value in treating intestinal dysbios.
Abstract Title:

Essential oils in the treatment of intestinal dysbiosis: A preliminary in vitro study.
Abstract Source:

Altern Med Rev. 2009 Dec;14(4):380-4. PMID: 20030464

Article Affiliation:

School of Health and Human Sciences, Southern Cross University. drjah13@yahoo.com
Abstract:

INTRODUCTION: Dysbiosis is associated with a number of gastrointestinal and systemic disorders. There is a need for selectively acting antimicrobial agents capable of inhibiting the growth of potentially pathogenic microorganisms, or those found to be out of balance, while not negatively impacting the bulk gastrointestinal tract microflora. OBJECTIVE: The purpose of this in vitro study is to examine the potential of a selection of essential oils as agents to treat dysbiosis. MATERIALS AND METHODS: Eight essential oils were examined using the agar dilution method, including Carum carvi, Citrus aurantium var. amara, Foeniculum vulgare dulce, Illicium verum, Lavandula angustifolia, Mentha arvensis, Mentha x piperita, and Trachyspermum copticum. Doubling dilutions of the essential oils were tested against 12 species of intestinal bacteria, which represent the major genera found in the human gastrointestinal tract (GIT). RESULTS: Carum carvi, Lavandula angustifolia, Trachyspermum copticum, and Citrus aurantium var. amara essential oils displayed the greatest degree of selectivity, inhibiting the growth of potential pathogens at concentrations that had no effect on the beneficial bacteria examined. CONCLUSION: The most promising essential oils for the treatment of intestinal dysbiosis are Carum carvi, Lavandula angustifolia, Trachyspermum copticum, and Citrus aurantium var. amara. The herbs from which these oils are derived have long been used in the treatment of gastrointestinal symptoms and the in vitro results of this study suggest that their ingestion will have little detrimental impact on beneficial members of the GIT microflora. More research is needed, however, to investigate tolerability and safety concerns, and verify the selective action of these agents.


Tabebuia tree bark contains compounds which inhibit pathogenic bacteria while having no adverse effect on beneficial probiotic strains.
Abstract Title:

Selective growth-inhibiting effects of compounds identified in Tabebuia impetiginosa inner bark on human intestinal bacteria.

Abstract Source:

J Agric Food Chem. 2005 Feb 23;53(4):1152-7. PMID: 15713033

Abstract:

The growth-inhibiting activity of anthraquinone-2-carboxylic acid and lapachol identified in the inner bark of taheebo, Tabebuia impetiginosa, toward 10 human intestinal bacteria was evaluated by using a paper disk diffusion bioassay and compared to those of seven lapachol congeners (1,4-naphthoquinone, naphthazarin, menadione, lawsone, plumbagin, juglone, and dichlone) as well as two commercially available antibiotics, chloramphenicol and tetracycline. Anthraquinone-2-carboxylic acid exhibited very strong growth inhibition of Clostridium paraputrificum at 1 microg/disk while 100 microg/disk of lapachol was needed for moderate growth inhibition of the same organism. These two isolates exhibited weak inhibition of Clostridium perfringens and Escherichia coli at 100 microg/disk while no adverse effects were observed on the growth of Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium infantis, Lactobacillus acidophilus, and Lactobacillus casei at 1000 microg/disk. Structure-activity relationships indicate that a methyl group in the C-2 position of 1,4-naphthoquinone derivatives might play an important role in antibacterial activity.


Cocoa-derived flavanols are effective prebiotics as demonstrated in healthy human volunteers.
Abstract Title:

Prebiotic evaluation of cocoa-derived flavanols in healthy humans by using a randomized, controlled, double-blind, crossover intervention study.
Abstract Source:

Am J Clin Nutr. 2010 Nov 10. Epub 2010 Nov 10. PMID: 21068351

Abstract Author(s):

Ana Rodriguez-Mateos, Catherine Kwik-Uribe, Glenn R Gibson, Jelena Vulevic, Jeremy Pe Spencer, Xenofon Tzounis
Article Affiliation:

Department of Food and Nutritional Sciences, The University of Reading, Reading, United Kingdom, and the Analytical and Applied Sciences Group, Mars Inc, Hackettstown, NJ.
Abstract:

BACKGROUND: The absorption of cocoa flavanols in the small intestine is limited, and the majority of the flavanols reach the large intestine where they may be metabolized by resident microbiota. OBJECTIVE: We assessed the prebiotic potential of cocoa flavanols in a randomized, double-blind, crossover, controlled intervention study. DESIGN: Twenty-two healthy human volunteers were randomly assigned to either a high-cocoa flavanol (HCF) group (494 mg cocoa flavanols/d) or low-cocoa flavanol (LCF) group (23 mg cocoa flavanols/d) for 4 wk. This was followed by a 4-wk washout period before volunteers crossed to the alternant arm. Fecal samples were recovered before and after each intervention, and bacterial numbers were measured by fluorescent in situ hybridization. A number of other biochemical and physiologic markers were measured. RESULTS: Compared with the consumption of the LCF drink, the daily consumption of the HCF drink for 4 wk significantly increased the bifidobacterial (P<0.01) and lactobacilli (P<0.001) populations but significantly decreased clostridia counts (P<0.001). These microbial changes were paralleled by significant reductions in plasma triacylglycerol (P<0.05) and C-reactive protein (P<0.05) concentrations. Furthermore, changes in C-reactive protein concentrations were linked to changes in lactobacilli counts (P<0.05, R(2) = -0.33 for the model). These in vivo changes were closely paralleled by cocoa flavanol-induced bacterial changes in mixed-batch culture experiments. CONCLUSION: This study shows, for the first time to our knowledge, that consumption of cocoa flavanols can significantly affect the growth of select gut microflora in humans, which suggests the potential prebiotic benefits associated with the dietary inclusion of flavanol-rich foods. This trial was registered at clinicaltrials.gov as NCT01091922.


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