Prebiotic Potential of Herbal Medicines Used in Digestive Health and Disease.

Journal of alternative and complementary medicine (New York, N.Y.). 2018;24(7):656-665

Plain language summary

Triphala, licorice and slippery elm are key treatments for gastrointestinal health and disease in traditional systems of medicine. Prebiotics are defined as undigested dietary carbohydrates that alter the gut microbiota and promote human health. They reach the site of action in the colon mostly unmetabolized and are broken down by enzymes. The aim of the study was to find out whether the complex carbohydrates present in herbal medicine may be strong drivers to modulate gut microbiota composition. The study recruited 12 healthy men and women, aged between 30-60 years who had previously followed a vegan or vegetarian diet for more than 1 year, to donate a single stool sample. Results show that both the sugar and protein content of these herbal medicines drive alterations in gut microbiota profiles. Each of these herbal medicines studied, uniquely altered gut bacteria communities. Authors conclude that the health benefits of these herbs are mostly due to their ability to alter the gut microbiota in a manner that is predicted to improve colonic epithelium function, reduce inflammation, and promote protection from bacterial pathogenic infection.

Abstract

INTRODUCTION The prebiotic potential of herbal medicines has been scarcely studied. METHODS The authors therefore used anaerobic human fecal cultivation to investigate whether three herbal medicines commonly used in gastrointestinal health and disease in Ayurveda alter the growth and abundance of specific bacterial species. RESULTS Profiling of cultures supplemented with Glycyrrhiza glabra, Ulmus rubra, or triphala formulation by 16S rDNA sequencing revealed profound changes in diverse taxa in human gut microbiota. Principal coordinate analysis highlights that each herbal medicine drives the formation of unique microbial communities. The relative abundance of approximately one-third of the 299 species profiled was altered by all 3 medicines, whereas additional species displayed herb-specific alterations. Herb supplementation increased the abundance of many bacteria known to promote human health, including Bifidobacterium spp., Lactobacillus spp., and Bacteroides spp. Herb supplementation resulted in the reduced relative abundance of many species, including potential pathogens such as Citrobacter freundii and Klebsiella pneumoniae. Herbal medicines induced blooms of butyrate- and propionate-producing species. U. rubra and triphala significantly increased the relative abundance of butyrate-producing bacteria, whereas G. glabra induced the largest increase in propionate-producing species. To achieve greater insight into the mechanisms through which herbal medicines alter microbial communities, the authors assessed the shifts in abundance of glycosyl hydrolase families induced by each herbal medicine. Herb supplementation, particularly G. glabra, significantly increased the representation and potential expression of several glycosyl hydrolase families. DISCUSSION These studies are novel in highlighting the significant prebiotic potential of medicinal herbs and suggest that the health benefits of these herbs are due, at least in part, to their ability to modulate the gut microbiota in a manner predicted to improve colonic epithelium function, reduce inflammation, and protect from opportunistic infection. Forthcoming studies in human clinical trials will test the concordance of the results generated in vitro and the predictions made by genome analyses.

Lifestyle medicine

Fundamental Clinical Imbalances : Detoxification and biotransformational
Patient Centred Factors : Triggers/Prebiotic
Environmental Inputs : Nutrients
Personal Lifestyle Factors : Nutrition
Functional Laboratory Testing : Stool
Bioactive Substances : Butyrate ; Propionate

Methodological quality

Allocation concealment : Not applicable
Publication Type : Journal Article

Metadata