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

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.

Therapeutic Uses of Triphala in Ayurvedic Medicine.

AIM: The aim of this article is to review the current literature on the therapeutic uses and efficacy of Triphala. Herbal remedies are among the most ancient medicines used in traditional systems of healthcare such as Ayurveda. Triphala, a well-recognized and highly efficacious polyherbal Ayurvedic medicine consisting of fruits of the plant species Emblica officinalis (Amalaki), Terminalia bellerica (Bibhitaki), and Terminalia chebula (Haritaki), is a cornerstone of gastrointestinal and rejuvenative treatment. METHODS: A search of the PubMed database was conducted. RESULTS: In addition, numerous additional therapeutic uses described both in the Ayurvedic medical literature and anecdotally are being validated scientifically. In addition to laxative action, Triphala research has found the formula to be potentially effective for several clinical uses such as appetite stimulation, reduction of hyperacidity, antioxidant, anti-inflammatory, immunomodulating, antibacterial, antimutagenic, adaptogenic, hypoglycemic, antineoplastic, chemoprotective, and radioprotective effects, and prevention of dental caries. Polyphenols in Triphala modulate the human gut microbiome and thereby promote the growth of beneficial Bifidobacteria and Lactobacillus while inhibiting the growth of undesirable gut microbes. The bioactivity of Triphala is elicited by gut microbiota to generate a variety of anti-inflammatory compounds. CONCLUSIONS: This review summarizes recent data on pharmacological properties and clinical effects of Triphala while highlighting areas in need of additional investigation and clinical development.