Phytochemical Profile, Antibacterial Activity and Effect of Infusions from Polyherbal Tea on Gut Microbiota of Albino Rats

Herbal teas unique taste, aroma and health benefits have led to its increased interest worldwide. Some of the health benefits are attributed to the interaction between the tea's bioactive compounds and the gut microbiota. This study investigated the phytochemical composition, antibacterial activities, and gut microbiota-modulating effects of a polyherbal tea infusion using an albino rat model. Thirty rats were divided into ten groups receiving different formulations (F1–F6), sweetened variants (with sugar or honey), a commercial tea and water as control over 21 days. The gastrointestinal contents were analyzed using the spread plate method; reverse-phase high-performance liquid chromatography (RP-HPLC) method was used for phytochemical analysis, while antibacterial activities were assessed against Escherichia coli and Staphylococcus aureus using the disk diffusion method. Quercetin was the most abundant polyphenol (3.82 mg/L), followed by kaempferol (1.53 mg/L). Formulation 5 consistently showed higher concentrations of gallic acid, chlorogenic acid, Quercetin, kaempferol and apigenin. All polyherbal formulations showed antibacterial activity and E. coli were more susceptible than S. aureus. The tea significantly increased mesophilic aerobic bacterial counts in the duodenum compared to the water control group, suggesting prebiotic-like stimulation of beneficial microbiota. Escherichia coli was detected only in the water control group of the caecum, while Salmonella was absent across all groups. These findings indicate that polyherbal tea can modulate gut microbiota composition, potentially suppress pathogenic organisms and promote beneficial microbial growth, which supports its role as a functional beverage for improving gastrointestinal health.