The global rise in obesity rates has prompted a thorough evaluation of dietary strategies that may alleviate this metabolic issue. Fermented tea, a beverage rich in polyphenols and catechins, has emerged as a viable therapeutic option for obesity management. This review discusses the role of fermented tea in modulating the gut microbiome, a critical factor in energy regulation and obesity. We explore how the bioactive components in fermented tea influence gut health and their implications for metabolic health. Fermented tea may inhibit weight gain and fat accumulation in obese animal models, likely by promoting beneficial bacteria and suppressing harmful species. Changes in the production of short-chain fatty acids and improvements in gut barrier integrity are linked to enhanced insulin sensitivity and reduced inflammatory markers, essential for effective obesity management. However, barriers remain in applying these findings in clinical settings, such as the need for standardized fermentation techniques and accurate dosage assessments. This review underscores the therapeutic potential of fermented tea in obesity treatment and advocates for further research to enhance its integration with public health initiatives.

Hypertension is a major global health challenge, with excessive dietary salt intake recognized as a key environmental factor contributing to its pathogenesis. However, safe and effective dietary interventions for salt-sensitive hypertension remain limited. Vine tea (Ampelopsis grossedentata), a traditional herbal tea widely consumed for centuries in southern China, has been reported to exhibit antioxidant, anti-inflammatory, and hepatoprotective activities, yet its antihypertensive efficacy and underlying mechanisms remain unclear. In this study, the chemical profile of vine tea aqueous extract (VTE) was characterized by UPLC–Q–TOF–MS, identifying dihydromyricetin, isoquercitrin, and myricetin as the predominant flavonoids. The protective effects of VTE were evaluated in C57BL/6J mice with high-salt-diet (HSD)-induced hypertension. VTE treatment significantly lowered systolic blood pressure and ameliorated cardiac and renal injury, accompanied by reduced inflammation, fibrosis, and cardiac stress-related gene expression. Gut microbiota analysis using 16S rRNA gene sequencing revealed that VTE restored microbial richness and diversity, enriching short-chain fatty acid-producing taxa while suppressing pathogenic Desulfovibrio and Ruminococcus torques. Untargeted plasma metabolomic profiling based on UPLC–Q–TOF–MS further showed that VTE normalized tryptophan, bile acid, and glycerophospholipid metabolism, decreasing the uremic toxin indoxyl sulfate while increasing tauroursodeoxycholic acid. Notably, these protective effects were abolished under antibiotic-induced microbiota depletion, confirming that VTE acts through a gut microbiota-dependent mechanism. Collectively, VTE mitigates salt-induced hypertension and cardiorenal injury by remodeling the gut microbiota–metabolite axis, supporting its potential as a natural dietary intervention for managing hypertension.