Evaluating birch leaf tea as a functional herbal beverage: Beneficial impact on the urinary tract, and metabolism in human organism

• Published in: Food research international 2024-08, Vol.189, p.114481, Article 114481
• Main Authors: Popowski, Dominik, Kruk, Aleksandra, Pawłowska, Karolina A., Dolzkho, Diana, Korczak, Maciej, Piwowarski, Jakub P., Roszko, Marek, Granica, Sebastian
• Format: Article
• Language: English
• Subjects: Animals; Anti-Inflammatory Agents - pharmacology; Antiadhesive activity; Betula - chemistry; Biological Availability; Birch leaf; Caco-2; Functional beverages; Functional Food; Gastrointestinal Microbiome - drug effects; Gastrointestinal Microbiome - physiology; Humans; Male; Metabolomics; Metabolomics - methods; Plant Extracts - pharmacology; Plant Leaves - chemistry; Teas, Herbal; Urinary Tract - metabolism; Urinary Tract - microbiology
• ISSN: 0963-9969; 1873-7145; 1873-7145
• DOI: 10.1016/j.foodres.2024.114481

[Display omitted] •Several birch leaf tea constituents (phenolic acids’ and flavonoids’ derivatives) are bioavailable and detected in human urine.•Birch leaf extract possesses anti-inflammatory and antiadhesive activity against uropathogens.•Several phase II metabolites derived from the birch leaf constituents and the products of the biotransformation by gut microbiota are present in urine after birch leaf tea consumption.•Pro-urinary health functional beverages can be based on birch leaf tea. Herbal teas are considered as a potential constituent of novel functional beverages consumed daily. One of the commonly used herbal teas is silver birch (Betula pendula Roth) leaf infusion, traditionally used in urinary tract diseases. In this study, the potential of birch leaf infusion as a functional beverage, emphasizing its active ingredients’ bioavailability, anti-inflammatory, and antiadhesive properties concerning urinary tract health, was investigated. A complex approach was proposed, which included phytochemical screening, bioavailability, gut microbiota biotransformation, and an in vivo test for urine metabolomics assessment. The bioassays confirmed significant anti-inflammatory (interleukins IL-6 and IL-8 secretion) and anti-adhesive (Uropathogenic Escherichia coli and T24 bladder cells) activities. The high-resolution mass spectrometry metabolomics studies linked gut microbiota metabolites and the metabolites present in the urine. Several metabolites connected with phenolics’ consumption were detected in the urine, e.g., glucuronides and sulfates of caffeic acid and dihydroxyphenyl-γ-valerolactones. Based on the presented results, the birch leaf should be considered useful in designing functional beverages, especially targeted to the groups at high risk of urinary diseases.