L-Theanine

• CAS: 3081-61-6
• Catalog Number: ALC-FP-3081616
• Category: Featured Products
• Molecular Weight: 174.2
• Molecular Formula: C7H14N2O3
• Melting Point: 216-218 ºC
• Appearance: White solid
• Sample Lot No.: A24M0402x2797

Case Study

L-Theanine for the Prevention of Ulcerative Colitis via Gut Microbiota Modulation

Xu W, et al. The Journal of Nutritional Biochemistry, 2025, 139, 109845.

L-theanine was investigated for its preventive effect on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) through modulation of gut microbiota and immune responses. Experimental methods included oral administration of L-theanine followed by fecal microbiota transplantation to recipient mice. Colonic structure and histology were assessed alongside cytokine profiling (IL-10, IL-1β). 16S rDNA sequencing and metabolomics identified SCFA-, bile acid-, and tryptophan-related microbiota, including Muribaculaceae, Lachnospiraceae, and Alloprevotella, as key mediators. Flow cytometry revealed reduced Th1/Th17 responses and enhanced Th2/Treg responses, indicating L-theanine's regulation of CD4+ T cell immunity via antigen-presenting dendritic cells and macrophages. This study experimentally demonstrates L-theanine's application in modulating gut microbiota to prevent UC.

L-Theanine for the Amelioration of Late-Life Depression via Multimodal Neurorestoration

Hussain HK, et al. Experimental Gerontology, 2025, 210, 112881.

In a murine model of unpredictable chronic mild stress (UCMS), L-Theanine (2 mg/kg) was administered alone and in combination with Vitamin D (500 IU/kg) to evaluate its neuroprotective and antidepressant effects. Behavioral assays-including the Open Field Test, Elevated Plus Maze, Tail Suspension Test, Forced Swim Test, Hole Board Test, and Sucrose Preference Test-quantified anxiogenic and anhedonic phenotypes. Electrophysiological recordings assessed alpha oscillation restoration (8-13 Hz), while amperometric analysis of brain homogenates measured dopaminergic recovery. Oxidative stress markers (MDA, SOD, catalase) were also evaluated. Co-treatment with L-Theanine and Vitamin D robustly restored thalamocortical coherence, dopaminergic tone, and antioxidant defenses, demonstrating a multimodal experimental approach for addressing late-life depression.

L-Theanine for the Reduction of Muscle Drip Loss via Oxidative Stress Modulation

Huang Y, et al. Food Bioscience, 2025, 72, 107424.

This study evaluated the experimental application of L-theanine in mitigating muscle drip loss under oxidative stress conditions. Mice were exposed to diquat to induce oxidative damage, followed by dietary L-theanine supplementation. Muscle samples were analyzed for reactive oxygen species (ROS), malondialdehyde (MDA), corticosterone (CORT), and antioxidant enzyme activities. Glycolytic enzyme activities, cytoskeletal protein expression (desmin, calpains, integrin β1), and HIF-1α/GRα signaling were assessed using molecular and biochemical assays. L-theanine effectively restored antioxidant capacity, normalized glycolytic flux, and regulated cytoskeletal protein turnover, demonstrating its potential to alleviate oxidative stress-mediated muscle quality deterioration in vivo.

L-Theanine for the Restoration of Intestinal Barrier Function in Ulcerative Colitis

Liu A, et al. Food and Chemical Toxicology, 2025, 202, 115497.

L-Theanine was evaluated for its therapeutic effects on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. Experimental protocols included oral administration of L-theanine, fecal microbiota transplantation, and assessment of gut barrier integrity via histological analysis and tight junction protein expression. Gut microbiota composition was analyzed using 16S rRNA sequencing, while short-chain fatty acid (SCFA) levels were quantified by gas chromatography. L-Theanine treatment enhanced SCFA production, modulated pro- and anti-apoptotic factors, and activated the GPR43/PI3K/AKT signaling pathway, resulting in significant intestinal barrier repair and attenuation of inflammatory responses.

L-Theanine for Enhancing Antioxidant Capacity, Immunity, and Gut Microbiota in Eriocheir sinensis

Yang M, et al. Aquaculture Reports, 2025, 45, 103143

In a controlled aquaculture study, Chinese mitten crabs (Eriocheir sinensis) were administered dietary L-theanine (1.5%) over four- (L4) and eight-week (L8) periods, with a non-supplemented group (L0) as control. Antioxidant enzyme activities (SOD, T-AOC, GSH-Px) and innate immune parameters (ACP, ALP) were assayed, showing positive correlation with supplementation duration. Transcriptomic analysis revealed a time-dependent increase in differentially expressed genes (222 at four weeks vs. 760 at eight weeks). Gut microbiota profiling indicated modulation of bacterial abundance, notably increased Myroides, Kurthia, and Vagococcus. These results experimentally support an eight-week L-theanine regimen to optimize hepatopancreas metabolic function, immunity, and microbiota composition in crab aquaculture.