How the gut barrier changes with age
A research-supply overview of age-related changes in intestinal barrier function, covering the molecular components, models, and interventions studied in the laboratory.
How the gut barrier changes with age
The intestinal barrier is a dynamic system comprising the mucus layer, epithelial cells, and intercellular tight junctions, which together regulate paracellular permeability. Its functional integrity declines with age, a process termed 'leaky gut' or increased intestinal permeability. This decline is characterized by reduced mucus thickness, altered tight junction protein expression, and increased translocation of luminal antigens. The phenomenon is observed across species, including humans, rodents, and dogs [9].
Research into age-related barrier dysfunction centers on the aryl hydrocarbon receptor (AHR) pathway, which orchestrates mucosal immunity and epithelial repair [6]. Other pathways under investigation include mitochondrial function and microbial metabolite signaling [2][5].
Research Studies
Alpha-ketoglutarate and mitochondrial protection in CKD mice
In a study using male C57BL/6 mice with adenine-induced chronic kidney disease (CKD), oral administration of 2% alpha-ketoglutarate (AKG) for 28 days was investigated. The study aimed to assess AKG's effects on CKD and potential mechanisms involving mitochondrial protection, gut microbiota, and metabolite remodeling. The findings indicated that AKG alleviated CKD in this model, with observed changes in gut barrier function and microbial composition [2].
Urolithin A and AHR-NLRP6 signaling in intestinal epithelial cells
Urolithin A (UroA), a microbial metabolite, was shown to activate the AHR in mouse intestinal epithelial cells (IEC), leading to NLRP6 inflammasome activation and release of interleukin (IL)-18, but not IL-1β. This UroA-induced IL-18 was critical for IL-22 production, mucin 2 expression, and strengthening of gut barrier integrity in mouse models [6].
Urolithin A and protection against arsenic-induced barrier dysfunction in humanized AS3MT mice
In humanized AS3MT mice exposed to inorganic arsenic (iAs), UroA protected against iAs-induced gut barrier dysfunction. The study demonstrated that UroA mitigated cytotoxicity, apoptosis, oxidative stress, and ROS production in vitro, and in vivo, it reduced barrier permeability and modulated the gut microbiota [5].
Glutamine and sex-dependent effects on gut barrier in diet-induced obesity
Male and female C57BL/6 mice with high-fat-diet-induced obesity received oral glutamine (2 g/kg/day) in drinking water from week 12 to 14. The study found opposite metabolic and gut responses between sexes. In males, glutamine supplementation improved intestinal permeability and glycemic control, while in females, it exacerbated barrier dysfunction and metabolic parameters [4].
Yeast protein supplementation and gut barrier function during GLP-1RA-induced weight loss
An ongoing clinical trial (NCT07817823) is evaluating whether yeast protein supplementation can preserve lean body mass and muscle function in adults with overweight or obesity receiving GLP-1 receptor agonist (GLP-1RA) treatment. Secondary outcomes include effects on gut barrier function, gut microbiota, and related metabolites. The study compares yeast protein with whey protein and a combination [1].
Probiotic intervention and digestive health in obese patients initiating GLP-1RA treatment
A clinical trial (NCT07213323) is investigating probiotic supplementation for digestive health in obese patients starting GLP-1RA therapy. The study addresses gastrointestinal adverse events associated with GLP-1RAs, such as nausea, vomiting, diarrhea, and abdominal pain, and aims to assess changes in gut barrier function and microbiota [3].
Postbiotic supplementation and gut barrier in irritable bowel syndrome
A completed single-arm, open-label study (NCT07699926) evaluated PosBion® postbiotic supplementation in adults with irritable bowel syndrome (IBS) over 12 weeks. The study assessed changes in IBS symptom severity, quality of life, gastrointestinal health, inflammatory markers, and gut barrier function [8].
Gut microbiome-hormone interactions and early cardiovascular risk in adolescents
A narrative review summarized research on the diet-microbiome-hormone axis in adolescents, focusing on microbial metabolites such as short-chain fatty acids (SCFAs) and transformed bile acids. These metabolites regulate enteroendocrine communication, insulin sensitivity, vascular function, and inflammatory tone, linking dietary factors to gut barrier and metabolic health during development [7].
Comparative effects of interventions on gut barrier function
| Intervention | Model | Key findings on gut barrier |
|---|---|---|
| Alpha-ketoglutarate | CKD mice | Alleviated CKD, improved barrier function, modulated microbiota [2] |
| Urolithin A | Mouse IEC, humanized AS3MT mice | Activated AHR-NLRP6-IL-18 axis, strengthened barrier, protected against arsenic [5][6] |
| Glutamine | Male and female obese mice | Sex-dependent effects: improved barrier in males, worsened in females [4] |
| Yeast protein | Adults on GLP-1RA (ongoing) | Assessing effects on gut barrier and microbiota [1] |
| Probiotic | Obese patients on GLP-1RA (ongoing) | Assessing digestive health and barrier function [3] |
| Postbiotic (PosBion®) | Adults with IBS (completed) | Evaluated barrier function and inflammation [8] |
If you are reading this for personal health reasons
The compounds and interventions described here are sold for laboratory research use only. We do not provide dosing, medical guidance, or recommendations for personal use. Anyone considering a compound for themselves should speak to a licensed clinician.
Sources
- [1] Yeast Protein Supplementation and Muscle Preservation During GLP-1RA-Induced Weight Loss
- [2] Alpha-ketoglutarate alleviates chronic kidney disease via mitochondrial protection, gut microbiota, and metabolite remodeling.
- [3] Probiotic Intervention for Digestive Health in Obese Patients Initiating GLP-RA Treatment
- [4] Opposite metabolic and gut responses to oral glutamine in male and female mice with diet-induced obesity.
- [5] Microbial metabolite Urolithin A protects against inorganic arsenic-induced gut barrier dysfunction in humanized AS3MT mice.
- [6] Urolithin A activates aryl hydrocarbon receptor-NLRP6-mediated pathways in intestinal epithelial cells to modulate mucosal immunity and strengthen gut barrier integrity.
- [7] Gut Microbiome-Hormone Interactions and Precision Fermentation in the Prevention of Early Cardiovascular Risk in Adolescents.
- [8] Efficacy of PosBion® Postbiotic Supplementation in Adults With Irritable Bowel Syndrome
- [9] Metabolic and endocrine modulation of the gut-adipose tissue axis via pro-, pre-, and postbiotics in overweight dogs: A systematic review.
- [10] Evaluation of dietary curcumin-loaded mesoporous silica nanoparticles on growth, blood biochemistry, gut barrier integrity and enteric gas emissions in weaned piglets.
- [11] Antibacterial hyaluronic acid hydrogel with sustained release of larazotide as effective colitis treatment.