Leaky gut syndrome describes increased intestinal permeability where the gut lining allows substances that are normally contained within the gut to pass into the bloodstream. This overview explains common symptoms, likely causes, and evidence-based natural strategies for supporting gut barrier function. For personalized microbiome insights, see the [InnerBuddies microbiome test](https://www.innerbuddies.com/blogs/gut-health/leaky-gut-syndrome-symptoms-causes-and-natural-remedies-innerbuddies). What is leaky gut? The intestinal lining normally acts as a selective barrier: it absorbs nutrients while blocking pathogens, toxins, and undigested food particles. When tight junctions between epithelial cells loosen, permeability increases and immune activation can follow. Persistent barrier dysfunction is associated with systemic inflammation and a range of symptoms, although research is ongoing to clarify causality and individual variability. Symptoms commonly attributed to increased gut permeability include digestive disturbances such as bloating, gas, diarrhea, and constipation. Extraintestinal symptoms often reported are chronic fatigue, cognitive difficulties (sometimes called "brain fog"), and inflammatory skin conditions like eczema or rashes. People may also notice new or worsening food sensitivities and allergic-type reactions. Multiple interacting factors contribute to barrier disruption. Diets high in processed foods, refined sugars, and certain food additives may negatively affect the gut lining and microbial balance. Chronic psychological stress and poor sleep alter immune and hormonal signaling, increasing susceptibility to permeability changes. Infections (bacterial, viral, or parasitic) and repeated or prolonged use of some medications, notably broad-spectrum antibiotics and nonsteroidal anti-inflammatory drugs, can also disrupt the mucosal barrier. Inflammation is both a driver and consequence of increased permeability. When molecules breach the barrier, the immune system responds with inflammatory mediators that can further damage epithelial cells and perpetuate permeability. Breaking this cycle is central to many natural healing strategies aimed at reducing inflammatory triggers and supporting mucosal repair. Natural approaches focus on diet, lifestyle, microbiome support, and, when appropriate, targeted supplementation. Emphasize whole, minimally processed foods, abundant fiber from vegetables, fruits, legumes, and whole grains, and fermented foods such as yogurt, sauerkraut, and kimchi to encourage beneficial microbes. Prioritizing sleep, stress management techniques (mindfulness, gentle movement, or breathing exercises), and regular physical activity supports systemic resilience. Some supplements studied for gut support include specific probiotic strains, omega-3 fatty acids, and L-glutamine for mucosal repair; clinical guidance is advised before beginning supplements. Testing can help characterize gut status and guide interventions. Laboratory markers used in clinical practice and research include zonulin and fecal calprotectin as indicators of permeability and intestinal inflammation—read about their interpretation at understanding zonulin and calprotectin. Microbiome composition analysis, including methods such as full-length 16S rRNA sequencing, can reveal microbial imbalances that may relate to barrier function. For those interested in product-specific information, a product page is available at InnerBuddies microbiome test product page. In summary, leaky gut is a multifactorial condition tied to barrier integrity, inflammation, and microbiome composition. A balanced, evidence-informed approach that combines dietary and lifestyle changes with targeted testing can help identify relevant factors and support recovery of gut health.