Dysbiosis

Dysbiosis refers to an imbalance in the composition or function of the microbial communities (microbiome) that live in and on your body — most commonly referring to the gut microbiome, which contains trillions of bacteria, viruses, fungi, and other microorganisms in the digestive tract. In a healthy state, beneficial microbes outnumber and keep potentially harmful microbes in check. Dysbiosis occurs when this balance is disrupted, allowing harmful species to proliferate or reducing the diversity of beneficial species.

The gut microbiome plays critical roles far beyond digestion. It produces vitamins (K, B12, biotin), trains the immune system, maintains the intestinal barrier, produces neurotransmitters (including about 90% of the body's serotonin), metabolizes drugs and dietary compounds, and communicates with the brain through the gut-brain axis. When dysbiosis disrupts these functions, the effects can extend far beyond the digestive system.

Common causes of dysbiosis include antibiotic use (which can indiscriminately kill beneficial bacteria alongside harmful ones), a diet high in processed foods and low in fiber, chronic stress, excessive alcohol consumption, infections, and certain medications like proton pump inhibitors. The consequences can range from digestive symptoms like bloating, diarrhea, and constipation to systemic effects including inflammation, weakened immunity, and even mood disturbances.

Dysbiosis is increasingly recognized as a contributing factor in many chronic diseases. If you experience persistent digestive symptoms, unexplained immune issues, or mood changes — especially following antibiotic use or significant dietary changes — your healthcare provider may consider dysbiosis as a contributing factor. Testing options include stool analysis (comprehensive digestive stool analysis or 16S rRNA sequencing) that can characterize your gut microbiome composition.

Restoring microbial balance typically involves dietary changes (increasing fiber, fermented foods, and plant diversity), potentially using probiotics or prebiotics, reducing unnecessary antibiotic use, managing stress, and in some cases, fecal microbiota transplantation (FMT) for severe conditions like recurrent C. difficile infection.