suolistomikrobisto

Suolistomikrobisto, or gut microbiota, denotes the community of microorganisms inhabiting the gastrointestinal tract. It includes bacteria, archaea, viruses, and fungi, with bacteria forming the majority. In an adult, it is estimated to weigh about 1 to 2 kilograms and to comprise roughly 10^13 to 10^14 cells, though numbers vary between individuals and over time. The most abundant bacterial groups belong to the phyla Firmicutes and Bacteroidetes, with smaller contributions from Actinobacteria, Proteobacteria, and others.

Its activities influence digestion and metabolism, including breakdown of complex carbohydrates that human enzymes cannot digest, producing short-chain fatty acids (butyrate, propionate, acetate) that support colon health and energy balance. It also participates in vitamin synthesis, aids immune system development and regulation, and helps maintain the gut barrier against pathogens. The microbiota communicates with other organs via the microbiota–gut–brain axis and metabolic signaling.

Composition is shaped by factors such as mode of birth, early feeding, diet, antibiotic exposure, age, geography, and health status. The microbiota tends to become relatively stable after early childhood but remains capable of change throughout life in response to diet, illness, or treatment.

Research uses sequencing-based approaches (16S rRNA gene sequencing, metagenomics) to characterize who is present and what they can do, while metabolomic and transcriptomic methods study activity. Dysbiosis, an imbalance of microbial communities, has been associated with several conditions including obesity, metabolic syndrome, inflammatory bowel disease, and allergies; causality and mechanisms remain active areas of study. Therapeutic strategies such as probiotics, prebiotics, and fecal microbiota transplantation are explored, with evidence strongest for certain indications.