Tarmmikrobiota

Tarmmikrobiota (gut microbiota) refers to the community of microorganisms that inhabit the gastrointestinal tract of humans and other animals. It includes bacteria, archaea, viruses, and fungi, living in a complex ecosystem that interacts with host tissues and diet.

In humans, the majority are bacterial, with the dominant phyla typically Firmicutes and Bacteroidetes, along with smaller representations of Actinobacteria and Proteobacteria. The microbiota performs essential metabolic and protective roles, such as breaking down dietary fibers, fermenting substrates to short-chain fatty acids (butyrate, propionate, acetate), synthesizing vitamins, and helping metabolize bile acids. It also contributes to the development and regulation of the immune system and forms a barrier against invading pathogens.

Colonization begins at birth and continues to mature during early life, influenced by delivery mode, feeding, antibiotics, and environmental exposures. In adults, the microbiota tends to be relatively stable but remains dynamic, shifting with diet, illness, medications, and aging. Diet rich in fiber supports diversity and SCFA production, while high-fat or highly processed diets can alter composition.

Alterations in the gut microbiota, termed dysbiosis, have been associated with various conditions, including obesity, type 2 diabetes, inflammatory bowel disease, allergic and autoimmune disorders, and mental health changes via the gut-brain axis. Therapeutic approaches such as fecal microbiota transplantation, probiotics, and prebiotics aim to modulate the microbiota, but evidence varies by condition.

Researchers study the tarmmikrobiota using methods such as 16S rRNA gene sequencing, metagenomics, metabolomics, and transcriptomics to characterize composition and function. Understanding its role in health and disease continues to be an active field with potential for personalized nutrition and microbiome-targeted therapies.