Tarmflora, eller gut microbiota på engelsk, mikrobiota, microbiome, er en samlebetegnelse for de ulike typer bakterier som lever i tarmen vår. Mikrobiota har mange livsviktige funksjoner i kroppen.
I den vitenskapelige litteraturen omtales tarmflora som «gut microbiota». Den normale tarmfloraen inneholder over 1000 bakteriearter, men hos mennesker dominerer fire hovedtyper eller bakterielle fyla: Actinobacteria, Bacteroidetes, Firmicutes og Proteobacteria. Dette skriver norsk egetidsskriftet Gastroenterologen.no, i en artikkel om tarmflora, mikrobiota, løselig og uløselig kostfiber, pro- og prebiotika, og utvikling av fedme – les hele her .
Les også: Lekk tarm – symptomer, tester og kosthold
Forskning om tarmflora og kosthold
Under er et lite utvalg av forskning om kosthold og bakteriesammensetningen i tarmen.
Harvard Universitet beskriver ulike typer prebiotika slik:
Harvard universitet skriver på sine nettsider om kostholdet for sunn tarmflora og tarmbakterier.
«Foods that support increased levels of SCFA are indigestible carbohydrates and fibers such as inulin, resistant starches, gums, pectins, and fructooligosaccharides.»
«The highest amounts are found in raw versions of the following: garlic, onions, leeks, asparagus, Jerusalem artichokes, dandelion greens, bananas, and seaweed. In general, fruits, vegetables, beans, and whole grains like wheat, oats, and barley are all good sources of prebiotic fibers.»
«Probiotic foods contain beneficial live microbiota that may further alter one’s microbiome. These include fermented foods like kefir, yogurt with live active cultures, pickled vegetables, tempeh, kombucha tea, kimchi, miso, and sauerkraut.»
Flere kilder og sitater
En forskningsrapport publisert i tidsskriftet Alimentary Pharmacology and Therapeutics:
«Results: Studies found evidence of fibre-influenced differences in the microbiome and metabolome as a consequence of habitual diet, and of long-term or short-term intervention (in both animals and humans).»
«Short-term diets can also have major effects, particularly those exclusively animal-based, and those high-protein, low-fermentable carbohydrate/fibre ‘weight-loss’ diets, increasing the abundance of Bacteroides and lowering Firmicutes, with long-term adherence to such diets likely increasing risk of colonic disease.»
Kilde: H. L. Simpson & B. J. Campbell, Review article: dietary fibre–microbiota interactions. Alimentary Pharmacology and Therapeutics 2015.
En studie publisert i tidsskriftet Gut under British Medical Journal Group:
«A healthy gut microbiota plays a role in health, but imbalances can become pathological, increasing inflammation and contributing to metabolic dysfunction. Diet plays a significant role in shaping the composition and function of the microbiota.
Eating patterns high in fruits, vegetables, whole grains, and legumes promote the abundance of healthier bacteria that produce short-chain fatty acids and other health-promoting metabolites.»
Kilde: Jardine M. Nutrition considerations for microbiota health in diabetes. Diabetes Spectrum. 2016;29:238-244. Lenke til studien er her
I denne artikkelen kan vi lese om tarmflora og forstyrrelser i immunsystemet:
«The microbiota plays a fundamental role on the induction, training and function of the host immune system. In return, the immune system has largely evolved as a means to maintain the symbiotic relationship of the host with these highly diverse and evolving microbes. When operating optimally this immune system–microbiota alliance allows the induction of protective responses to pathogens and the maintenance of regulatory pathways involved in the maintenance of tolerance to innocuous antigens.
However, in high-income countries overuse of antibiotics, changes in diet, and elimination of constitutive partners such as nematodes has selected for a microbiota that lack the resilience and diversity required to establish balanced immune responses. This phenomenon is proposed to account for some of the dramatic rise in autoimmune and inflammatory disorders in parts of the world where our symbiotic relationship with the microbiota has been the most affected»
Les også hva Harvard universitet skriver om kosthold og immunitet på sine nettsider
En metaanalyse om tarmflora og depresjon: lenke
En metaanalyse og tarmflorasammensetning: lenke