LA IMPORTANCIA DE LA FLORA INTESTINAL PARA LA SALUD FISICA Y MENTAL

Javier Santos, MD.Digestive Diseases Research UnitDepartment of Gastroenterology

Hospital Universitari Vall d'HebronUniversitat Autonoma de Barcelona

Barcelona, Spain

www.ir.vhebron.net/easyweb_irvh/RecercaHUVH/Digestiu/tabid/163/Default.aspx

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Last 5 years

Last 10 years

• The adult gut microbiotacontains up to 100 trillionmicro-organisms.

• 10 bacteria/somatic cell.• More than 3 million genes

(150 times more thanhuman genes).

• Microbiota can weigh upto 2 kg.

• One third of our gutmicrobiota is common tomost people, while twothirds are specific to eachone of us.

• In other words, the singleindividual gut microbiotais like an individualidentity card.

GUT MICROBIOTA

“The world is covered in a fine patina of feces”, Stanley Falkow“You want to keep your toothbrush a minimum of six feet away froma toilet”

GUT MICROBIOTA

• Food processing and apetite regulation: obesity and diabetes• Invasion resistance: IBD & IBS & Cl difficile• Immune and metabolic influence: manufacture neurotransmitters

(including serotonin), enzymes and vitamins (notably Bs and K),essential nutrients (including important amino acid and short-chain fatty acids), and a suite of other signaling molecules:autism & multiple sclerosis & autoimmune disorders

• Stress, behavior and temperament: “thinking with the gut”:anxiety & depression

• Trophic & homeostatic functions: intestinal development andregeneration, regulation of barrier permeability.

The gut microbes are looking after their own interests, chief among them getting

enough to eat and regulating the passage of food through their environment.

Prokaryotes and EukaryotesANIMALS:ü Accumulation of large numbers of genes in a separated nucleus, and low incidence of foreign gene uptakeü Ancestral loss of genes for biosynthesis of essential compounds (amino-acids and vitamins) and for harvesting energy from complex sources (Moran, Curr Biol 2006).ü Microbes evolve so much faster than we do, they can respond to changes in the environment with much greater speed and agility than “we” can. ü Exquisitely reactive and adaptive, bacteria can swap genes and pieces of DNA among themselves. This versatility is especially handy when a new toxin or food source appears in the environment. ü A common gut microbe in Japanese people has acquired a gene from a marine bacterium that allows them to digest seaweed, something the rest of us can’t do as well.

INVERSE RELATION BETWEEN THE INCIDENCE OFINFECTIOUS DISEASES AND IMMUNE DISORDERS

Bach JF, N Eng J Med 2002