Are bacteria making you hungry?

(scienceinfo.net) - More than half a decade ago, becoming more and more clear that normal gastrointestinal bacteria (GI - gastrointestinal) play a very important role in the biology of humans and animals other. Currently Vic Norris of Rouen University, France, and co-authors propose another role for GI bacteria: they cause some control of the host's appetite. The researchers' assessment was published online before the print edition in the Journal of Bacteriology.

This hypothesis is based on the majority of observations of the number of bacteria roles known to the host's biology, as well as their relationship to the host's system."Bacteria have just realized and synthesized hormonal hormones , " Norris wrote. "This leads to the hypothesis that the intestinal bacteria consists of a community, which forms an organ of isolated microorganisms with the mammalian nervous system that this nervous system distributes. The nerves of the digestive tract ". (That's the nervous system that distributes the nerves of the digestive tract called the "intestinal nervous system . " This system contains about half a billion neurons, compared to 85 billion neurons in the system. Central neutral system).

"The intestinal microbiota reacts to both the nutrients consumed by their hosts and the host state when signaled by various hormones," Norris et al wrote. Information transmission is probably both ways: they also produce compounds used for signaling in the human system, 'including neurotransmitters like GABA, amino acids such as tyrosine and tryptophan - which can be converted into molecules that determine mood, dopamine and serotonin " and many other things, Norris said.

Moreover, it is becoming increasingly clear that intestinal bacteria can play a role in diseases such as cancer, metabolic syndrome, thyroid disease, through their effects on host signaling. They may even affect mood disorders, according to recent pioneering studies, through dopamine and appetite-related peptides. Gut bacteria Campilobacter jejuni has been shown to be involved in induction of anxiety in mice, Norris said.

But does the intestinal flora actually use its ability to influence food choices? The researchers propose a series of experiments that can help answer this question, including epidemiological studies, and "experiment the correlation between the special presence of bacterial metabolites. with active images of brain regions associated with appetite and pleasure ".