The researchers also gave the mice stress ...

Friendship intestinal bacteria not only to keep the gut happy, they can help keep their boss happy, too, a new study in mice finds. Mice fed a broth enriched type of friendly intestinal bacteria called Lactobacillus rhamnosus feel less anxious than broth mice fed without bacteria. These changes in behavior were accompanied by differences in the levels of brain chemical sensors and stress hormones. Bacteria telegraph these brain-chemical and behavioral change messages via the vagus nerve, which connects the brain stem to different internal organs, the researchers reported online Aug. 29 in

Proceedings of the National Academy of Sciences. Some studies have shown that changing the mix of bacteria in the gut can influence the behavior of (). A new study goes a step further to examine how these changes took place, said Paul Patterson, neuroimmunologist the California Institute of Technology in Pasadena, California BЂњMost people havenBЂ ™ t go so far as to look at what is happening with whatBЂ ™ to brain BЂ "he says. The research team BЂ "led by John Bienenstock of McMaster University in Hamilton, Canada, and John Cryan from University College Cork in Ireland BЂ" looked at the brains miceBЂ ™ s to study the level of GABA receptor, a protein that reacts and feels important chemical Messenger of the brain called GABA. Changes in the way of GABA and other brain chemical systems work affect behavior. Mice were fed bacteria containing broth was a high level of receptor protein in some parts of the brain, and lower levels in other regions than in mice that received sterile broth. Mice usually stay near the walls, and those that eat bacteria spend more time in open spaces in a special maze BЂ "measure, which tells scientists mice less anxious than usual. The researchers also gave the mice stress tests, forcing animals to swim in the water tank. Stressed mice that ate

Lactobacillus rhamnosus had lower levels of stress hormones than the mice that ate only soup. When the researchers severed the vagus nerve, the mouse will not change the level of GABA receptors and didnBЂ ™ t shows the differences of behavior that the nerve is probably the main route microflora to pass information to the brain. Vagus nerve BЂњis obvious way, but thatBЂ ™ not say itBЂ ™ s the only route BЂ "says Bienenstock. Messages can be transmitted through other nerves or chemicals in the blood. Researchers still donBЂ ™ know that the idea to send bacteria into the brain or bacterial additives may be important in regulating behavior peopleBЂ ™ s. Some researchers have suggested, based on experiments in mice, that bacteria of the intestine may play a role in a variety of brain and mental disorders such as depression, anxiety, autism and schizophrenia. But BЂњone must be careful. This exciting science in rodents, but canBЂ ™ t simply extrapolated to people BЂ «Emeran says Mayer, a gastroenterologist and a neurologist in UCLABЂ ™ s Center for Neurobiology of stress, which is not involved in the new study. Drugs and food companies that make probiotics BЂ "beneficial bacteria taken in tablets or eat like yogurt BЂ" hope that the products can help alleviate strattera depression, improve weight loss and treatment of other conditions, but there is no evidence in humans that probiotics can achieve these goals, says Mayer. BЂњItBЂ ™ almost like science fiction, and you can imagine most amazing thing, because so little is known about it, BЂ, "he says. But BЂњSo far thereBЂ ™ really is no evidence that probiotics affect human emotions. BЂ "

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