Even when the amoebae ended up in a new site already replete with
resident bacteria, the farming amoebae «could still gain
by bringing preferred
bacteria... just as humans seed preferred plants in an already green world,» Brock and her colleagues wrote in the paper.
In a 2000 case that wasn't caused
by injection but brought important lessons about how fluids could move underground, hydrogeologists concluded that
bacteria - polluted water migrated horizontally underground for several thousand feet in just 26 hours, contaminating a drinking water well in Walkerton, Ontario, and sickening thousands of
residents.
GF mice have been shown to have increased plasma tryptophan concentrations, 47, 48 which can be normalized following post-weaning colonization.47
Resident gut
bacteria can utilize tryptophan for growth229 and in some cases, production of indole, 230, 231 or serotonin (reviewed
by O'Mahony and colleagues95), while the microbiota might also affect tryptophan availability by influencing host enzymes responsible for its degradation.47 By limiting the availability of tryptophan for serotonin production in the CNS (EC - derived serotonin does not cross the BBB), the gut microbiota could influence serotonergic neurotransmission.95 In vulnerable populations, reducing the circulating concentrations of tryptophan has been shown to affect mood, and to reinstate depressive symptoms in patients who have successfully responded to selective serotonin reuptake inhibitors.232, 233 The gut microbiota could also influence the production of both neuroprotective and neurotoxic components of the kynurenine pathway.2
by O'Mahony and colleagues95), while the microbiota might also affect tryptophan availability
by influencing host enzymes responsible for its degradation.47 By limiting the availability of tryptophan for serotonin production in the CNS (EC - derived serotonin does not cross the BBB), the gut microbiota could influence serotonergic neurotransmission.95 In vulnerable populations, reducing the circulating concentrations of tryptophan has been shown to affect mood, and to reinstate depressive symptoms in patients who have successfully responded to selective serotonin reuptake inhibitors.232, 233 The gut microbiota could also influence the production of both neuroprotective and neurotoxic components of the kynurenine pathway.2
by influencing host enzymes responsible for its degradation.47
By limiting the availability of tryptophan for serotonin production in the CNS (EC - derived serotonin does not cross the BBB), the gut microbiota could influence serotonergic neurotransmission.95 In vulnerable populations, reducing the circulating concentrations of tryptophan has been shown to affect mood, and to reinstate depressive symptoms in patients who have successfully responded to selective serotonin reuptake inhibitors.232, 233 The gut microbiota could also influence the production of both neuroprotective and neurotoxic components of the kynurenine pathway.2
By limiting the availability of tryptophan for serotonin production in the CNS (EC - derived serotonin does not cross the BBB), the gut microbiota could influence serotonergic neurotransmission.95 In vulnerable populations, reducing the circulating concentrations of tryptophan has been shown to affect mood, and to reinstate depressive symptoms in patients who have successfully responded to selective serotonin reuptake inhibitors.232, 233 The gut microbiota could also influence the production of both neuroprotective and neurotoxic components of the kynurenine pathway.224