Specific Changes in the Mammalian Gut Microbiome as a Biomarker for Oxytocin-Induced Behavioral Changes

Abstract

Prolonged exposure to psychiatric pharmacological agents is often associated with marked gastrointestinal phenomena, including changes in food intake, bowel motility, gastric emptying, and transit time. Those changes are reflected in the gut microbiota composition of the patient and can, therefore, be objectively measured. This is in contrast to the standard psychiatric evaluation of patients, which includes symptoms that are subjectively assessed (i.e., mood, anxiety level, perception, thought disorders, etc.). The association between a drug’s effect on the microbiota and psychiatric symptoms may allow for quantifiable surrogate markers of treatment effectiveness. Changes in the levels of specific drug-sensitive bacterial species can, thus, potentially serve as biomarkers for the intake and effectiveness of psychiatric drugs. Here, we show substantial microbiota changes that were associated with oxytocin administration and the decreased anxiety/depression-like behaviors it conferred in a rat model of corticosterone-induced stress. Compared with oxytocin, citalopram produced more minor effects on the rats’ microbiota. Alterations in the gut microbiota may, therefore, reflect the consumption and effectiveness of some psychiatric drugs.

Microbes, oxytocin and stress: Converging players regulating eating behavior

“…A recent study shows alterations in gut microbiota composition after Oxt administration. In the study by Dangoor et al 11 Oxt administration led to altered gut microbiota diversity, which was linked with a decrease in anxiety‐ and depression‐like behaviors in a corticosterone (CORT)‐induced stress rat model 11 …”

“…Oxt has also been investigated for its potential interaction with the human microbiota 10 . This hormone seems to both impact and be modulated by the microbiome 11–13 . For instance, Oxt administration (10 IU SC/animal/day, 14 days), induced changes in the gut microbiota composition in rats and was associated with overall improvement in stress, and anxiety/depression‐like behaviors 11 .…”

“…This hormone seems to both impact and be modulated by the microbiome 11–13 . For instance, Oxt administration (10 IU SC/animal/day, 14 days), induced changes in the gut microbiota composition in rats and was associated with overall improvement in stress, and anxiety/depression‐like behaviors 11 . Noteworthy, the probiotic Limosilactobacillus reuteri (formerly known as Lactobacillus reuteri ) has been shown to not only increase circulating Oxt levels 12 but also Oxt expression in the brain 13 in rodents, effects which have been linked with metabolism, 14,15 wound healing, 12 sociability and behavior 14,16,17 .…”

Antibiotics and mental health: The good, the bad and the ugly

“…[ 98 ] found that plasma oxytocin levels were reduced compared to individuals without a mood disorder and oxytocin has been reported as possessing prosocial effects [ 99 ]. There is increasing evidence from rodent studies that gut microbes can alter oxytocin levels, and early exposure to antibiotics may increase the risk of autism [ 100 , 101 , 102 ]. In a study in mice, Desbonnet et al.…”

Earth Dreams: Reimagining ARPA for Health of People, Places and Planet

“…Since the gut microbiome modulates local and systemic immune function, and has been implicated in most NCDs, it should be little surprise that gut (as well as oral, and lung) microbiota are emerging as a factor in determining COVID-19 susceptibility, severity and survivability [ 95 , 96 , 97 ]. Furthermore, the efficacy of biological treatments, including breakthrough drug candidates, the sort imagined by ARPA-H, may also be determined by the very microbiome that is shaped by the lived experience [ 98 , 99 , 100 , 101 ].…”