Gut microbiota linked to HPA axis hormones

ORLANDO, Fla. — Specific microbacteria in the human gut are associated with hormones of the hypothalamic–pituitary–adrenal axis, and the associations vary with substance use and type 2 diabetes, according to findings of a cross-sectional study.

“The data from our group suggest that gut microbiota is associated with metabolic, pituitary and brain functions. The data show, for example, that lower levels of Bifidobacteria and some other [gamma-amino butyric acid]-producing bacteria are related to diabetes and substance use,” Elena Barengolts, MD, associate professor of medicine at the University of Illinois at Chicago and chief of the section of endocrinology at the Jesse Brown VA Medical Center, told Endocrine Today.

Elena Barengolts

Barengolts and colleagues analyzed the microbiota composition of stool samples and measured levels of hypothalamic–pituitary–adrenal (HPA) hormones from 99 black male veterans. Of the cohort, 95% had a chronic health condition, 66% had a psychiatric condition, 49% had type 2 diabetes and 44% had a history of alcohol and drug use.

Comparing the lowest and highest tertiles for hormones, researchers found positive associations for oxytocin with Dialister (P = .039) and Prevotella bacteria (P = .052) and negative associations for insulin-like growth factor I with Bifidobacterium (P = .018) and Parabacteroides distasonis (P = .042). Cortisol was positively associated with Catenibacterium (P = .003), Prevotella stercorea (P = .027) and P. copri (P = .058) and negatively associated with Bacteroides (P = .021).

Bifidobacterium was negatively associated with diabetes and substance use (P < .001), and that relationship remained significant after adjustment.

All associated bacteria except one produce gamma-amino butyric acid, a neurotransmitter important in the pathophysiology of type 2 diabetes and psychiatric disorders, the researchers noted, suggesting that certain gut microbes may serve as probiotic or psychobiotic therapies for these disorders.

“Previous research has shown that Bifidobacteria is disproportionately important for human health relative to its lower abundance in the gut,” Barengolts said. “During life, the numbers of gut Bifidobacteria decrease from up to 90% in breast-fed babies to less than 5% in older adults and in patients with some conditions, including obesity and diabetes. Some foods, supplements and exercise appear to promote beneficial bacteria. ... The microbiota-related research has vastly expanded, but many questions await answers. Today, though, the recommendation remains simple: Healthy lifestyle is the best answer to healthy ‘gut instinct’.”- by Jill Rollet

Reference:

Barengolts E, et al. Abstract LB SAT 60. Presented at: The Endocrine Society Annual Meeting; April 1-4, 2017; Orlando, Fla.

Disclosures: Barengolts reports no relevant financial disclosures.