Maternal probiotic intake attenuates ileal Crh receptor gene expression in maternally separated rat offspring

Area of Science:

• Neuroendocrinology
• Gastroenterology
• Microbiome research

Background:

• Corticotropin-releasing hormone (Crh) and its receptors (Crhr) play a key role in mediating stress responses, including gastrointestinal dysfunctions.
• Neonatal stress paradigms, such as maternal separation (MS), are known to induce long-term alterations in the neuroendocrine system and gut physiology.
• Sex-specific differences in stress responses and gut function have been reported in various species.

Purpose of the Study:

• To investigate the impact of neonatal maternal separation (MS) on the expression of corticotropin-releasing hormone receptors (Crhr1 and Crhr2) in the ileum of young and adult rat offspring.
• To examine the effects of adult stress exposure on ileal Crhr expression in a sex-dependent manner.
• To evaluate the potential of maternal probiotic intervention as an early prophylactic strategy against stress-induced alterations in gut Crhr expression.

Main Methods:

• Neonatal maternal separation (MS) was employed as a stress paradigm in rat pups.
• Quantitative real-time PCR was used to measure ileal Crhr1 and Crhr2 transcript quantities.
• Rats were exposed to either MS or adulthood restraint stress, with or without prior maternal probiotic intervention.

Main Results:

• Neonatal MS significantly increased ileal Crhr1 transcript quantities in young rat offspring.
• Exposure to MS or adulthood restraint stress led to increased ileal Crhr1 and Crhr2 transcript quantities specifically in adult female offspring.
• Maternal probiotic intervention effectively reversed the stress-induced overexpression of Crhr in the offspring's ileum.

Conclusions:

• Neonatal maternal separation induces lasting changes in gut corticotropin-releasing hormone receptor expression, particularly in females.
• Stress-induced alterations in gut Crhr expression can be sex-specific.
• Maternal probiotic administration represents a promising early-life intervention to mitigate the long-term gastrointestinal consequences of stress.