Effect of maternal probiotic intervention on HPA axis, immunity and gut microbiota in a rat model of irritable bowel syndrome.
OBJECTIVE
To examine whether maternal probiotic intervention influences the alterations in the brain-immune-gut axis induced by neonatal maternal separation (MS) and/or restraint stress in adulthood (AS) in Wistar rats.


METHODS
Dams had free access to drinking water supplemented with Bifidobacterium animalis subsp lactis BB-12® (3 × 10(9) CFU/mL) and Propionibacterium jensenii 702 (8.0 × 10(8) CFU/mL) from 10 days before conception until postnatal day (PND) 22 (weaning day), or to control ad lib water. Offspring were subjected to MS from PND 2 to 14 or left undisturbed. From PND 83 to 85, animals underwent 30 min/day AS, or were left undisturbed as controls. On PND 24 and 86, blood samples were collected for corticosterone, ACTH and IgA measurement. Colonic contents were analysed for the composition of microflora and luminal IgA levels.


RESULTS
Exposure to MS significantly increased ACTH levels and neonatal fecal counts of aerobic and anaerobic bacteria, E. coli, enterococci and clostridia, but reduced plasma IgA levels compared with non-MS animals. Animals exposed to AS exhibited significantly increased ACTH and corticosterone levels, decreased aerobic bacteria and bifidobacteria, and increased Bacteroides and E. coli counts compared to non-AS animals. MS coupled with AS induced significantly decreased anaerobes and clostridia compared with the non-stress adult controls. Maternal probiotic intervention significantly increased neonatal corticosterone levels which persisted until at least week 12 in females only, and also resulted in elevated adult ACTH levels and altered neonatal microflora comparable to that of MS. However, it improved plasma IgA responses, increased enterococci and clostridia in MS adults, increased luminal IgA levels, and restored anaerobes, bifidobacteria and E. coli to normal in adults.


CONCLUSIONS
Maternal probiotic intervention induced activation of neonatal stress pathways and an imbalance in gut microflora. Importantly however, it improved the immune environment of stressed animals and protected, in part, against stress-induced disturbances in adult gut microflora.
Laboratory of Microbiology, School of Environmental and Life Sciences, the University of Newcastle, Callaghan, New South Wales, Australia. Javad.Barouei@uon.edu.au
Javad
J
Barouei
Mahta
M
Moussavi
Deborah M
DM
Hodgson
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D001644:Bifidobacterium; D003345:Corticosterone / Q000097:blood; D017931:DNA Primers; D005260:Female; D007070:Immunoglobulin A / Q000097:blood; D007422:Intestines / Q000276:immunology* / Q000382:microbiology*; D008297:Male; D019936:Probiotics; D011424:Propionibacterium; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction
D017931:DNA Primers; D007070:Immunoglobulin A; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone