Exposure to a social stressor disrupts the community structure of the colonic mucosa-associated microbiota

Abstract

BackgroundThe microbiota of the mammalian gastrointestinal (GI) tract consists of diverse populations of commensal bacteria that interact with host physiological function. Dysregulating these populations, through exogenous means such as antibiotics or dietary changes, can have adverse consequences on the health of the host. Studies from laboratories such as ours have demonstrated that exposure to psychological stressors disrupts the population profile of intestinal microbiota. To date, such studies have primarily focused on prolonged stressors (repeated across several days) and have assessed fecal bacterial populations. It is not known whether shorter stressors can also impact the microbiota, and whether colonic mucosa-associated populations can also be affected. The mucosa-associated microbiota exist in close proximity to elements of the host immune system and the two are tightly interrelated. Therefore, alterations in these populations should be emphasized. Additionally, stressors can induce differential responses in anxiety-like behavior and corticosterone outputs in variant strains of mice. Thus, whether stressor exposure can have contrasting effects on the colonic microbiota in inbred C57BL/6 mice and outbred CD-1 mice was also examined.ResultsIn the present study, we used high throughput pyrosequencing to assess the effects of a single 2-hour exposure to a social stressor, called social disruption (SDR), on colonic mucosa-associated microbial profiles of C57BL/6 mice. The data indicate that exposure to the stressor significantly changed the community profile and significantly reduced the relative proportions of two genera and one family of highly abundant intestinal bacteria, including the genus Lactobacillus. This finding was confirmed using a quantitative real-time polymerase chain reaction (qPCR) technique. The use of qPCR also identified mouse strain-specific differences in bacterial abundances. L. reuteri, an immunomodulatory species, was decreased in stressor-exposed CD-1 mice, but not C57BL/6 mice.ConclusionsThese data illustrate that stressor exposure can affect microbial populations, including the lactobacilli, that are closely associated with the colonic mucosa. Because the lactobacilli can have beneficial effects on human health, stressor-induced reductions of their population could have important health implications.

The structures of the colonic mucosa-associated and luminal microbial communities are distinct and differentially affected by a prolonged murine stressor

“…19,42,43 However, the finding that colonic mucosa-associated lactobacilli are reduced in mice exposed to the chronic restraint stressor is consistent with a previous study in as little as one 2-hour exposure to a social stressor significantly reduced the relative abundance of colonic mucosa-associated Lactobacillus in C57BL/6 and CD-1 mice. 44 Thus, it is apparent that stressor exposure reduces mucosa-associated, but not luminal, lactobacilli in laboratory mice. Additional studies are needed to confirm and extend these findings in higher mammals.…”

Sex differences in the gut microbiome–brain axis across the lifespan

“…R. Soc. B 371: 20150122 and cytokines into circulation [153][154][155][156][157][158]. Interestingly, these physiological responses and the composition of microbial communities return to baseline following cessation of stressors, suggesting increased resilience to environmental challenges during adulthood [159].…”

Natural zeolite (chabazite/phillipsite) dietary supplementation influences faecal microbiota and oxidant status of working dogs

“…Faeces consistency was scored by a single operator using a scale of 1 (hard) to 5 (watery), on days 0 and 29 (Grieshop et al 2002). Individual faecal samples were collected directly from the rectum, using a sterile glove lubricated with water on day 0 and within two hours from the end of the trial test (Galley et al 2014). The faeces were placed in sterile polyethylene bags, and immediately transported to the laboratory on ice packs.…”

“…These effects may be both due to a prolonged and an acute exercise. In short-lasting acute stressors, changes of the number of bacteria shed in the stool and of some populations of the colonic mucosa-associated microbiota are reported (Galley et al 2014). …”

“…Stressor exposure may impact the stability of the intestinal microbiota (Galley et al 2014). A bidirectional neurohumoral communication system, known as the gut-brain axis, integrates the host gut and brain activities.…”