Probiotics reduce repeated water avoidance stress-induced colonic microinflammation in Wistar rats in a sex-specific manner

Abstract

The colonic response to stress is greater in female rats than in male rats. The aim of this study was to evaluate the effect of probiotics in the repeated water avoidance stress (rWAS)-induced colonic microinflammation model of Wistar rats in a sex-specific manner. The three groups (no-stress, WAS, and WAS with probiotics) were exposed to r-WAS for 1 h daily for 10 days, and Lactobacillus farciminis was administered by oral gavage for 10 days to animals in the probiotics group. The visceromotor response (VMR) to colorectal distension (CRD) was assessed using a barostat and noninvasive manometry before and after WAS exposure. Immunohistochemistry for mast cells and real-time polymerase chain reaction (RT-PCR) for detection of mucosal cytokines were performed using distal colon tissue after the animals were sacrificed. Significant reduction of VMR to CRD (visceral analgesia) was observed at 60 mmHg in the female WAS group (P = 0.045), but not in males. In addition, the female WAS with probiotics group showed a significantly lower colonic mucosal mast cell count in comparison to the female WAS group (P = 0.013), but this phenomenon was not observed in the male group. The colonic mucosal mRNA levels of interferon-γ (IFNR), tumor necrosis factor-α (TNFA), interleukin (IL) 6, and IL17 were higher in the female WAS group than in the male WAS group. The mRNA levels of IFNR, TNFA, and IL6 were significantly decreased in WAS females who received probiotics (all P < 0.050). In conclusion, rWAS is induced in a sex-specific manner. A 10-day-long treatment with L. farciminis is an effective therapy for rWAS-induced colonic microinflammation in female rates, but not in male rats.

Stress and the gut microbiota-brain axis

“…Another Lactobacillus, L. fermentum, increased exploratory behavior in an elevated plus maze, and reduced permeability in the small intestine and stress-induced by WAS and MS model (Vanhaecke et al, 2017). It is also interesting to note that probiotics seems to be a sex depended effect due to reduced WAS-induced colonic microinflammation in female rates but not in male rats (Lee et al, 2017).…”

Ephrin‐B2 signaling in the spinal cord as a player in post‐inflammatory and stress‐induced visceral hypersensitivity

“…To determine whether persistent low-grade inflammation contrib- and Ccl2) was upregulated and muscle thickness was increased in ephrin-B2 cKO compared with WT mice ( Figure 3A,C), suggesting that ephrin-B2 from Na v 1.8 neurons may be involved in immune homeostasis. Additionally, although MS-induced stress alters the fecal pellet output after each WAS session 42,48 as well as the escape behavior 49 compared to no handling, the stress response was similar between WT and cKO mice ( Figure S2G,H).…”

Expression of Neurotrophic Factors, Tight Junction Proteins, and Cytokines According to the Irritable Bowel Syndrome Subtype and Sex

“…In one animal study, colonic mucosal expression levels of IFN-γ, TNF-α, IL-6, and IL-17 were higher in female IBS model rats, suggesting sex differences in cytokine expression. 8 However, in another animal study, only IL-1β expression level was increased in the colonic mucosa of female IBS rats. 7 It is important to note that research on the aforementioned aspects is still lacking.…”

“…[4][5][6] For instance, IBS-constipation (IBS-C) is frequent in females whereas IBS-diarrhea (IBS-D) is predominant in males. [4][5][6] Despite there are a few reports regarding sex and gender difference of IBS in animal studies, 7,8 causes of vulnerability of females to IBS remain unclear. 5,9 So far, most IBS studies have focused on IBS-D or post-infectious IBS (PI-IBS) that develops into IBS-D or on mixed type IBS (IBS-M).…”