Concordant pattern of the HPA axis response to visceral stimulation and CRH administration

Neural circuits regulating visceral pain

Visceral hypersensitivity, a common clinical manifestation of irritable bowel syndrome, may contribute to the development of chronic visceral pain, which is a major challenge for both patients and health providers. Neural circuits in the brain encode, store, and transfer pain information across brain regions. In this review, we focus on the anterior cingulate cortex and paraventricular nucleus of the hypothalamus to highlight the progress in identifying the neural circuits involved in visceral pain. We also discuss several neural circuit mechanisms and emphasize the importance of cross-species, multiangle approaches and the identification of specific neurons in determining the neural circuits that control visceral pain.

Impact of mindfulness tendency and physical activity on brain-gut interactions

BACKGROUND

Irritable bowel syndrome (IBS) is a disorder of brain-gut interactions characterized by abdominal pain and bowel dysfunction. Exercise and mindfulness have been reported to be effective on IBS, but there has been no study of their interaction. In this study, we hypothesized that exercise and mindfulness interactively affect the severity of IBS symptoms.

METHODS

Subjects were 703 adolescents with 590 women and 113 men. Their IBS status was evaluated with Rome III Diagnostic Questionnaire and IBS Severity Index (IBS-SI). They also fulfilled past exercise experience, athletic performance and exercise enthusiasm, International Physical Activity Questionnaire (IPAQ), Mindful Attention Awareness Scale (MAAS), Kessler 6 Scale (K6), and Perceived Stress Scale (PSS). Statistical analysis was performed using SPSS v25.

RESULTS

In this population, 184 (158 women and 26 men, 14.1%) subjects had Rome III IBS symptoms. IBS subjects scored significantly less in exercise enthusiasm at high school (p = 0.017) and MAAS (p < 0.001) and significantly more K6 (p < 0.001) and PSS (p < 0.001) than non-IBS. The two-way ANOVA on IBS-SI showed a significant main effect of MAAS (p < 0.001) and interaction between MAAS and IPAQ (p = 0.008).

CONCLUSION

It is suggested that mindfulness per se decreases IBS severity, but that mindfulness and physical activity interactively affect the severity. Further studies on how to design interventional trials for IBS patients with mindfulness and physical exercise are warranted.

Estrogen receptor β deficiency impairs gut microbiota: a possible mechanism of IBD-induced anxiety-like behavior

BACKGROUND

Although the lack of estrogen receptor β (ERβ) is a risk factor for the development of inflammatory bowel disease (IBD) and psychiatric disorders, the underlying cellular and molecular mechanisms are not fully understood. Herein, we revealed the role of gut microbiota in the development of IBD and related anxiety-like behavior in ERβ-deficient mice.

RESULTS

In response to dextran sodium sulfate (DSS) insult, the ERβ knockout mice displayed significant shift in α and β diversity in the fecal microbiota composition and demonstrated worsening of colitis and anxiety-like behaviors. In addition, DSS-induced colitis also induced hypothalamic-pituitary-adrenal (HPA) axis hyperactivity in ERβ-deficient mice, which was associated with colitis and anxiety-like behaviors. In addition, RNA sequencing data suggested that ErbB4 might be the target of ERβ that is involved in regulating the HPA axis hyperactivity caused by DSS insult. Gut microbiota remodeling by co-housing showed that both the colitis and anxiety-like behaviors were aggravated in co-housed wild-type mice compared to single-housed wild-type mice. These findings suggest that gut microbiota play a critical role in mediating colitis disease activity and anxiety-like behaviors via aberrant neural processing within the gut-brain axis.

CONCLUSIONS

ERβ has the potential to inhibit colitis development and anxiety-like behaviors via remodeling of the gut microbiota, which suggests that ERβ is a promising therapeutic target for the treatment of IBD and related anxiety-like behaviors. Video Abstract.