The vagus nerve (VN) is a link between the brain and the gut. The VN is a mixed nerve with anti-inflammatory properties through the activation of the hypothalamic-pituitary-adrenal axis by its afferents and by activating the cholinergic anti-inflammatory pathway through its efferents. We have previously shown that VN stimulation (VNS) improves colitis in rats and that the vagal tone is blunted in Crohn's disease (CD) patients. We thus performed a pilot study of chronic VNS in patients with active CD. Seven patients under VNS were followed up for 6 months with a primary endpoint to induce clinical remission and a secondary endpoint to induce biological (CRP and/or fecal calprotectin) and endoscopic remission and to restore vagal tone (heart rate variability). Vagus nerve stimulation was feasible and well-tolerated in all patients. Among the seven patients, two were removed from the study at 3 months for clinical worsening and five evolved toward clinical, biological, and endoscopic remission with a restored vagal tone. These results provide the first evidence that VNS is feasible and appears as an effective tool in the treatment of active CD.

Psychological factors and the autonomic nervous system (ANS) are implicated in the pathogenesis of inflammatory bowel diseases (IBD) and irritable bowel syndrome (IBS). This study aimed to assess, firstly the way IBS and IBD patients cope with their pathology according to their affective adjustment and secondly the possible links between these affective adjustments and ANS reactivity. Patients with Crohn's disease (CD; n=26), ulcerative colitis (UC; n=22), or IBS (n=27) were recruited and compared to 21 healthy subjects based on psychological variables (trait- and state anxiety, depressive symptomatology, negative mood, perceived stress, coping, health locus of control) and sympatho-vagal balance through heart-rate variability monitored at rest. A principal component analysis, performed on all affective variables, isolated a leading factor labelled as "affective adjustment". In each disease, patients were distributed into positive and negative affective adjustment. In all the diseases, a positive affect was associated with problem-focused coping, and a negative affect with emotion-focused coping and external health locus of control. Results show that the sympatho-vagal balance varied according to the disease. In CD presenting positive affectivity, an adapted high sympathetic activity was observed. In UC, a parasympathetic blunt was observed in the presence of negative affectivity and an equilibrated sympatho-vagal balance in the presence of positive affectivity. In contrast, in IBS, an important dysautonomia (with high sympathetic and low parasympathetic tone) was constantly observed whatever the affective adjustment. In conclusion, this study suggests that the equilibrium of the ANS is differentially adapted according to the disease. This equilibrium is conjugated with positive affective and cognitive adjustment in IBD (CD and UC) but not in IBS.

Crohn’s disease (CD) and irritable bowel syndrome (IBS) involve brain-gut dysfunctions where vagus nerve is an important component. The aim of this work was to study the association between vagal tone and markers of stress and inflammation in patients with CD or IBS compared to healthy subjects (controls). The study was performed in 73 subjects (26 controls, 21 CD in remission and 26 IBS patients). The day prior to the experiment, salivary cortisol was measured at 8∶00 AM and 10∶00 PM. The day of the experiment, subjects completed questionnaires for anxiety (STAI) and depressive symptoms (CES-D). After 30 min of rest, ECG was recorded for heart rate variability (HRV) analysis. Plasma cortisol, epinephrine, norepinephrine, TNF-alpha and IL-6 were measured in blood samples taken at the end of ECG recording. Compared with controls, CD and IBS patients had higher scores of state-anxiety and depressive symptomatology. A subgroup classification based on HRV-normalized high frequency band (HFnu) as a marker of vagal tone, showed that control subjects with high vagal tone had significantly lower evening salivary cortisol levels than subjects with low vagal tone. Such an effect was not observed in CD and IBS patients. Moreover, an inverse association (r = −0.48; p<0.05) was observed between the vagal tone and TNF-alpha level in CD patients exclusively. In contrast, in IBS patients, vagal tone was inversely correlated with plasma epinephrine (r = −0.39; p<0.05). No relationship was observed between vagal tone and IL-6, norepinephrine or negative affects (anxiety and depressive symptomatology) in any group. In conclusion, these data argue for an imbalance between the hypothalamus-pituitary-adrenal axis and the vagal tone in CD and IBS patients. Furthermore, they highlight the specific homeostatic link between vagal tone and TNF-alpha in CD and epinephrine in IBS and argue for the relevance of vagus nerve reinforcement interventions in those diseases.

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The authors studied the prevalence of heavy drinking among students in 21 developed and developing countries using an anonymous survey of 7,846 male and 9,892 female students aged 17 to 30 years. There were wide variations in the prevalence of drinking among countries, and the highest rates of heavy drinking (defined as 5 or more drinks for men and 4 or more drinks for women on at least 1 occasion over the past 2 weeks) were reported in Belgium, Colombia, Ireland, and Poland (men), and Ireland and England (women). Heavy drinking was associated with living away from home, having a wealthier family background, and having well-educated parents. Beliefs about the dangers to health of excessive consumption were negatively related to heavy drinking. Heavy drinking is a concern among students in several countries and is associated with greater affluence. Challenging beliefs concerning health risks is a crucial aspect of prevention in this population.