Good adherence to mediterranean diet can prevent gastrointestinal symptoms: A survey from Southern Italy

AIM

To evaluate how different levels of adherence to a mediterranean diet (MD) correlate with the onset of functional gastrointestinal disorders.

METHODS

As many as 1134 subjects (598 M and 536 F; age range 17-83 years) were prospectively investigated in relation to their dietary habits and the presence of functional gastrointestinal symptoms. Patients with relevant chronic organic disease were excluded from the study. The Mediterranean Diet Quality index for children and adolescents (KIDMED) and the Short Mediterranean Diet Questionnaire were administered. All subjects were grouped into five categories according to their ages: 17-24 years; 25-34; 35-49; 50-64; above 64.

RESULTS

On the basis of the Rome III criteria, our population consisted of 719 (63.4%) individuals who did not meet the criteria for any functional disorder and were classified as controls (CNT), 172 (13.3%) patients meeting criteria for prevalent irritable bowel syndrome (IBS), and 243 (23.3%) meeting criteria for prevalent functional dyspepsia (FD). A significantly lower adherence score in IBS (0.57 ± 0.23, P < 0.001) and FD (0.56 ± 0.24, P < 0.05) was found compared to CNT (0.62 ± 0.21). Females with FD and IBS exhibited significantly lower adherence scores (respectively 0.58 ± 0.24, P < 0.05 and 0.56 ± 0.22, P < 0.05) whereas males were significantly lower only for FD (0.53 ± 0.25, P < 0.05). Age cluster analyses showed a significantly lower score in the 17-24 years and 25-34 year categories for FD (17-24 years: 0.44 ± 0.21, P < 0.001; 25-34 years: 0.48 ± 0.22, P < 0.05) and IBS (17-24 years: 0.45 ± 0.20, P < 0.05; 24-34 years: 0.44 ± 0.21, P < 0.001) compared to CNT (17-24 years: 0.56 ± 0.21; 25-34 years: 0.69 ± 0.20).

CONCLUSION

Low adherence to MD may trigger functional gastrointestinal symptoms, mainly in younger subjects. Moreover, with increasing age, patients tend to adopt dietary regimens closer to MD.

Bloating and functional gastro-intestinal disorders: Where are we and where are we going?

Bloating is one of the most common and bothersome symptoms complained by a large proportion of patients. This symptom has been described with various definitions, such as sensation of a distended abdomen or an abdominal tension or even excessive gas in the abdomen, although bloating should probably be defined as the feeling (e.g. a subjective sensation) of increased pressure within the abdomen. It is usually associated with functional gastrointestinal disorders, like irritable bowel syndrome, but when bloating is not part of another functional bowel or gastrointestinal disorder it is included as an independent entity in Rome III criteria named functional bloating. In terms of diagnosis, major difficulties are due to the lack of measurable parameters to assess and grade this symptom. In addition, it is still unclear to what extent the individual patient complaint of subjective bloating correlates with the objective evidence of abdominal distension. In fact, despite its clinical, social and economic relevance, bloating lacks a clear pathophysiology explanation, and an effective management endorsement, turning this common symptom into a true challenge for both patients and clinicians. Different theories on bloating etiology call into questions an increased luminal contents (gas, stools, liquid or fat) and/or an impaired abdominal empting and/or an altered intra-abdominal volume displacement (abdomino-phrenic theory) and/or an increased perception of intestinal stimuli with a subsequent use of empirical treatments (diet modifications, antibiotics and/or probiotics, prokinetic drugs, antispasmodics, gas reducing agents and tricyclic antidepressants). In this review, our aim was to review the latest knowledge on bloating physiopathology and therapeutic options trying to shed lights on those processes where a clinician could intervene to modify disease course.

Functional brain imaging of gastrointestinal sensation in health and disease

It has since long been known, from everyday experience as well as from animal and human studies, that psychological processes-both affective and cognitive-exert an influence on gastrointestinal sensorimotor function. More specifically, a link between psychological factors and visceral hypersensitivity has been suggested, mainly based on research in functional gastrointestinal disorder patients. However, until recently, the exact nature of this putative relationship remained unclear, mainly due to a lack of non-invasive methods to study the (neurobiological) mechanisms underlying this relationship in non-sleeping humans. As functional brain imaging, introduced in visceral sensory neuroscience some 10 years ago, does provide a method for in vivo study of brain-gut interactions, insight into the neurobiological mechanisms underlying visceral sensation in general and the influence of psychological factors more particularly, has rapidly grown. In this article, an overview of brain imaging evidence on gastrointestinal sensation will be given, with special emphasis on the brain mechanisms underlying the interaction between affective & cognitive processes and visceral sensation. First, the reciprocal neural pathways between the brain and the gut (brain-gut axis) will be briefly outlined, including brain imaging evidence in healthy volunteers. Second, functional brain imaging studies assessing the influence of psychological factors on brain processing of visceral sensation in healthy humans will be discussed in more detail. Finally, brain imaging work investigating differences in brain responses to visceral distension between healthy volunteers and functional gastrointestinal disorder patients will be highlighted.