Prevalence of methanogens and associated factors in patients with irritable bowel syndrome and healthy controls in a Southeastern Mexican population.

INTRODUCTION: Methane (CH4) is an inert gas produced by colonic anaerobes and has been associated with different intestinal diseases, including irritable bowel syndrome (IBS). According to geographic region, the prevalence of methanogens varies, being higher in Africa (80%) and lower in the United States (35-40%). In Mexico, the prevalence of methanogens is unknown. AIM: To evaluate the prevalence of CH4 producers and associated factors in a group of patients with IBS and controls in a Mexican population. MATERIALS AND METHODS: A baseline fasting measurement of alveolar H2 and CH4 gas was carried out, by gas chromatography (stationary phase), in consecutive patients diagnosed with IBS and a control group. Subjects with baseline levels of H2 of 0 ppm and CH4 ≥ 5 ppm were classified as methanogenic. RESULTS: A total of 132 controls (53.8% women) and 67 patients with IBS (76% women) were included. The overall prevalence (n = 199) of methanogenic subjects was 38% (n = 76) (95% CI: 0.31-0.45) and they had a greater prevalence of overweight/obesity (56.5 vs 39.8%, P = .028). The prevalence of methanogens in the healthy controls was 41.6% (95% CI: 0.33-0.49), whereas, in the patients with IBS, it was 31.4% (n = 21, 71% IBS-C and 29% IBS-M). CONCLUSIONS: The prevalence of methanogens in our study on a Mexican population was comparable to that reported in other populations and was associated with overweight/obesity. One-third of the patients with IBS presented with methanogens. Said microorganisms were particularlyassociated with the constipation-predominant IBS subtype.

Metabolic effects in patients with celiac disease, patients with nonceliac gluten sensitivity, and asymptomatic controls, after six months of a gluten-free diet. / Efectos de una dieta libre de gluten (DLG) durante 6 meses sobre el metabolismo en pacientes con enfermedad celíaca, sensibilidad al gluten no celíaca y controles asintomáticos.

INTRODUCTION AND OBJECTIVES: It is essential for patients with celiac disease (CD) to be on a gluten-free diet (GFD) but said diet has also been reported to increase the risk for metabolic syndrome. There is no evidence on the metabolic effects of a GFD in patients with nonceliac gluten sensitivity (NCGS) or in asymptomatic subjects. Therefore, the aim of the present study was to evaluate the metabolic effects of a GFD over a 6-month period in patients with CD, patients with NCGS, and in asymptomatic controls (ACs). MATERIALS AND METHODS: A prospective study was conducted that evaluated metabolic syndrome and its components of obesity, high blood pressure, hepatic steatosis, and hyperglycemia at the baseline and at 6 months. RESULTS: A total of 66 subjects (22 CD, 22 NCGS, and 22 AC) were included in the study. At the baseline, 10% of the patients with CD presented with obesity, high blood pressure, hepatic steatosis, and metabolic syndrome. After 6 months, obesity and metabolic syndrome increased by 20% (p=0.125). In the patients with NCGS, obesity increased by 5% after the GFD and 20% of those patients presented with de novo hepatic steatosis. The prevalence of obesity decreased by 10% in the controls after the GFD (30 vs 20%, p=0.5) and none of the other components of metabolic syndrome were affected. CONCLUSIONS: The metabolic benefits and risks of a GFD should be considered when prescribing said diet in the different populations that opt for that type of intervention.

Trastornos relacionados con el gluten: panorama actual / Gluten-related disorders: Current state

Resumen: El trigo representa uno de los cereales que más se producen y consumen en todo el mundo debido a su sencillez para ser cultivado en diversas condiciones climáticas, su valor nutricional y sus características organolépticas. El trigo, al igual que la cebada y el centeno, contienen gluten, molécula que potencialmente puede resultar tóxica para algunos individuos. Los trastornos relacionados con el gluten representan un reto diagnóstico-terapéutico en la actualidad porque incluyen enfermedades que pueden tener complicaciones y efectos nocivos para la salud, como la enfermedad celiaca, hasta situaciones puramente sintomáticas, como la sensibilidad al gluten no celiaca. Se necesita una alta sospecha clínica y el conocimiento e interpretación de las pruebas diagnósticas (serología, biopsias y pruebas genéticas) para tener un abordaje apropiado. En México se estima que 1% de la población padece enfermedad celiaca, 0.7% alergia al trigo y la sensibilidad al gluten no celiaca varía de 1 hasta 25% en poblaciones especiales (intestino irritable, dispepsia). En la actualidad los pacientes con enfermedad celiaca comprobada deben someterse a una estricta dieta sin gluten por el riesgo potencial de complicaciones. Asimismo, si bien se recomienda este tipo de dieta a los pacientes con sensibilidad al gluten no celiaca, la falta de apego sólo condicionará recaídas sintomáticas. Por otra parte, aunque existe gran disponibilidad de dietas que excluyen el gluten, éstas no se recomiendan para la población general o en casos en los que no esté establecido propiamente el diagnóstico de algunos de los trastornos relacionados con el gluten.

Abstract: Wheat is one of the most produced and consumed cereals worldwide because of its simplicity to be cultivated in different climatic conditions, its nutritional value and its organoleptic characteristics. Wheat, as barley and rye, contains a molecule which can potentially be toxic to some individuals, the gluten. Today gluten-related disorders represent a diagnostic and therapeutic challenge as they include diseases that can have complications and deleterious health effects such as celiac disease, to purely symptomatic situations such as non-celiac gluten sensitivity (NGCS). A high clinical suspicion, as well as knowledge in the interpretation of diagnostic tests (serology, biopsy and genetic testing) are required to have an appropriate approach. In Mexico it is estimated that 1% of the population suffers celiac disease, 0.7% wheat allergy and NGCS can vary from 1% to 25% in special populations (irritable bowel syndrome, dyspepsia). At present proven celiac disease patients must undergo a strict gluten-free diet for the potential risk of complications. On the other hand in patients with NGCS, although this type of diet is recommended, lack of adherence will only lead to symptomatic relapse. Moreover, although there is a great availability of gluten free diets and products, these are not recommended for the general population or in cases in who the diagnosis of some of the gluten-related disorders is not properly established.