Dietary fiber and the microbiota: A narrative review by a group of experts from the Asociación Mexicana de Gastroenterología.

Dietary fiber intake is one of the most influential and efficacious strategies for modulating the gut microbiota. Said fiber can be digested by the microbiota itself, producing numerous metabolites, which include the short-chain fatty acids (SCFAs). SCFAs have local and systemic functions that impact the composition and function of the gut microbiota, and consequently, human health. The aim of the present narrative review was to provide a document that serves as a frame of reference for a clear understanding of dietary fiber and its direct and indirect effects on health. The direct benefits of dietary fiber intake can be dependent on or independent of the gut microbiota. The use of dietary fiber by the gut microbiota involves several factors, including the fiber's physiochemical characteristics. Dietary fiber type influences the gut microbiota because not all bacterial species have the same capacity to produce the enzymes needed for its degradation. A low-fiber diet can affect the balance of the SCFAs produced. Dietary fiber indirectly benefits cardiometabolic health, digestive health, certain functional gastrointestinal disorders, and different diseases.

Technical position on milk and its derivatives in adult health and disease from the Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Gerontología y Geriatría. / Posición técnica sobre la leche y derivados lácteos en la salud y en la enfermedad del adulto de la Asociación Mexicana de Gastroenterología y la Asociación Mexicana de Gerontología y Geriatría.

Milk is a liquid food that possesses an important quantity of highly bioavailable macronutrients. In addition, it is readily accessible, as well as relatively inexpensive. Given that the knowledge of physicians about nutrition and food composition is deficient, in general, many of the dietary interventions recommended in diverse clinical settings lack a scientific basis. The aim of the present review was to produce a technical opinion that serves as a frame of reference to best sustain recommendations for consuming milk and dairy products as daily nutrition in the adult and older adult. The effects of milk and dairy products during the pediatric stage are not addressed in the present work. The Asociación Mexicana de Gastroenterología and the Asociación Mexicana de Gerontología y Geriatría jointly discussed and analyzed topics dealing with the legal designation of milk, the classification and nutritional profile of cow's milk, its nutritional characteristics, its consumption in the adult, intolerance to cow's milk, and associations of milk consumption with digestive tract alterations and other conditions. Finally, certain aspects of milk consumption in the older adult and its relation to overall health are briefly discussed.

Clinical guidelines on the diagnosis and treatment of celiac disease in Mexico. / Guía clínica para diagnóstico y tratamiento de la enfermedad celíaca en México.

Celiac disease, celiac sprue, or gluten-sensitive enteropathy, is a generalized autoimmune disease characterized by chronic inflammation and atrophy of the small bowel mucosa. It is caused by dietary exposure to gluten and affects genetically predisposed individuals. In Mexico, at least 800,000 are estimated to possibly have the disease, prompting the Asociación Mexicana de Gastroenterología to summon a multidisciplinary group of experts to develop the "Clinical guidelines on the diagnosis and treatment of celiac disease in Mexico" and establish recommendations for the medical community, its patients, and the general population. The participating medical professionals were divided into three working groups and were given the selected bibliographic material by the coordinators (ART, LUD, JMRT), who proposed the statements that were discussed and voted upon in three sessions: two voting rounds were carried out electronically and one at a face-to-face meeting. Thirty-nine statements were accepted, and once approved, were developed and revised by the coordinators, and their final version was approved by all the participants. It was emphasized in the document that epidemiology and risk factors associated with celiac disease (first-degree relatives, autoimmune diseases, high-risk populations) in Mexico are similar to those described in other parts of the world. Standards for diagnosing the disease and its appropriate treatment in the Mexican patient were established. The guidelines also highlighted the fact that a strict gluten-free diet is essential only in persons with confirmed celiac disease, and that the role of gluten is still a subject of debate in relation to nonceliac, gluten-sensitive patients.

[Deficient lactose digestion and intolerance in a group of patients with chronic nonspecific ulcerative colitis: a controlled, double-blind, cross-over clinical trial]. / Digestión deficiente e intolerancia a lactosa en un grupo de enfermos con colitis ulcerativa crónica inespecífica: Ensayo clínico controlado, cruzado y doblemente a ciegas.

INTRODUCTION: Despite the fact that the frequency of hypolactasia and lactose intolerance is similar in both chronic idiopathic ulcerative colitis patients and the general population, the elimination of dairy products from the patient's diet is a habitual recommendation. Hypolactasia is common in Mexico, but its relation to chronic idiopathic ulcerative colitis has not been established. AIMS: To evaluate lactose digestion and lactose intolerance in persons with chronic idiopathic ulcerative colitis. MATERIAL AND METHODS: Thirty-nine patients with confirmed chronic idiopathic ulcerative colitis diagnosis were included in the study (mean: 31 years, range: 15 to 38). Twenty-two patients presented with rectosigmoid involvement and the remaining patients with pancolitis. No patient showed inflammatory activity according to the Truelove-Witts criteria and all consumed dairy products before diagnosis. A prospective, controlled, double-blind, cross-over study was designed. Patients randomly received 12.5 g of lactose or maltose in 250 cc water- each test 72 hours apart - and ydrogen was measured in exhaled air before disaccharide ingestion and then every 30 minutes for 3 hours. Digestion was considered deficient when there was an increase in hydrogen of at least 20 ppm. Symptom intensities were evaluated by Visual Analog Scales before, during, and after the hydrogen test. Differences between the groups were contrasted with the Mann-Whitney U and the Wilcoxon tests. RESULTS: Eighteen patients (46%) presented with deficient lactose digestion. No significant differences were found in the symptoms, extension, or progression of chronic idiopathic ulcerative colitis between patients that could digest and those that could not digest lactose. No patient had symptom exacerbation with the disaccharides used. CONCLUSIONS: Lactose digestion deficiency frequency is similar in subjects with chronic idiopathic ulcerative colitis and in healthy individuals in Mexico. We do not know whether higher doses could have some effect, but symptoms in patients with inactive chronic idiopathic ulcerative colitis were not modified using 12.5 g of lactose/day.