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Background: Lactase activity declines with age in rats, but it is not clear whether this model is also shared by humans. Few studies have evaluated lactose intolerance and malabsorption in the elderly and no definite conclusions can be drawn. The aim of our study was therefore to verify the impact of age on lactose intolerance and malabsorption. Methods: Eighty-four healthy subjects took part in the study. Thirty-three were < 65 years, 17 were between 65 and 74 years and 34 were > 74 years. All the subjects underwent a preliminary evaluation of intestinal gas production capacity and oro-cecal transit time by H[sub 2]/CH[sub 4] breath test after lactulose. After a 3-day period, an H[sub 2]/CH[sub 4] breath test after lactose was performed. The occurrence of intolerance symptoms during the test and in the 24 h after the test was recorded. Results: Breath H[sub 2] and CH[sub 4] excretion parameters at fasting and after lactulose did not differ between the three groups. Cumulative breath H[sub 2] excretion after lactose was higher in subjects > 74 years than in subjects < 65 years and in subjects aged 65-74 years, while no difference was found between the latter two groups. In subjects > 74 years, the prevalence of lactose malabsorption was higher than in the other two groups, while no significant difference was observed between subjects < 65 years and subjects aged 65-74 years. Within the malabsorber subjects, the prevalence of lactose intolerance was higher in subjects < 65 years than in those aged 65-74 years and in those aged > 74 years. No significant difference was found between the latter two groups. No difference was found between the three groups in terms of daily calcium intake and a significant negative correlation between symptom score and daily calcium intake was only found in the group of subjects aged < 65 years. Conclusions: As age increases, the prevalence of lactose malabsorption shows an increase while the prevalence of intolerance symptoms among malabsorbers shows a decrease. Accordingly, daily calcium intake was similar among the adults and elderly studied. [ABSTRACT FROM AUTHOR]

Small intestine bacterial overgrowth is a malabsorption syndrome and, therefore, it may contribute to the occurrence of metabolic bone disease. However, studies that evaluate the magnitude of this problem and the potential underlying mechanisms are still needed. Fourteen patients with bacterial overgrowth and 22 comparable healthy volunteers took part in this study. All patients were affected by conditions known to predispose to bacterial overgrowth. Diagnosis was based on the following criteria: increased breath hydrogen levels in the fasting state and/or increased breath hydrogen excretion after the ingestion of 50 g of glucose solution, improvement after a 10-day course of antibiotic therapy of severity of symptoms and of H2 excretion parameters. Measurement of bone mineral density by dual-energy x-ray absorptiometry at lumbar spine and femoral level and evaluation of nutritional status were performed. Physical activity, sunlight exposure, and cigarette smoking were also evaluated. Patients showed lumbar and femoral bone mineral density values significantly lower than control group; also the prevalence of bone loss at both lumbar and femoral levels was higher in patient group than in healthy volunteers. Body mass index was significantly lower in patients than in healthy volunteers. Lumbar and femoral bone mineral density were significantly correlated and both correlated with body mass index and with duration of symptoms. No correlation between BMD values and physical activity, sunlight exposure, and cigarette smoking was evident. Our results show that small intestine bacterial overgrowth is an important cofactor in the development of metabolic bone disease. The severity of bone loss is related to poor nutritional status and duration of malabsorption symptoms. [ABSTRACT FROM AUTHOR]

Background: Simethicone, activated charcoal and antimicrobial drugs have been used to treat gas-related symptoms with conflicting results. Aim: To study the relationship between gaseous symptoms and colonic gas production and to test the efficacy of rifaximin, a new non-absorbable antimicrobial agent, on these symptoms. Methods: Intestinal gas production was measured by hydrogen (H2) and methane (CH4) breath testing after lactulose in 21 healthy volunteers and 34 functional patients. Only the 34 functional patients took part in a double-blind, double-dummy controlled trial, receiving, at random, rifaximin (400 mg b.d per 7 days), or activated charcoal (400 mg b.d per 7 days). The following parameters were evaluated at the start of the study and 1 and 10 days after therapy: bloating, abdominal pain, number of flatus episodes, abdominal girth, and cumulative breath H2 excretion. Results: Hydrogen excretion was greater in functional patients than in healthy volunteers. Rifaximin, but not activated charcoal, led to a significant reduction in H2 excretion and overall severity of symptoms. In particular, in patients treated with rifaximin, a significant reduction in the mean number of flatus episodes and of mean abdominal girth was evident. Conclusions: In patients with gas-related symptoms the colonic production of H2 is increased. Rifaximin significantly reduces this production and the excessive number of flatus episodes. [ABSTRACT FROM AUTHOR]