Methane intestinal production and poor metabolic control in type I diabetes complicated by autonomic neuropathy.

AIM: At the state of art it's unknown the correlation between diabetes and lower gastrointestinal disorders. Some studies show a significantly higher prevalence of small intestinal bacterial overgrowth in patients with type I diabetes in particular complicated by autonomic neuropathy. No data exists about gastrointestinal methane production in patients with diabetes and autonomic diabetic neuropathy. The aim of this paper was to evaluate the correlation of small intestinal bacterial overgrowth and gastrointestinal methane production with metabolic control and daily insulin requirements in patients with type 1 diabetes and. autonomic diabetic neuropathy. METHODS: Thirty subjects with type 1 diabetes and autonomic diabetic neuropathy were underwent hydrogen and methane lactulose breath test (LBT) to evaluate the presence of small intestinal bacterial overgrowth (double peak of hydrogen) and methane production. The metabolic control was evaluated through the glycated hemoglobin and the daily insulin requirement (calculated as ratio between total insulin units in a day and body weight). Methane producers were treated with metronidazole (500 mg bid for 10 days) and perform a LBT 8 weeks after the end of therapy RESULTS: Eight over thirty patients (26.6%) met the diagnostic criteria for small intestinal bacterial overgrowth. 11/30 patients (36%) were methane-producers (mean baseline value 16.37 ± 13.01 ppm; mean peak 26.62 ± 11.41 ppm); interestingly this subset of patients showed a worse glycemic control (mean HbA1c 8.16 ± 0.9% vs. 7.49 ± 0.8%, P<0.05). After metronidazole therapy 7/11 (63.3%) reduced CH4 production and they showed a mean HbA1c significantly lower than corresponding value before antibiotic therapy (7.63 ± 0.7% vs. 8.25 ± 0.8%). CONCLUSION: Our study showed for the first time a possible role of CH4 production in metabolic control. In particular, the most interesting data is that an increased values of HbA1c seems to be related to a gut CH4 production as confirmed by its significant improvement after eradication therapy. We are not yet able to determine whether poor glycemic control is the cause or the consequence of the selection of methanogenic flora.

Levothyroxine absorption in health and disease, and new therapeutic perspectives.

Levothyroxine therapy is used in case of deficiency of the thyroid hormones in the human organism. Many conditions, either physiological or paraphysiological or clearly pathological, can alter the levothyroxine absorption in the human body. Levothyroxine absorption can indeed be impaired by age, patient's compliance, fasting, the intake of certain foods (such as dietary fibers, grapes, soybeans, papaya and coffee) or by some drugs (such as proton-pump inhibitors, antacids, sucralfate, et cetera). Additionally, many gastrointestinal diseases, such as the conditions that disrupt the integrity of the intestinal barrier and the diseases that impair gastric acidity, may alter the bioavailability of levothyroxine. Since the enormous, widespread diffusion of thyroid diseases, a large number of patients have to face such issues. Therefore, the development of new levothyroxine oral formulations, other than solid tablets, may represent an interesting therapeutic approach, at the same time simple and effective, to face this problem. Recently, two different levothyroxine formulations have been proposed: the liquid formulation and the softgel formulation. Such formulations represent an innovative, effective and cheap therapeutic approach to hypothyroid patient with problems of impaired absorption of levothyroxine.

Nickel free-diet enhances the Helicobacter pylori eradication rate: a pilot study.

BACKGROUND: The Helicobacter pylori eradication rate with standard triple therapy is very low. H. pylori is known to require the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive at the low pH environment in the stomach. AIM: To compare the H. pylori eradication rate of a nickel free-diet associated with standard triple therapy and standard triple therapy alone as the first-line regimen. METHODS: Fifty-two sex- and age-matched patients at the first diagnosis of H. pylori infection were randomized 1:1 into two different therapeutic schemes: (1) standard LCA (26 patients): lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid for 7 days with a common diet; (2) standard LCA plus a nickel free-diet (NFD-LCA) (26 patients). Patients followed 30 days of a nickel-free diet plus a week of lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid starting from day 15 of the diet. RESULTS: All patients completed the study. A significantly higher eradication rate was observed in the NFD-LCA group (22/26) versus LCA group (12/26) (p < 0.01). Only a few patients (9 of 52) reported the occurrence of mild therapy-related side effects, without any significant differences between the two groups. CONCLUSIONS: The addition of a nickel-free diet to standard triple therapy significantly increases the H. pylori eradication rate. The reduction of H. pylori urease activity due to the nickel-free diet could expose the bacterium to gastric acid and increase H. pylori's susceptibility to amoxicillin. Further studies are necessary to confirm this preliminary result.

Something more to say about calcium homeostasis: the role of vitamin K2 in vascular calcification and osteoporosis.

BACKGROUND: Vascular calcification and osteoporosis share similar etiopathogenetic mechanisms. Vitamin K2 deficiency could be responsible of the so called "calcium paradox", that is the lack of calcium in the bone and its storage in the vessel wall. These events may have clinically relevant consequences, such as cardiovascular accidents, and bone fractures. AIM: To review the biological function of vitamin K2 metabolism, the main factors related to its deficiency and the consequent clinical significance. DISCUSSION: Vitamin K2 is essential for the function of several proteins, involved in the maintenance of the normal structure of arterial wall, osteoarticular system, teeth, and for the regulation of cell growth. It has been demonstrated to have a pivotal role in the inhibition of vascular foci of calcification, and in the regulation of calcium deposition in the bone. Vitamin K2 deficiency is often subclinic in a large part of healthy population. This deficiency is related to the interaction of various factors, such as the reduced dietary intake, the alteration of intestinal absorption or production, with a possible role of intestinal microbiota and the increased consumption at the vessel wall. CONCLUSIONS: Vitamin K2 deficiency has recently been recognized as a protagonist in the development of vascular calcification and osteoporosis. Data reported so far are promising and, dietary supplementation seems a useful tool to contrast these diseases. However, large studies or solid clinical correlations regarding vitamin K2 deficiency and its pathologic consequences are needed to confirm these preliminary experiences.

13C-Urea breath test for the diagnosis of Helicobacter pylori infection.

Helicobacter pylori (H. pylori) is a Gram-negative bacterium able to colonize the gastric mucosa as well as gastric metaplastic areas of the duodenum, producing inflammation. The clinical outcome depends on sophisticated interactions between bacterial factors, such as the expression of determinants of virulence and pathogenicity, and host characteristics. The severity of inflammation, may then vary among different subjects, leading to the occurrence of different gastroduodenal diseases, ranging from chronic gastritis to gastric cancer and MALT-lymphoma, to some defined extragastric manifestations. Many diagnostic tests are available for the detection of H. pylori infection including noninvasive methods, such as serology, (13)C-urea breath test (UBT), and fecal antigen tests and invasive techniques, including a combined use of endoscopic biopsy-based methods, such as rapid urease testing, histology, culture, and molecular methods. UBT is a highly sensitive and specific and allows to diagnose the presence or absence of infection of H. pylori, through the oral administration of a solution containing urea labelled with the non-radioactive natural carbon 13. This review article analyzes microbiological and clinical features of H. pylori as well as the different diagnostic tests able to detect this bacterium with a special focus on UBT.

Tricks for interpreting and making a good report on hydrogen and 13C breath tests.

Breath tests (BT) represent a valid and non-invasive diagnostic tool in many gastroenterological disorders. Their wide diffusion is due to the low cost, simplicity and reproducibility and their common indications include diagnosis of carbohydrate malabsorption, Helicobacter pylori infection, small bowel bacterial overgrowth, gastric emptying time and orocaecal transit time. The review deals with key points on methodology, which would influence the correct interpretation of the test and on a correct report. While a clear guideline is available for lactose and glucose breath tests, no gold standard is available for Sorbitol, Fructose or other H2 BTs. Orocaecal transit time (OCTT) defined as time between assumption of 10 g lactulose and a peak > 10 ppm over the baseline value, is a well-defined breath test. The possible value of lactulose as a diagnostic test for the diagnosis of small bowel bacterial overgrowth is still under debate. Among (13)C breath test, the best and well characterized is represented by the urea breath test. Well-defined protocols are available also for other (13)C tests, although a reimbursement for these tests is still not available. Critical points in breath testing include the patient preparation for test, type of substrate utilized, reading machines, time between when the test is performed and when the test is processed. Another crucial point involves clinical conclusions coming from each test. For example, even if lactulose could be utilized for diagnosing small bowel bacterial overgrowth, this indication should be only secondary to orocaecal transit time, and added into notes, as clinical guidelines are still uncertain.