Corresponding author: Miroslav Ilić, Clinic for Thoracic Surgery, Institute for Pulmonary Diseases of Vojvodina, Put doktora Goldmana br. 4, 21204 Sremska Kamenica, Serbia. Telephone: +381/21/480-5100 email: drmiroslavilic@ gmail.com Funding: The authors declare that they have no conflict of interest. This research did not receive any financial support. Conflict of interest: None. Abstract The obesity epidemic has burdened healthcare systems worldwide. Bariatric surgery is currently the most effective method for long-term weight loss in obese adults, but the exact mechanism of weight loss is poorly understood. Bariatric procedures were initially classified by their presumed mechanism of action into restrictive, malabsoptive, or mixed procedures; however, due to recent advancements in the field of neuroendocrinology, hormones are increasing being recognized as important regulators of satiation, hunger, and energy expenditure. Studies examining changes in gut hormones following bariatric surgery have yielded conflicting results and the relationship between these hormones and weight loss is nothing but clear. This review will summarize the effect of Roux en Y gastric bypass, sleeve gastrectomy and adjustable gastric banding on various gut hormones including ghrelin, cholecystokinin, glucagon-like polypeptide-1, peptide YY3, and pancreatic polypeptide. Furthermore, the relationship between these hormones and weight loss will be examined. Miroslav Ilić1, Fuad Pašić2, Lora Kirigin3, Gorana Mirošević3, Miroslav Bekavac Bešlin4

P. Pervan,1,* P. Lazić,2,4,† M. Petrović,1 I. Šrut Rakić,1 I. Pletikosić,1 M. Kralj,1,4 M. Milun,1 and T. Valla3 1Institut za fiziku, Bijenička 46, HR-10000, Zagreb, Croatia, 2Institut Ruđer Bošković, Bijenička 54, 10000, Zagreb, Croatia, 3Department of Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA 4Center of Excellence for Advanced Materials and Sensing Devices, Bijenička 46, HR-10000, Zagreb, Croatia (Received 20 August 2015; revised manuscript received 12 November 2015; published 10 December 2015)

Background and aims Proton pump inhibitors (PPIs) are among the top 10 most widely used drugs in the world. PPI use has been associated with an increased risk of enteric infections, most notably Clostridium difficile. The gut microbiome plays an important role in enteric infections, by resisting or promoting colonisation by pathogens. In this study, we investigated the influence of PPI use on the gut microbiome. Methods The gut microbiome composition of 1815 individuals, spanning three cohorts, was assessed by tag sequencing of the 16S rRNA gene. The difference in microbiota composition in PPI users versus non-users was analysed separately in each cohort, followed by a meta-analysis. Results 211 of the participants were using PPIs at the moment of stool sampling. PPI use is associated with a significant decrease in Shannon's diversity and with changes in 20% of the bacterial taxa (false discovery rate <0.05). Multiple oral bacteria were over-represented in the faecal microbiome of PPI-users, including the genus Rothia (p=9.8×10−38). In PPI users we observed a significant increase in bacteria: genera Enterococcus, Streptococcus, Staphylococcus and the potentially pathogenic species Escherichia coli. Conclusions The differences between PPI users and non-users observed in this study are consistently associated with changes towards a less healthy gut microbiome. These differences are in line with known changes that predispose to C. difficile infections and can potentially explain the increased risk of enteric infections in PPI users. On a population level, the effects of PPI are more prominent than the effects of antibiotics or other commonly used drugs.

Viral infections augment immediate and late allergic responses in the lungs of patients with allergic asthma. Certain viruses that typically exacerbate asthma have been noted to induce release of the cytokine interleukin-11 (IL-11) which is associated with airway hyperreactivity (AHR). The aim of study: To determine the frequency of influenza-like illness in patients with allergic asthma on immunotherapy compared to the patients with allergic asthma receiving only antiasthmatic pharmacotherapy during the period of 1-year follow up. Methods: In our study, we included 60 patients with allergic asthma, both genders who were subsequently divided into two treatment groups. Study group included 30 patients who received immunotherapy (immunotherapy group) and control group included 30 patients treated with standard pharmacotherapy, but not with immunotherapy (GINA proposal). Results: There was a significant difference in influenza-like illness (ILI) between immunotherapy and control group of patients. A significantly higher percentages of patients in control group experienced cold and/or flu syndrome compared to immunotherapy group, which was observed at the 2nd, 3rd and 4th trimester (X2= 20.480 p=0.0001). During the first trimester there was no difference in the number of patients with the cold/flu symptoms between the immunotherapy and control group. During the 2nd trimester, there was a significant decrease in the number of patients with cold/flu symptoms 3/30 (10%) in the immunotherapy group, while in the control group there was significantly higher number of patients with the cold/flu symptoms (11/30 (36 %)). In the 3rd and 4th trimester the frequency of patients with cold/flu symptoms was unchanged compared to the 2nd trimester in the immunotherapy group, while in the control group the frequency of patients with cold/flu symptoms increased from 20/30 (66%) at the 3rd to 27/30 (90%) in the 4th trimester. The number of patients reported to the physician due to bronchial hyperreactivity was dependent on the immunotherapy treatment (p=0.0001) Conclusions: The frequency of influenza-like illness occurrence was significantly lower in patients treated with immunotherapy during one year of follow-up compared to the patients treated with antiasthmatic pharmacotherapy. The percentage of patients with influenza-like illness was 10% in the patients treated with immunotherapy at third and fourth trimester of the follow-up, whilst in patients on antiasthmatic pharmacotherapy, the percentage of patients with influenza-like illness increased from 66% in the third to 90% in the fourth trimester.