Small intestinal bacterial overgrowth syndrome

A double-blind placebo-controlled randomized trial on probiotics in small bowel bacterial overgrowth in children treated with omeprazole

OBJECTIVE

To evaluate the incidence of small bowel bacterial overgrowth (SBBO) in children treated with omeprazole, and to test whether probiotics influence the incidence.

METHODS

A double-blinded, placebo-controlled trial was performed in 70 children treated orally during four weeks with 20mg omeprazole per day. Lactobacillus rhamnosus R0011 (1.9×10(9) cfu) and Lactobacillus acidophilus R0052 (0.1×10(9) cfu) were simultaneously given daily to 36 subjects (probiotic group), while 34 subjects received placebo (placebo group). The diagnosis of SBBO was based on the development of suggestive symptoms, in combination with a positive glucose breath test.

RESULTS

After one month of proton pump inhibitor (PPI) treatment, 30% (21/70) had a positive breath test suggesting SBBO; of these 62% were symptomatic. Five children developed SBBO-like symptoms, but had a negative breath test; and 44 (63%) were symptom free and had a negative breath test. There was no difference in the incidence of positive breath tests in the probiotic versus the placebo group (33% vs 26.5%; p=0.13).

CONCLUSIONS

Since symptoms suggesting SBBO developed in 26% of PPI-treated children, and since the glucose breath test was abnormal in 72% of these, this side-effect should be more frequently considered. The probiotic tested did not decrease the risk to develop SBBO.

Chronic radiation enteritis and malnutrition

Radiation enteritis is defined as the loss of absorptive capacity of the intestine following irradiation, which is most commonly seen after radiotherapy for pelvic and abdominal malignancies. It is divided into acute and chronic forms and usually presents with diarrhea and malabsorption. Malnutrition is a common complication of chronic radiation enteritis (CRE). We reviewed the etiology, prevalence, symptoms, diagnosis and management of CRE and CRE with malnutrition in this article. Functional short bowel syndrome as a cause of malnutrition in CRE is also considered. The diagnostic work-up includes serum markers, endoscopy, cross-sectional imaging and the exclusion of alternative diagnoses such as recurrent malignancy. Management options of CRE include dietary manipulation, anti-motility agents, electrolyte correction, probiotics, parenteral nutrition, surgical resection and small bowel transplantation. Treatment may also be required for coexisting conditions including vitamin B12 deficiency, bile acid malabsorption and depression.

Evaluation of small intestine bacterial overgrowth in patients with functional dyspepsia through H2 breath test

CONTEXT

Functional dyspepsia is a condition in which symptoms are not related to organic underlying disease; its pathogenesis is not well known. The small intestinal bacterial overgrowth (SIBO) is characterized by the increase in the number and/or type of colonic bacteria in the upper gastrointestinal tract. The hypothesis of SIBO being associated to functional dyspepsia must be considered, since the impaired motility of the gastrointestinal tract is one of the main etiologic factors involved on both pathologies.

OBJECTIVE

To determine if there is SIBO in patients with functional dyspepsia.

METHODS

Case-control study, evaluating 34 patients: 23 functional dyspeptic and 11 non-dyspeptic (control group). Questionnaire applied based on Rome III criteria. The patients underwent H2-lactulose breath test, considered positive when: H2 peak exceeding 20 ppm, in relation to fasting, or two peaks exceeding 10 ppm sustained until 60 minutes.

RESULTS

Of the 23 dyspeptic patients, 13 (56.5%) obtained positive results for SIBO trough the H2-lactulose breath test. On control group, SIBO was not observed. The association between the dyspeptic group and the control group regarding SIBO was statistically significant, with P = 0.0052. In the group of dyspeptic patients, 12 (52.2%) were using proton pump inhibitor; of these 9 (75%) were positive for SIBO. In the control group, none of the 11 patients used proton pump inhibitors and SIBO was not observed. The association of the dyspeptic group using proton pump inhibitor that were positive for SIBO and the control group was statistically significant, with P = 0.0011.

CONCLUSION

It was found that, patients with functional dyspepsia presented SIBO, when they underwent to H2-lactulose breath test, compared to the non-dyspeptic. In addition, it was observed a higher prevalence of SIBO in dyspeptic patients that were using proton pump inhibitors, compared to control group.

Dysmotility and proton pump inhibitor use are independent risk factors for small intestinal bacterial and/or fungal overgrowth

BACKGROUND

Whether intestinal dysmotility and the use of a proton pump inhibitor (PPI) either independently or together contributes to small intestinal bacterial overgrowth (SIBO), and/or small intestinal fungal overgrowth (SIFO) is not known.

AIM

To investigate the role of dysmotility and PPI use in patients with persistent gastrointestinal complaints.

METHODS

Patients with unexplained gastrointestinal symptoms and negative endoscopy/radiology tests completed a validated symptom questionnaire and underwent 24-h ambulatory antro-duodeno-jejunal manometry (ADJM). Simultaneously, duodenal aspirate was obtained for aerobic, anaerobic and fungal culture. Dysmotility was diagnosed by (>2): absent phase III MMC, absent/diminished postprandial response, diminished amplitude of antral/intestinal phasic activity, impaired antro-duodenal coordination. Bacterial growth ≥10³ CFU/mL or fungal growth was considered evidence for SIBO/SIFO. PPI use was documented. Correlation of symptoms with presence of SIBO or SIFO was assessed.

RESULTS

One hundred and fifty subjects (M/F = 47/103) were evaluated; 94/150 (63%) had overgrowth: 38/94 (40%) had SIBO, 24/94 (26%) had SIFO and 32/94 (34%) had mixed SIBO/SIFO. SIBO was predominately due to Streptococcus, Enterococcus, Klebsiella and E. coli. SIFO was due to Candida. Eighty of 150 (53%) patients had dysmotility and 65/150 (43%) used PPI. PPI use (P = 0.0063) and dysmotility (P = 0.0003) were independent significant risk factors (P < 0.05) for overgrowth, but together did not pose additional risk. Symptom profiles were similar between those with or without SIBO/SIFO.

CONCLUSIONS

Dysmotility and PPI use were independent risk factors for SIBO or SIFO and were present in over 50% of subjects with unexplained gastrointestinal symptoms. Diagnosis of overgrowth requires testing because symptoms were poor predictors of overgrowth.

Canine breed predispositions for marked hypocobalaminaemia or decreased folate concentration assessed by a laboratory survey

OBJECTIVE

The aim of this study was to determine canine breed predispositions for decreased serum folate or markedly decreased cobalamin concentrations.

METHODS

Retrospective analysis of samples from dogs that had serum folate and cobalamin concentrations measured, from 1990 to 2002 at the Comparative Gastroenterology Laboratory of Liverpool, were enrolled. A total of 13,069 samples were analysed. Those with trypsin-like immunoreactivity < 5·0 lg/L were excluded, and only breeds with at least 30 individuals tested were further analyzed. Breed predisposition was determined by calculating odds ratios and 95% confidence intervals for hypocobalaminaemia or decreased folate concentration. Significance was tested with a two-sided Fisher's exact test, and the level of statistical significance was set at P<0·05.

RESULTS

A total of 9960 dogs fulfilled the inclusion criteria. Forty breeds contained at least 30 individuals. Predispositions for hypocobalaminaemia were identified in shar peis, Staffordshire bull terriers, German shepherd dogs and mixed breeds. Predispositions for decreased folate concentration were found in golden retrievers and boxers.

CLINICAL SIGNIFICANCE

Predisposition for marked hypocobalaminaemia and decreased folate concentration differed between breeds. The shar peis had a markedly increased odds ratio for hypocobalaminaemia, as previously reported in North America, but other at-risk breeds were also identified.

Pancreatic surgery: indications, complications, and implications for nutrition intervention

Pancreatic surgery is a complicated procedure leaving postoperative patients with an altered gastrointestinal (GI) anatomy and a potential for further surgical complications such as leaks and fistulas. Beyond surgical complications, these patients are prone to delayed gastric emptying, fat malabsorption, and hyperglycemia, with early satiety and poor appetite further compromising nutrition status. Many of these patients are malnourished prior to this major surgical procedure, and significant weight loss is common postoperatively. Does this affect their outcome? There seems to be a lack of consensus in this patient population regarding how to optimize nutrition and limit potential deleterious effects of this surgery. It is important to first understand the underlying disease condition and the effects to the gland, different forms of surgery with subsequent GI alterations, and common surgical and digestive complications. Once this is reviewed, existing nutrition support literature will be explored in attempts to determine the best nutrition management in this patient population.

Effect of Helicobacter pylori eradication on serum ghrelin and obestatin levels

AIM: To investigate changes in serum ghrelin and obestatin levels before and after Helicobacter pylori (H. pylori) eradication.

METHODS: A total of 92 patients presenting with symptoms of dyspepsia were enrolled in the study. Upper endoscopy was performed on all patients and used to diagnose H. pylori infection according to the presence of characteristic histopathological findings; seventy patients were diagnosed with H. pylori infection and the remaining 22 non-infected patients were classified as healthy controls. H. pylori eradication was accomplished by administering the classical triple therapy drug regimen, consisting of lansoprazole 30 mg bid, amoxicillin 1 g bid, and clarithromycin 500 mg tid for 14 d. The eradication of H. pylori was assessed with C¹⁴-urea breath test, which was performed at eight weeks after treatment. Levels of serum active ghrelin and obestatin were assessed at beginning of the study (prior to treatment) and after eight weeks. The levels were comparatively analyzed between the H. pylori negative control group, the H. pylori eradicated group, and the H. pylori non-eradicated group.

RESULTS: A total of 92 patients, 50 females and 42 males with a mean age of 38.2 ± 11.9 years (range: 19-64), were analyzed. H. pylori eradication success was achieved in 74.3% (52/70) of H. pylori positive patients. The initial levels of ghrelin in the H. pylori positive and control cases were 63.6 ± 19.8 pg/mL and 65.1 ± 19.2 pg/mL (P = 0.78), respectively, and initial obestatin levels were 771 ± 427 pg/mL and 830 ± 296 pg/mL (P = 0.19), respectively. The difference between the initial levels and the week 8 levels of ghrelin and obestatin in the control group was insignificant [4.5% (P = 0.30) and -0.9% (P = 0.65), respectively]. The difference between the initial and week 8 levels of ghrelin and obestatin in the H. pylori non-eradicated group were also insignificant [0.9% (P = 0.64) and 5.3% (P = 0.32), respectively]. The H. pylori eradicated group had a greater change in obestatin levels when compared to the control and the non-eradicated groups (148 ± 381 pg/mL vs -12 ± 138 pg/mL and -72.8 ± 203 pg/mL, respectively, P = 0.015), while decreases in ghrelin levels were insignificant (-7.2 pg/mL vs -1.4 pg/mL and -1.9 pg/mL, respectively, P = 0.52). The ghrelin/obestatin ratio for the initial and week 8 levels changed significantly in only the H. pylori eradicated group (0.11 vs 0.08, respectively, P = 0.015). For overweight patients (as designated by body mass index), we observed significant increases in obestatin levels in the eradicated group as compared to non-eradicated group (201 ± 458 pg/mL vs -5 ± 81 pg/mL, respectively, P = 0.02). In the H. pylori-eradicated group, the levels did not differ between the sexes for ghrelin (-6.3 ± 26.9 pg/mL vs -8.0 ± 24.0 pg/mL, respectively, P = 0.97) or obestatin (210 ± 390 pg/mL vs 96 ± 372 pg/mL, respectively, P = 0.23).

CONCLUSION: Serum levels of ghrelin decreased while obestatin levels increased in H. pylori eradicated subjects, especially in overweight and male patients.

Feline gastrointestinal microbiota

The close relationship between gastrointestinal (GI) microbiota and its host has an impact on the health status of an animal that reaches beyond the GI tract. A balanced microbiome stimulates the immune system, aids in the competitive exclusion of transient pathogens and provides nutritional benefits to the host. With recent rapid advances in high-throughput sequencing technology, molecular approaches have become the routinely used tools for ecological studies of the feline microbiome, and have revealed a highly diverse and complex intestinal ecosystem in the feline GI tract. The major bacterial groups are similar to those found in other mammals, with Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria constituting more than 99% of intestinal microbiota. Several nutritional studies have demonstrated that the feline microbiota can be modulated by the amount of soluble fibers (i.e., prebiotics) and macronutrients (i.e., protein content) in the diet. Initial clinical studies have suggested the presence of a dysbiosis in feline inflammatory bowel disease (IBD). Recently, metagenomic approaches have attempted to characterize the microbial gene pool. However, more studies are needed to describe the phylogenetic and functional changes in the intestinal microbiome in disease states and in response to environmental and dietary modulations. This paper reviews recent studies cataloging the microbial phylotypes in the GI tract of cats.

Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances: Part II - contemporary contextual research

In recent years there has been a renewed interest concerning the ways in which the gastrointestinal tract – its functional integrity and microbial residents – might influence human mood (e.g. depression) and behavioral disorders. Once a hotbed of scientific interest in the early 20th century, this area lay dormant for decades, in part due to its association with the controversial term ‘autointoxication’. Here we review contemporary findings related to intestinal permeability, small intestinal bacterial overgrowth, lipopolysaccharide endotoxin (LPS) exposure, D-lactic acid, propionic acid, and discuss their relevance to microbiota and mental health. In addition, we include the context of modern dietary habits as they relate to depression, anxiety and their potential interaction with intestinal microbiota.

PAR-2-mediated control of barrier function and motility differs between early and late phases of postinfectious gut dysfunction in the rat

Proteinase-activated receptor-2 (PAR-2) and mast cell (MC) mediators contribute to inflammatory and functional gastrointestinal disorders. We aimed to characterize jejunal PAR-2-mediated responses and the potential MC involvement in the early and late phases of a rat model of postinfectious gut dysfunction. Jejunal tissues of control and Trichinella spiralis-infected (14 and 30 days postinfection) rats, treated or not with the MC stabilizer, ketotifen, were used. Histopathology and immunostaining were used to characterize inflammation, PAR-2 expression, and mucosal and connective tissue MCs. Epithelial barrier function (hydroelectrolytic transport and permeability) and motility were assessed in vitro in basal conditions and after PAR-2 activation. Intestinal inflammation on day 14 postinfection (early phase) was significantly resolved by day 30 (late phase) although MC counts and epithelial permeability remained increased. PAR-2-mediated ion transport (Ussing chambers, in vitro) and epithelial surface PAR-2 expression were reduced in the early phase, with a trend toward normalization during the late phase. In control conditions, PAR-2 activation (organ bath) induced biphasic motor responses (relaxation followed by excitation). At 14 days postinfection, spontaneous contractility and PAR-2-mediated relaxations were enhanced; motor responses were normalized on day 30. Postinfectious changes in PAR-2 functions were not affected by ketotifen treatment. We concluded that, in the rat model of Trichinella spiralis infection, alterations of intestinal PAR-2 function and expression depend on the inflammatory phase considered. A lack of a ketotifen effect suggests no interplay between MCs and PAR-2-mediated motility and ion transport alterations. These observations question the role of MC mediators in PAR-2-modulating postinfectious gut dysfunction.

Update on chronic diarrhea: a run-through for the clinician

Chronic diarrhea is a common patient complaint, with an estimated prevalence of 5 %. Diarrhea is defined as >200 g/day of stool with decreased consistency, and chronic diarrhea is defined as lasting more than 4 weeks. The purpose of this review is to guide the clinician's diagnostic evaluation and management of chronic diarrhea, rather than providing a textbook comprehensive review of the subject, focusing on the patient in developed countries and excluding the immune suppressed patient. While the investigation and treatment of chronic diarrhea can be challenging due to its myriad causes, when the clinician employs a practical approach, dividing chronic diarrhea into bloody, fatty, and watery causes, it simplifies and streamlines the work-up and management plan and leads to improved patient outcomes.

Erkrankungen und Therapieformen des unteren Gastrointestinaltrakts

Duodenalatresien sind Hemmungsfehlbildungen und können proximal oder distal der Papilla Vateri entstehen, wobei die präpapillären Obstruktionen selten sind. Grundsätzlich kann zwischen einer Membranatresie und einer Defektatresie unterschieden werden. Die Unterscheidung beruht nicht nur auf embryologischen Gesichtspunkten, sondern hat auch eine klinische Bedeutung: Bei der Membranatresie kann die quergestellte, partiell offene oder geschlossene Membran weit in den distalen Duodenalanteil reichen („Windsackphänomen“), was zu diagnostischen und auch intraoperativen Problemen führen kann. Ein Pancreas anulare findet sich bei etwa 20 % aller Patienten mit Duodenalatresie.

Ileocecal valve dysfunction in small intestinal bacterial overgrowth: a pilot study

AIM

To explore whether patients with a defective ileocecal valve (ICV)/cecal distension reflex have small intestinal bacterial overgrowth.

METHODS

Using a colonoscope, under conscious sedation, the ICV was intubated and the colonoscope was placed within the terminal ileum (TI). A manometry catheter with 4 pressure channels, spaced 1 cm apart, was passed through the biopsy channel of the colonoscope into the TI. The colonoscope was slowly withdrawn from the TI while the manometry catheter was advanced. The catheter was placed across the ICV so that at least one pressure port was within the TI, ICV and the cecum respectively. Pressures were continuously measured during air insufflation into the cecum, under direct endoscopic visualization, in 19 volunteers. Air was insufflated to a maximum of 40 mmHg to prevent barotrauma. All subjects underwent lactulose breath testing one month after the colonoscopy. The results of the breath tests were compared with the results of the pressures within the ICV during air insufflation.

RESULTS

Nineteen subjects underwent colonoscopy with measurements of the ICV pressures after intubation of the ICV with a colonoscope. Initial baseline readings showed no statistical difference in the pressures of the TI and ICV, between subjects with positive lactulose breath tests and normal lactulose breath tests. The average peak ICV pressure during air insufflation into the cecum in subjects with normal lactulose breath tests was significantly higher than cecal pressures during air insufflation (49.33 ± 7.99 mmHg vs 16.40 ± 2.14 mmHg, P = 0.0011). The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflations in subjects with normal lactulose breath tests was significantly higher (280.72% ± 43.29% vs 100% ± 0%, P = 0.0006). The average peak ICV pressure during air insufflation into the cecum in subjects with positive lactulose breath tests was not significantly different than cecal pressures during air insufflation 21.23 ± 3.52 mmHg vs 16.10 ± 3.39 mmHg. The average percentage difference of the area under the pressure curve of the ICV from the cecum during air insufflation was not significantly different 101.08% ± 7.96% vs 100% ± 0%. The total symptom score for subjects with normal lactulose breath tests and subjects with positive lactulose breath tests was not statistically different (13.30 ± 4.09 vs 24.14 ± 6.58). The ICV peak pressures during air insufflations were significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.005). The average percent difference of the area under the pressure curve in the ICV from cecum was significantly higher in subjects with normal lactulose breath tests than in subjects with positive lactulose breath tests (P = 0.0012). Individuals with positive lactulose breath tests demonstrated symptom scores which were significantly higher for the following symptoms: not able to finish normal sized meal, feeling excessively full after meals, loss of appetite and bloating.

CONCLUSION

Compared to normal, subjects with a positive lactulose breath test have a defective ICV cecal distension reflex. These subjects also more commonly have higher symptom scores.

Systemic sclerosis--challenges for clinical practice

The management of patients with systemic sclerosis (SSc) can be challenging because disease-associated damage is often difficult to reverse and curative therapies are not yet available. Early identification and appropriate monitoring of patients with SSc is, therefore, critical so that active disease can be controlled and tissue damage prevented or delayed. However, early diagnosis of SSc is often difficult because the early clinical stages of the disease can be very similar to that of other autoimmune conditions. Screening for major organ manifestations of SSc, particularly interstitial lung disease, pulmonary hypertension, renal involvement and cardiac disease is a priority because involvement of these organs is associated with shorter life expectancies and early intervention might prevent disease progression. The prevention and management of digital ischaemia is also important as appropriate therapy often prevents substantial morbidity and functional loss. Treating gastrointestinal dysmotility can usually be managed using proton pump inhibitors and promotility agents, although in severe cases total parenteral nutrition is required. Calcinosis in patients with SSc is another common challenge that requires appropriate disease management and pain control. Each of these topics, which are relevant to both physicians and patients with SSc, are reviewed in further detail herein.

Methane production and small intestinal bacterial overgrowth in children living in a slum

AIM

To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.

METHODS

This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H(2)) and methane (CH(4)) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H(2) ≥ 20 ppm or CH(4) ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.

RESULTS

Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001). Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017).

CONCLUSION

Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for methane production in the colon.

[Proton-pump inhibitor therapy and small bowel bacterial contamination]

There are several causes of small bowel contamination. The effects of the long-term proton pump inhibitor treatment on the development of bowel symptoms and/or small intestinal bacterial overgrowth have been highlighted only in the past decade. The main diagnostic method is the hydrogen breath test that gives quantitative results with a simple, non-invasive procedure. There is a limited number of publications in the literature about the effects of proton pump inhibitor drugs on bowel bacterial milieau. Our results based on the investigations of two medical centres in Budapest show consistency with international data: the positive hydrogen breath test was present in 21% of the population using long-term proton pump inhibitors. In uncomplicated cases, symptom-free condition could be reached with probiotics, whereas in long lasting, chronic small intestinal bacterial overgrowth, antibiotic treatment should be considered. Rifaximin, a non-absorbable antibiotic showed high efficacy in the treatment of small intestinal bacterial overgrowth, with fewer side effects compared to systemic antibiotics.

A case of nonalcoholic steatohepatitis and small intestinal bacterial overgrowth with peripheral edema caused by intestinal bypass surgery and relieved by repair

Intestinal bypass surgery, particularly jejuno-ileal bypass surgery, performed for the purpose of weight reduction may cause an unexpected exacerbation of nonalcoholic steatohepatitis (NASH). Here, we report a case of NASH caused by small intestinal bacterial overgrowth, which developed after jejuno-colic bypass surgery and resolved dramatically after surgical correction.

Contributions of the microbial hydrogen economy to colonic homeostasis

Colonic gases are among the most tangible features of digestion, yet physicians are typically unable to offer long-term relief from clinical complaints of excessive gas. Studies characterizing colonic gases have linked changes in volume or composition with bowel disorders and shown hydrogen gas (H(2)), methane, hydrogen sulphide, and carbon dioxide to be by-products of the interplay between H(2)-producing fermentative bacteria and H(2) consumers (reductive acetogens, methanogenic archaea and sulphate-reducing bacteria [SRB]). Clinically, H(2) and methane measured in breath can indicate lactose and glucose intolerance, small intestinal bacterial overgrowth and IBS. Methane levels are increased in patients with constipation or IBS. Hydrogen sulphide is a by-product of H(2) metabolism by SRB, which are ubiquitous in the colonic mucosa. Although higher hydrogen sulphide and SRB levels have been detected in patients with IBD, and to a lesser extent in colorectal cancer, this colonic gas might have beneficial effects. Moreover, H(2) has been shown to have antioxidant properties and, in the healthy colon, physiological H(2) concentrations might protect the mucosa from oxidative insults, whereas an impaired H(2) economy might facilitate inflammation or carcinogenesis. Therefore, standardized breath gas measurements combined with ever-improving molecular methodologies could provide novel strategies to prevent, diagnose or manage numerous colonic disorders.

Nutritional deficiencies after bariatric surgery

Lifestyle intervention programmes often produce insufficient weight loss and poor weight loss maintenance. As a result, an increasing number of patients with obesity and related comorbidities undergo bariatric surgery, which includes approaches such as the adjustable gastric band or the 'divided' Roux-en-Y gastric bypass (RYGB). This Review summarizes the current knowledge on nutrient deficiencies that can develop after bariatric surgery and highlights follow-up and treatment options for bariatric surgery patients who develop a micronutrient deficiency. The major macronutrient deficiency after bariatric surgery is protein malnutrition. Deficiencies in micronutrients, which include trace elements, essential minerals, and water-soluble and fat-soluble vitamins, are common before bariatric surgery and often persist postoperatively, despite universal recommendations on multivitamin and mineral supplements. Other disorders, including small intestinal bacterial overgrowth, can promote micronutrient deficiencies, especially in patients with diabetes mellitus. Recognition of the clinical presentations of micronutrient deficiencies is important, both to enable early intervention and to minimize long-term adverse effects. A major clinical concern is the relationship between vitamin D deficiency and the development of metabolic bone diseases, such as osteoporosis or osteomalacia; metabolic bone diseases may explain the increased risk of hip fracture in patients after RYGB. Further studies are required to determine the optimal levels of nutrient supplementation and whether postoperative laboratory monitoring effectively detects nutrient deficiencies. In the absence of such data, clinicians should inquire about and treat symptoms that suggest nutrient deficiencies.

Bacterial flora as a cause or treatment of chronic diarrhea

Intestinal microflora can be considered an organ of the body. It has several functions in the human gut, mostly metabolic and immunologic, and constantly interacts with the intestinal mucosa in a delicate equilibrium. Chronic diarrhea is associated with an alteration of gut microbiota when a pathogen invades the gut and also in several conditions associated with intestinal mucosal damage or bowel dysfunction, as in inflammatory bowel disease, irritable bowel syndrome, or small bowel bacterial overgrowth. This article discusses the basis of gut microbiota modulation. Evidence for the efficacy of gut microbiota modulation in chronic conditions is also discussed.

Diabetic gastrointestinal autonomic neuropathy: current status and new achievements for everyday clinical practice

Gastrointestinal symptoms occur frequently among patients with diabetes mellitus and are associated with considerable morbidity. Diabetic gastrointestinal autonomic neuropathy represents a complex disorder with multifactorial pathogenesis, which is still not well understood. It appears to involve a spectrum of metabolic and cellular changes that affect gastrointestinal motor and sensory control. It may affect any organ in the digestive system. Clinical manifestations are often underestimated, and therefore autonomic neuropathy should be suspected in all diabetic patients with unexplained gastrointestinal symptoms. Advances in technology have now enabled assessment of gastrointestinal motor function. Moreover, novel pharmacological approaches, along with endoscopic and surgical treatment options, contribute to improved outcomes. This review summarises the progress achieved in diabetic gastrointestinal autonomic neuropathy during the last years, focusing on clinical issues of practical importance to the everyday clinician.

The gut microbiota and irritable bowel syndrome: friend or foe?

Progress in the understanding of the pathophysiology of irritable bowel syndrome (IBS), once thought to be a purely psychosomatic disease, has advanced considerably and low-grade inflammation and changes in the gut microbiota now feature as potentially important. The human gut harbours a huge microbial ecosystem, which is equipped to perform a variety of functions such as digestion of food, metabolism of drugs, detoxification of toxic compounds, production of essential vitamins, prevention of attachment of pathogenic bacteria to the gut wall, and maintenance of homeostasis in the gastrointestinal tract. A subset of patients with IBS may have a quantitative increase in bacteria in the small bowel (small intestinal bacterial overgrowth). Qualitative changes in gut microbiota have also been associated with IBS. Targeting the gut microbiota using probiotics and antibiotics has emerged as a potentially effective approach to the treatment of this, hitherto enigmatic, functional bowel disorder. The gut microbiota in health, quantitative and qualitative microbiota changes, and therapeutic manipulations targeting the microbiota in patients with IBS are reviewed in this paper.

Acute pancreatitis with pancreatic abscess secondary to sealed jejunal diverticular perforation

Although most cases of acute pancreatitis are attributed to gallstones or alcohol, many remain idiopathic. The authors describe a case of acute pancreatitis in a 75-year-old gentleman who presented with acute epigastric pain, fevers and shortness of breath. Serum amylase was 2164. CT showed free mesenteric air, and a partly cystic/partly gas-containing mass in the uncinate lobe of the pancreas. Gastrograffin meal revealed duodenal and jejunal diverticular disease, but no contrast leak. Further CT analysis pinpointed fine tracts of air leading from a jejunal diverticulum up toward the pancreas, suggesting causation by a sealed jejunal diverticular perforation. He responded well to intravenous antibiotics and conservative management. Although small bowel diverticular disease is linked to chronic pancreatitis, evidence for association with acute pancreatitis is scarce. The authors believe this is the first reported case of jejunal diverticular disease causing acute pancreatitis, and it highlights micro-perforation as a potential disease mechanism.

Noncoeliac enteropathy: the differential diagnosis of villous atrophy in contemporary clinical practice

BACKGROUND

Duodenal villous atrophy (DVA) is a key diagnostic finding in coeliac disease (CD). However, the differential diagnosis for this finding is broad.

AIM

To identify conditions causing noncoeliac enteropathy (NCE) with villous atrophy and methods to differentiate between CD and NCE in clinical practice.

METHODS

Through record review we identified patients with DVA due to conditions other than CD. Patient demographics, clinical features and relevant investigations were compared with CD patients. Rates of CD misdiagnosis, and response to treatments were recorded.

RESULTS

Thirty cases of NCE were identified with ten different aetiologies. Unspecified immune-mediated enteropathy was the most common aetiology; affecting 10 patients. Gastrointestinal symptoms were more common in NCE than those in CD patients (P < 0.01). Twenty of the 24 NCE patients tested were HLA-DQ2/DQ8 negative. Twenty-six NCE patients were negative for IgA tissue transglutaminase (tTG) (P = 0.0001). Intraepithelial lymphocytosis was absent in 10 (33.3%) patients. Twenty-one NCE patients initially misdiagnosed with CD and one with gluten intolerance were prescribed a gluten free diet (GFD). Fifteen of 22 had repeat biopsy and none showed histological improvement.

CONCLUSIONS

Although coeliac disease is the most common cause of DVA, noncoeliac enteropathy is not rare and may easily be mistaken for coeliac disease. Noncoeliac enteropathy is suggested by a normal initial tTG (87%), lack of intraepithelial lymphocytosis on biopsy, and lack of histological response to a gluten free diet. Subjective response to gluten free diet has poor predictive value for coeliac disease. Noncoeliac enteropathy can often be confirmed by negative HLA-DQ2/DQ8 testing and targeted investigations can ascertain a definitive aetiology in most cases.

[Gluten-sensitive enteropathy and functional dyspepsia]

Gluten-sensitive enteropathy (GSE) is increasingly diagnosed in adults. The symptoms of this disease can overlap with those of functional dyspepsia. The prevalence of GSE in dyspepsia has been reported to be 1.2-6.2% and could be higher if the entire spectrum of lesions related to gluten sensitivity, including lymphocytic enteropathy, is considered. Patients with dyspepsia secondary to GSE could be mistakenly diagnosed with functional dyspepsia unless upper gastrointestinal endoscopy is completed with duodenal biopsy and immunostaining for intraepithelial lymphocytes. A missed diagnosis could have major consequences in terms of morbidity and mortality and quality of life. Consequently, endoscopic study of patients with dyspepsia should be completed by duodenal biopsy when there are symptoms suggestive of GSE.

Difficulty in walking 10 years after gastric surgery

A 65-year-old gentleman presented with a history of abdominal distension and difficulty in walking 10 years after a Polya partial gastrectomy. Clinical history and neurological examination suggested an axonal sensory neuropathy. A computed tomographic scan of the abdomen showed a large afferent jejunal loop, and a hydrogen breath test confirmed small-bowel bacterial overgrowth secondary to the blind loop syndrome. Serological tests revealed low copper levels, which are a cause of a myeloneuropathy. The trace element deficiency occurred as a consequence of small-bowel bacterial overgrowth, and with antibiotic treatment of the bacterial overgrowth and copper supplementation his symptoms markedly improved.

Bacteriocinogeny in experimental pigs treated with indomethacin and Escherichia coli Nissle

AIM: To evaluate bacteriocinogeny in short-term high-dose indomethacin administration with or without probiotic Escherichia coli Nissle 1917 (EcN) in experimental pigs.

METHODS: Twenty-four pigs entered the study: Group A (controls), Group B (probiotics alone), Group C (indomethacin alone) and Group D (probiotics and indomethacin). EcN (3.5 × 10¹⁰ bacteria/d for 14 d) and/or indomethacin (15 mg/kg per day for 10 d) were administrated orally. Anal smears before and smears from the small and large intestine were taken from all animals. Bacteriocin production was determined with 6 different indicator strains; all strains were polymerase chain reaction tested for the presence of 29 individual bacteriocin-encoding determinants.

RESULTS: The general microbiota profile was rather uniform in all animals but there was a broad diversity in coliform bacteria (parallel genotypes A, B1, B2 and D found). In total, 637 bacterial strains were tested, mostly Escherichia coli (E. coli). There was a higher incidence of non-E. coli strains among samples taken from the jejunum and ileum compared to that of the colon and rectum indicating predominance of E. coli strains in the large intestine. Bacteriocinogeny was found in 24/77 (31%) before and in 155/560 (28%) isolated bacteria at the end of the study. Altogether, 13 individual bacteriocin types (out of 29 tested) were identified among investigated strains. Incidence of four E. coli genotypes was equally distributed in all groups of E. coli strains, with majority of genotype A (ranging from 81% to 88%). The following types of bacteriocins were most commonly revealed: colicins Ia/Ib (44%), microcin V (18%), colicin E1 (16%) and microcin H47 (6%). There was a difference in bacteriocinogeny between control group A (52/149, 35%) and groups with treatment at the end of the study: B: 31/122 (25%, P = 0.120); C: 43/155 (28%, P = 0.222); D: 29/134 (22%, P = 0.020). There was a significantly lower prevalence of colicin Ib, microcins H47 and V (probiotics group, P < 0.001), colicin E1 and microcin H47 (indomethacin group, P < 0.001) and microcins H47 and V (probiotics and indomethacin group, P = 0.025) compared to controls. Escherichia fergusonii (E. fergusonii) was identified in 6 animals (6/11 isolates from the rectum). One strain was non-colicinogenic, while all other strains of E. fergusonii solely produced colicin E1. All animals started and remained methanogenic despite the fact that EcN is a substantial hydrogen producer. There was an increase in breath methane (after the treatment) in 5/6 pigs from the indomethacin group (C).

CONCLUSION: EcN did not exert long-term liveability in the porcine intestine. All experimental pigs remained methanogenic. Indomethacin and EcN administered together might produce the worst impact on bacteriocinogeny.

Acne vulgaris, probiotics and the gut-brain-skin axis - back to the future?

Over 70 years have passed since dermatologists John H. Stokes and Donald M. Pillsbury first proposed a gastrointestinal mechanism for the overlap between depression, anxiety and skin conditions such as acne. Stokes and Pillsbury hypothesized that emotional states might alter the normal intestinal microflora, increase intestinal permeability and contribute to systemic inflammation. Among the remedies advocated by Stokes and Pillsbury were Lactobacillus acidophilus cultures. Many aspects of this gut-brain-skin unifying theory have recently been validated. The ability of the gut microbiota and oral probiotics to influence systemic inflammation, oxidative stress, glycemic control, tissue lipid content and even mood itself, may have important implications in acne. The intestinal microflora may also provide a twist to the developing diet and acne research. Here we provide a historical perspective to the contemporary investigations and clinical implications of the gut-brain-skin connection in acne.

Possible pathogenetic roles of abdominal surgery in irritable bowel syndrome

Recently, a plethora of studies have reported that irritably bowel syndrome (IBS) patients have increased incidences of abdominal surgeries, mainly gut surgeries. This high incidence of surgeries highlights the fact that the surgery was done because diagnosis of IBS was not suspected in them. It is then a matter of inquisitiveness as to why the diagnosis of IBS was missed in so many patients. Lack of clinical diagnostic sophistication could be one of the reasons. However, inspite of these facts, it has never been documented that the typical IBS like picture was present in these patients before surgery. Mostly, the preoperative complaints in negative appendectomy patients have been atypical pain syndromes. Thus we should also take into account the possibility that the typical IBS symptom profile was not present in these patients before surgery and that the surgical intervention could have resulted in subsequent development of complete picture of IBS. Infact, in one study, various surgical procedures were known to precede IBS symptoms, where they have also been conceptualized as one of the stressors which could lead to IB. Seeing from the other perspective, the etiological understanding of IBS in medical literature is still so preliminary that we have only been able to enumerate some possible factors. In such a scenario, we need to explore in detail the events which occur frequently in IBS patients, like abdominal surgery. Here, we hypothesize that any abdominal surgical intervention could itself be a reason for development of IBS. We provide evidences from literature in favor of two such possible mechanisms through which any abdominal surgical procedure could act resulting in development of IBS. In addition, we present the report of follow-up of 4 of our own patients where we specifically inquired about IBS before the appendectomy, which turned out to be negative. After 6 months of the followup, the patients developed symptoms which were diagnosable as IBS.

Contribution of the intestinal microbiota to human health: from birth to 100 years of age

Our intestinal tract is colonized since birth by multiple microbial species that show a characteristic succession in time. Notably the establishment of the microbiota in early life is important as it appears to impact later health. While apparently stable in healthy adults, the intestinal microbiota is changing significantly during aging. After 100 years of symbiosis marked changes have been observed that may relate to an increased level of intestinal inflammation. There is considerable interest in the microbiota in health and disease as it may provide functional biomarkers, the possibility to differentiate subjects, and avenues for interventions. This chapter reviews the present state of the art on the research to investigate the contribution of the intestinal microbiota to human health. Specific attention will be given to the healthy microbiota and aberrations due to disturbances such as celiac disease, irritable bowel syndrome, inflammatory bowel disease, obesity and diabetes, and non-alcoholic fatty liver disease.