Interplay between bile acid metabolism and microbiota in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) physiopathology is multifactorial and roles for both microbiota and bile acid (BA) modifications have been proposed. We investigated role of dysbiosis, transit pattern and BA metabolism in IBS.

METHODS

Clinical data, serum, and stool samples were collected in 15 healthy subjects (HS), 16 diarrhea-predominant (IBS-D) and 15 constipation-predominant IBS (IBS-C). Fecal microbiota composition was analyzed by real-time PCR. Sera and fecal BA profiles, 7α-C4 levels, and in vitro BA transformation activity by fecal microbiota were measured by mass spectrometry. Serum Fibroblast Growth Factor 19 (FGF19) was assayed by ELISA.

KEYS RESULTS

Dysbiosis was present in IBS patients with an increase in Escherichia coli in IBS-D patients (p = 0.03), and an increase in Bacteroides (p = 0.01) and Bifidobacterium (p = 0.04) in IBS-C patients. Sera primary and amino-conjugated BA were increased in IBS-D (63.5 ± 5.5%, p = 0.01 and 78.9 ± 6.3%, p = 0.03) and IBS-C patients (55.9 ± 5.5%, p = 0.04 and 65.3 ± 6.5%, p = 0.005) compared to HS (37.0 ± 5.8% and 56.7 ± 8.1%). Serum 7α-C4 and FGF19 levels were not different among all three groups. Fecal primary BA were increased in IBS-D patients compared to HS, including chenodeoxycholic acid which has laxative properties (25.6 ± 8.5% vs 3.5 ± 0.6%, p = 0.005). Bile acid deconjugation activity was decreased in IBS-D (p = 0.0001) and IBS-C (p = 0.003) feces. Abdominal pain was positively correlated with serum (R = 0.635, p < 0.001) and fecal (R = 0.391, p = 0.024) primary BA.

CONCLUSIONS & INFERENCES

Different sera and fecal BA profiles in IBS patients could be secondary to dysbiosis and further differences between IBS-C and IBS-D could explain stool patterns. This study opens new fields in IBS physiopathology and suggests that modification of BA profiles could have therapeutic potential.

Changes in the modulation of spinal pain processing are related to severity in irritable bowel syndrome

BACKGROUND

In irritable bowel syndrome (IBS) patients can be divided in two groups according to inhibition or facilitation of the RIII nociceptive spinal reflex induced by rectal distension. We further investigated the differences in pain processes in these two groups and their relationship to clinical symptoms.

METHODS

This study included 10 female IBS-C patients with facilitation (Group F) and 10 patients with inhibition (Group I) of the RIII reflex recorded on the left lower limb during slow-ramp rectal distension, and 11 healthy female volunteers. Diffuse noxious inhibitory control (DNIC)-induced inhibition was assessed by measuring the effects of noxious cold stimulation of the right hand on the RIII reflex and the concomitant sensation of pain. Functional magnetic resonance imaging (fMRI) was performed to compare the changes in brain activity induced by painful and non painful rectal distension. Irritable bowel syndrome symptom severity, mood, anxiety, and catastrophizing were also systematically assessed.

KEY RESULTS

Unlike the patients of Group I and healthy volunteers, Group F patients displayed no inhibition of the RIII reflex or of concomitant pain sensation during immersion of the hand in ice-cold water. The reduction of the inhibition induced by heterotopic noxious stimuli was directly correlated with the severity of IBS symptoms, but not with psychological symptoms. The fMRI study showed that non-painful and painful rectal distension induced similar changes in brain activity in the two groups of patients.

CONCLUSION & INFERENCES

Alterations of the modulation of spinal pain processing in IBS correlates with symptom severity but not with psychological factors or brain activity.

Prognostic yield of esophageal manometry in chronic intestinal pseudo-obstruction: a retrospective cohort of 116 adult patients

BACKGROUND

Chronic intestinal pseudo-obstruction (CIPO) refers to a wide and heterogeneous group of neuromuscular disorders, which classically involve the small intestine. However, further investigation is required to determine if motility disturbances involve all parts of the gastrointestinal (GI) tract.

METHODS

Medical records and follow-up examinations of 116 adult CIPO patients [70F, median age 28 (0-79) years] were reviewed and performed at our institution since 1980. Manometry (esophageal, small bowel and anorectal) and gastric emptying scintigraphy reports were retrieved and analyzed. Survival, home parenteral nutrition requirement, and the inability to maintain sufficient oral feeding was analyzed using univariate and multivariate analysis.

KEY RESULTS

The median follow-up time was 6 (0.1-30) years. In all, 90% of patients who underwent at least one motility test, with the exception of small bowel manometry, exhibited at least one abnormal pattern. Esophageal manometry was abnormal in 73% of the cases, including 51% with severe ineffective esophageal motility. Anorectal manometry was abnormal in 59% of the cases, including only 17% with severe abnormalities. Gastric emptying was abnormal in 61% of the cases. Only esophageal motor disorders had significant predicting values for survival, home parenteral nutrition requirement, and an inability to maintain sufficient oral feeding.

CONCLUSIONS & INFERENCES

Our study showed that CIPO was associated with a diffuse involvement of all parts of the GI tract and was not restricted to the small intestine in 90% of the cases studied. Esophageal manometry had a significant prognostic yield and should be systematically performed in CIPO patients.

Increase in fecal primary bile acids and dysbiosis in patients with diarrhea-predominant irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a multifactorial disease for which a dysbiosis of the gut microbiota has been described. Bile acids (BA) could play a role as they are endogenous laxatives and are metabolized by gut microbiota. We compared fecal BA profiles and microbiota in healthy subjects (HS) and patients with diarrhea-predominant IBS (IBS-D), and we searched for an association with symptoms.

METHODS

Clinical features and stool samples were collected in IBS-D patients and HS. Fecal BA profiles were generated using HPLC coupled to tandem mass spectrometry. The fecal microbiota composition was assessed by q-PCR targeting dominant bacterial groups and species implicated in BA transformation.

KEY RESULTS

Fourteen IBS-D patients and 18 HS were included. The two groups were comparable in terms of age and sex. The percentage of fecal primary BA was significantly higher in IBS-D patients than in HS, and it was significantly correlated with stool consistency and frequency. Fecal counts of all bacteria, lactobacillus, coccoides, leptum and Faecalibacterium prausnitzii were similar. There was a significant increase of Escherichia coli and a significant decrease of leptum and bifidobacterium in IBS-D patients.

CONCLUSIONS & INFERENCES

We report an increase of primary BA in the feces of IBS-D patients compared to HS, correlated with stool consistency and frequency. A dysbiosis of different bacterial groups was detected, some of them involved in BA transformation. As the gut microbiota is the exclusive pathway to transform primary into secondary BA, this suggests a functional consequence of dysbiosis, leading to lower BA transformation.

[Fissure syndrome of a gastrointestinal artery pseudoaneurysm in contact with a pseudocyst of the pancreas: rare, but serious complication of chronic pancreatitis]

Most pseudoaneurysms (PsA) of the peripancreatic arteries cause direct erosion of the arterial wall from pancreatic enzymes that are usually in contact with or in a pseudocyst (PC). Rupturing is a rare and serious complication (90% mortality if untreated). We report the case of a 56-year-old patient with chronic alcoholic pancreatitis who developed a cephaloisthmic PC, complicated with a PsA of the gastroduodenal artery revealed by pain and deglobulization associated with cholestasis. After a diagnostic scan, emergency selective arteriography with coil embolization was performed. Five days later, hemorrhage recurred and a cephalic duodenopancreatectomy was performed. PsA of the gastroduodenal artery occur in the first 10 years of chronic pancreatitis. They are revealed by abdominal pains and/or gastrointestinal hemorrhage or shock from rupture. A scan with arterial reconstruction provides diagnosis. Arteriography is the most sensitive technique to locate the aneurysm and its branches and to perform selective embolization with coils. The failure rate is between 0 and 23%. Surgical treatment (elective ligation of the artery or partial pancreatic excision) should be limited to when embolisation fails and/or recurrent hemorrhage.

Advanced gastric cancer with or without peritoneal carcinomatosis treated with hyperthermic intraperitoneal chemotherapy: a single western center experience

INTRODUCTION

The aim of this article was to evaluate the role of hyperthermic intraperitoneal chemotherapy (HIPEC), associated or not to cytoreductive surgery (CS) in the treatment of different stages of advanced gastric cancer (AGC).

PATIENTS AND METHODS

Thirty seven patients with AGC who underwent 43 HIPEC from June 1992 to February 2007 were included. HIPEC used Mitomycin-C and Cisplatin for 60-90 min at 41-43 degrees C intra-abdominal temperature. The main endpoints were long-term survivals, morbidity and mortality rates.

RESULTS

Eleven patients had no demonstrable sign of PC and constituted the Prophylactic-group, while 26 patients had macroscopic PC (PC-group). Five patients were Gilly 1 or 2 (nodules <0.5 cm) and 21 Gilly 3 or 4 (nodules >or=0.5 cm). In the PC-group a complete curative CS was achieved before HIPEC in 8 (PC-curative subgroup) and a palliative HIPEC in 18 patients (PC-palliative subgroup). The overall 30-days mortality was 5% (2 patients). Two patients in the Prophylactic group died within 6 months after hospital discharge (overall mortality 11%). The estimated risk of death per procedure was 9%. Ten patients (27%) presented one or more complications. The median survival was 23.4 months in the Prophylactic group, and 6.6 months in the PC-group (p<0.05). The median survival in the PC-curative subgroup was 15 vs 3.9 months in the PC-palliative subgroup (p=0.007). The median survival according to Gilly classification was significantly different (Gilly 1&2 vs Gilly 3&4, 15 vs 4 months respectively, p=0.014). The global recurrence rates between the Prophylactic group and the PC-curative subgroup at 2years were 36% vs 50% respectively. The median delay to recurrence was 18.5 vs 9.7 months respectively.

CONCLUSION

HIPEC might be useful to improve the survival in selected patients with ACG only when a complete cytoreduction can be achieved. Despite encouraging data, prospective studies, based on larger cohorts of patients are required to assess the role of this procedure as a prophylactic treatment in patients with AGC.

Amantadine for chronic hepatitis C: pilot study in 14 patients

BACKGROUND

Amantadine, a widely available antiviral drug, has been previously reported to be effective in patients with chronic hepatitis C who failed to respond to interferon-alpha therapy. Nevertheless, its efficacy has not been fully studied, particularly in naive patients.

OBJECTIVE AND DESIGN

We conducted a pilot study to determine the efficacy and the safety of amantadine as initial therapy in patients with chronic hepatitis C.

METHODS AND PARTICIPANTS

Fourteen consecutive patients (mean age, 40 years; M/F ratio, 9/5) with chronic hepatitis C, elevated alanine aminotransferase (ALT) and without cirrhosis were treated with a 6-month course of amantadine, 100 mg orally twice daily. Main outcome measures were ALT concentrations and serum hepatitis C virus-RNA (HCV-RNA) levels at the end of therapy.

RESULTS

All adverse events were mild or moderate and were not treatment limiting. At the end of treatment, all patients had detectable serum HCV-RNA and only one patient had a normal ALT level. The serum HCV-RNA median level and the ALT median level were not significantly different at the end of treatment as compared to baseline levels.

CONCLUSIONS

Our results show that amantadine alone cannot be recommended as an alternative therapy in patients with chronic hepatitis C.

[Bronchogenic cyst of the right hemidiaphragm mimicking a hydatic cyst of the liver]

Ectopic subdiaphragmatic development of a bronchogenic cyst is rare. We report the case of a 28-year-old woman with a symptomatic bronchogenic cyst of the right hemidiaphragm simulating a hydatic cyst of the liver on ultrasonography and CT scan. Diagnosis of a diaphragmatic lesion was made during laparotomy, and complete resection was successful. Final diagnosis was done on pathology.

Regional effects of cholecystokinin octapeptide on colonic phasic and tonic motility in healthy humans

The aim of this study was to assess in nine healthy subjects the effects of CCK octapeptide (CCK-8) on colonic tonic activity, measured by a barostat, and phasic activity, measured by manometry. On 2 consecutive days, recordings were performed in the unprepared proximal and distal colons during intravenous infusion of saline and CCK-8 at 5, 20, and 40 ng. kg-1. h-1. In the proximal colon CCK-8 induced, at the 20 and 40 ng. kg-1. h-1 doses, a tonic relaxation with an increase in barostat bag volume to 156 +/- 25 and 157 +/- 19% of basal (P < 0.01) and a decrease in phasic activity to 72 +/- 7 and 76 +/- 7% of basal (P < 0.01). In the distal colon, CCK-8 induced, at the 20 and 40 ng. kg-1. h-1 doses, a tonic relaxation (increase in intrabag volume to 133 +/- 12 and 149 +/- 15%, respectively; P < 0.01), whereas phasic activity increased (128 +/- 8 and 132 +/- 6%, respectively; P < 0.01). Effects of CCK-8 on tonic and phasic activities are different according to the colonic segment. Because meals induce colonic tonic contraction, our results suggest that CCK, as a hormone, is not an important mediator of the response of the colon to feeding in humans.

Tonic and phasic motor activity in the proximal and distal colon of healthy humans

In healthy humans, meals stimulate phasic and tonic motor activity in the unprepared distal colon. The response of the proximal colon remains unknown. In this study, we assessed the effect of a liquid meal on proximal and distal colonic motor activity. In 12 healthy volunteers, colonic tone and phasic motility were simultaneously recorded by using an electronic barostat and perfused catheters in the fasting state and in response to a 1,000-kcal meal. The meal significantly increased the phasic activity in the distal colon (230 +/- 46% of the basal value; P = 0.02) but not in the proximal colon (138 +/- 25% of the basal value; P = 0.2). The intrabag volume of the barostat was significantly more reduced in the distal than in the proximal colon (74 +/- 11 vs. 50 +/- 9% of the basal values, respectively; P = 0.04). We conclude that the postprandial response of the unprepared proximal colon is an immediate tonic contraction that is less pronounced than in the distal colon.

Local regulation of ileal tone in healthy humans

We previously showed that a meal induced, in the human terminal ileum, a delayed tonic relaxation, which could be related to the ileal delivery of meal residues and/or endogenous secretions released by a meal. In this study, we assessed the effects of some components of the ileal contents on its motor activity. In six healthy subjects, we studied ileal tonic and phasic motility in response to the infusion into the terminal ileum of different isotonic solutions: saline, glycochenodeoxycholic acid (GDCA), triglycerides, and short-chain fatty acids (SCFA). Tonic activity was not modified by saline, whereas it was significantly decreased by GDCA and triglycerides (maximal increase in intrabag volume 139 +/- 7% and 152 +/- 16%, respectively, P < 0.01), and significantly increased by SCFA (maximal decrease in intrabag volume 72 +/- 4%, P < 0.01). No significant change of phasic activity was evidenced with either solution. We conclude that 1) bile acids and triglycerides not absorbed in the more proximal gut could be involved in the ileal relaxation occurring after eating and 2) local stimulation of chemoreceptors is of importance in the regulation of ileal motility.