Digestive Health Research
While progress is being made in our understanding of the gastrointestinal (GI) disorders, important questions remain. For example:
- What causes the disorders?
- Why do certain people get them?
- How do we best treat the conditions?
- How do we prevent the disorders?
- How do we cure them?
Sound medical research is needed to explore these questions. Here we report a sampling of research studies and medical news that provide clues to better understanding GI disorders. Each new advance adds a small piece to the puzzle, making the big picture clearer.
To learn more about medical research, visit our web site at www.giResearch.org.
Topics - Newest Postings Listed First
- Gut Microbes in IBS and Chronic Constipation
- Scientists Create Model Human Stomachs to Study Gastric Diseases
- Key Symptoms in Functional Dyspepsia
- Yoga for Young People with IBS
- Preliminary News on Treatments Reported at the 2014 ACG Meeting
- Structure and Functions of the Gut Microbiome
- Integrated Treatments in IBS
- Nortriptyline Lacks Effectiveness in Idiopathic Gastroparesis
- Surveillance of Barrett's Esophagus Reduces Mortality from Esophageal Cancer
- Dietary Elimination Therapy for Eosinophilic Esophagitis
- Biomarkers May Help Predict Risk for Barrett's Esophagus
- FDA Considers Rifaximin for Treatment of IBS-D
- Symptom Episodes in IBS: Consequences for Treatment Procedure
- Statins May Reduce Risk of Barrett's Esophagus
- 6-Year Safety Report of the LINX System for GERD
- Gene Mutation Identified in IBS
- Different Anatomy in Individuals with GERD
- Newer Serotonin Drugs
- GERD or Functional Dyspepsia?
- Microbiota Transplant for Treatment of C. difficile
- Acid Reflux Therapy
- Naloxegol Indicated for Opioid-Induced Constipation
- Authors Call for Standardization of the Decision to Refer for Anti-Reflux Procedures
- IBS and IBD Similarities
- Probiotics in Constipation and IBS
- Targeting IBS Treatment
- Non-Intestinal Symptoms in Childhood Predict IBS in Adulthood
- Foods that Worsen GI Symptoms
- New Guidance on Treatments for Sphincter of Oddi Dysfunction
- Home Parenteral Nutrition for Infants with Ultra-Short Bowel Syndrome
- Restrictive Eating and Abnormal Gut Function
- Guidance Issued in UK for Amitiza in Treating Chronic Idiopathic Constipation
- Results Positive in Study of Rifaximin Repeat Treatment for IBS-D
- Study Underway to Evaluate new Treatment for GERD
- Prevalence of Fructose Malabsorption in Irritable Bowel Syndrome (IBS)
- Chronic constipation associated with increased risk for colorectal tumors
- Bowel Disease A-To-Z Guide Launched In UK
- DDW-2014 News
November 17, 2014 – Investigators in a systematic review and analysis combining existing randomized controlled studies (meta-analysis) concluded that for some people, probiotics (beneficial microorganisms) effectively benefit irritable bowel syndrome (IBS) symptoms such as abdominal pain, bloating, and gas.
However, it remains unclear which individual species and strains of probiotics are the most beneficial.
More evidence is also required before the role in IBS is known of prebiotics (which promote growth of probiotics) or synbiotics (which combine probiotics and prebiotics). The effectiveness of all three therapies in chronic idiopathic/functional constipation (CIC) is also lacking and uncertain.
Source: Ford AC, et al. Am J Gastroenterol. October 2014.
November 10, 2014 – Using stem cells from adult donors, scientists have been able to grow pea-sized three-dimensional human stomach models under laboratory conditions. These miniature stomachs were developed to model mechanisms of infection by the bacterium Helicobacter pylori, which can cause gastric symptoms including nausea, bloating, and vomiting and can lead to ulcers and stomach cancer in extreme cases.
These models are expected to provide a valuable experimental model for the study of the development, functioning, and diseases of the human stomach.
Source: McCracken KW, et al. Nature. October 2014.
November 6, 2014 – Researchers of a focus group study confirmed that symptoms corresponding to fullness after meals (postprandial) and early fullness (satiation) are the key symptoms for developing a patient reported outcomes (PRO) instrument for meal-related functional dyspepsia (FD)/postprandial distress syndrome (PDS). This information is useful for creating tools used to measure treatment effectiveness.
Under a program called PROMIS (Patient Reported Outcomes Measurement Information System), funded by the National Institutes of Health (NIH), PRO tools for various conditions are being developed which will help design treatment plans for individuals, improve doctor-patient communication, and manage chronic conditions.
Source: Carbone F, et al. Neurogastroenterol Motil. September 2014.
October 30, 2014 – Researchers concluded that therapy for irritable bowel syndrome (IBS) using Iyengar yoga training – 1.5 hour sessions twice weekly for six weeks – is a safe and beneficial compliment to medical care in young people, particularly young adults.
The randomized controlled study involved an initial total of 51 participants including adolescents (ages 14–17) and young adults (ages 18–26) with IBS or recurrent abdominal pain. Physical functioning improved in adolescents, and IBS symptoms, emotional distress, fatigue, and sleep quality improved in young adults.
Iyengar yoga postures are taught in a sequence to address specific problems by teachers who receive training in anatomy, physiology, and safety.
Source: Evans S, et al. J Pediatr Gastroenterol Nutr. August 2014.
October 21, 2014 – In a published article, researchers describe how the understanding of human gut microbiology has undergone a leap forward over the past decade. The composition and function of the microbiome (the microbial gut community, especially bacteria), although stable over long periods, may be influenced by a number of factors including genetics, mode of birth delivery, age, diet, geographic location, and medical treatments.
Changes in the microbiome structure have been linked to inflammatory, functional, and metabolic disorders such as irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and obesity. It remains to be known whether these changes are a contributing factor or a result of the disease.
Source: Panda S, et al. Endocr Metab Immune Disord Drug Targets. July 2014.
October 16, 2014 – In a review of IBS treatment studies, investigators summarized the most widely used complementary and alternative medicine (CAM) approaches that have proven effectiveness and have been endorsed by professional organizations. Examples include specific modalities of hypnotherapy, cognitive behavioral therapy, acupuncture, and yoga.
The reviewers encourage the use of both conventional medicine and CAM approaches by doctors in an integrative setting to provide the best outcome and quality of life to affected individuals.
Source: Grundmann O, Saunjoo LY. World J Gastroenterol. January 2014.
October 16, 2014 – Researchers in a randomized controlled clinical trial concluded that, among patients with idiopathic gastroparesis, the use of the antidepressant nortriptyline compared with placebo for 15 weeks did not result in improvement in overall symptoms. These findings do not support the use of nortriptyline for idiopathic gastroparesis.
Gastroparesis remains a challenging syndrome to manage, with few effective treatments and a lack of rigorously controlled trials. Tricyclic antidepressants are often used to treat refractory symptoms of nausea, vomiting, and abdominal pain despite a lack of evidence from well-designed studies for this use.
Source: Parkman HP, et al. JAMA. December 2013.
October 10, 2014 – Researchers in a large study concluded that monitoring individuals with Barrett's esophagus in an endoscopic surveillance program to watch for signs of abnormal tissue (dysplasia) or cancer was associated with lower tumor stages and reduced esophageal cancer-related mortality than those with Barrett's esophagus who did not participate in surveillance.
The study included 10,000 individuals diagnosed in the Netherlands with cancer of the esophagus. Nearly 800 (8%) of these had been diagnosed with Barrett's esophagus prior to the cancer diagnosis. Barrett's esophagus is one of several factors associated with increased risk of developing esophageal cancer. As with all cancers, early detection is critical to improving treatment outcomes. Learn more about Barrett's esophagus here
Source: Verbeek RE, et al. Am J Gastroenterol. August 2014.
October 6, 2014 – A review of existing data of 31 individuals demonstrated that dietary elimination therapy is a safe and effective treatment in adults with eosinophilic esophagitis (EoE). Individuals underwent either a targeted elimination diet that isolated specific food allergies or a more general 6–food elimination diet. Individuals with EoE most frequently reacted to dairy (44%), eggs (44%), wheat (22%), shellfish (11%), legumes (11%), and nuts (11%).
While both diets were difficult for individuals to stick to, the targeted diet had greater success rates. Oral steroids and diet modification are the only therapies currently available for individuals with EoE.
Source: Wolf WA, et al. Clin Gastroenterol Hepatol. August 2014.
September 22, 2014 – A study of 141 mostly white male veterans concluded that a prediction model based on a risk score of circulating levels of several specific substances in the blood (serum biomarkers) in addition to individual demographic and clinical information (age, sex, race, and waist-to-hip ratio as well as gastroesophageal reflux [GER] frequency and duration and H. pylori status) may help identify persons at risk for Barrett's esophagus more accurately than not including the multi-biomarker risk score.
More research is needed to validate these results in the general population and to see if there are additional biomarkers that can be included to improve the predictive value of this model even further.
Source: Thrift AP, et al. Clin Gastroenterol Hepatol. August 2014.
September 19, 2014 – The supplemental new drug application (sNDA) for rifaximin 550 mg has been accepted for review by the U.S. Food & Drug Administration (FDA). Rifaximin is an antibiotic under investigation for the treatment of irritable bowel syndrome with diarrhea (IBS-D). A decision from the FDA regarding the approval status of the drug is expected by Feb 28, 2015. Learn more
September 18, 2014 – A study involving 185 individuals with irritable bowel syndrome (IBS) found that symptoms, including diarrhea, constipation, and abdominal pain, as well as bloating, tend to occur as episodes, over 2–4 days on average, rather than either sporadically or at regular intervals. Roughly half of individuals experienced a mixture of diarrhea and constipation episodes. Episodes of pain were not consistently relieved by a bowel movement or associated with a change in the frequency or consistency of stool.
Better understanding of the nature of episodic symptoms may help doctors and patients improve treatment regimens.
Source: Palsson OS, et al. Am J Gastroenterol. July 2014.
September 9, 2014 – In a study of veterans, statin use was associated with a reduced risk of Barrett's esophagus. Statins are a class of drugs used to lower cholesterol.
This effect was most pronounced in obese individuals and those with a high waist to hip ratio (WHR). The study population included 303 individuals with Barrett's esophagus and 909 controls without Barrett's esophagus.
Source: Nguyen T, et al. Gastroenterology. August 2014.
September 9, 2014 – A safety analysis recently published for the LINX system magnetic sphincter augmentation device (MSAD) for gastroesophageal reflux disease (GERD) reported a low risk profile with no serious events leading to long-term complications associated with the device.
LINX is a surgically implanted device that works by reinforcing the lower esophageal sphincter (LES).
The first 1,000 individuals who underwent the procedure were reevaluated after 6 years. The analysis concluded that the safety profile for the procedure performed by an experienced surgeon establishes it as a viable option for individuals with uncomplicated GERD who are considering antireflux surgery
Source: Lipham JC, et al. Dis Esophagus. June 2014.
September 5, 2014 – A survey of over 500 individuals confirmed a 2.2% prevalence of a mutation in a gene (SCN5A) in individuals with irritable bowel syndrome (IBS), as reported in an earlier pilot study. The SCN5A gene encodes a mechanism (sodium channels) involved in maintaining normal gastrointestinal (GI) motility.
The role of individual genes in symptom generation and expression in IBS remains largely unknown. Identification of these genes and their effects on the structure and function of the GI tract has the potential to reveal the mechanism of IBS in a subset of individuals with the disorder and shed light on new treatment pathways.
Source: Beyder A, et al. Gastroenterology. June 2014.
September 5, 2014 – A study using magnetic resonance imaging (MRI) of 48 people found that those with mild to moderate gastroesophageal reflux disease (GERD) have several anatomical differences relating to the reflux barrier compared to healthy volunteers.
Primary among them, the angle of the esophagus (food tube) into the stomach was found to be wider in individuals with GERD compared with healthy individuals. This angle is an essential part of the way the body prevents reflux, called the "flap valve" mechanism. Also, the opening from the esophagus to the stomach (the esophagogastric junction), a key defense against the reflux of stomach contents after a large meal, was found to open wider in individuals with GERD. Differences in both of these structures in individuals with GERD are suspected to contribute to reflux.
Source: Curcic J, et al. Am J Gastroenterol. May 2014.
August 13, 2014 – Researchers are finding new serotonin drugs that may help treat a variety of functional gastrointestinal (GI) disorders with improved safety.
A new generation of 5-HT4 receptor agonists is useful in treating symptoms of functional constipation, and have an improved safety profile compared to older drugs in this class.
A relatively new serotonin drug to treat irritable bowel syndrome with diarrhea (IBS-D) is also being developed. The drug, ramosetron (a 5HT3 receptor antagonist), has been associated with improved stool consistency in nearly 300 men with IBS-D in Japan. It appears to have an improved safety profile compared to other drugs in this class.
Source: Camilleri M. Neurogastroenterol Motil. August 2014.
August 13, 2014 – In a review of records, researchers at Mayo Clinic found an increase over a two decade period in gastroesophageal reflux disease (GERD) diagnosis rates, but no increase in reported GERD symptoms. About 6 out of 10 persons reporting GERD symptoms received a GERD diagnosis while only about 1 out of 10 persons reporting functional dyspepsia (FD) symptoms received an FD diagnosis.
Common symptoms of GERD – heartburn and/or acid regurgitation – are also reported in about one-third of people with FD. However, treatments differ for these 2 conditions and PPIs that treat GERD do not work for FD.
Source: Pleyer C, et al. Neurogastroenterol Motil. August 2014.
August 12, 2014 – A study involving existing medical information collected on 75 adults and 5 children from 16 different medical centers concluded that fecal microbiota transplant (FMT) appears to be safe and effective for treating C. difficile infection in people who have weakened immune systems.
Up to 15–20% of cases of antibiotic-associated recurrent diarrhea and colitis presented in hospitals are attributed to C. difficile infection. FMT helps restore the balance of beneficial microorganisms lost to antibiotic use, and is indicated for people who have not been helped by standard therapies for C. difficile. However, the use of this treatment among individuals with weakened immune systems has been limited due to concerns about safety.
Source: Kelly CR, et al. Am J Gastroenterol. July 2014.
August 12, 2014 – Proton pump inhibitors (PPIs) reduce stomach acid production and are widely used to treat gastroesophageal reflux disease (GERD). However, in about 30% of patients PPIs do not adequately resolve symptoms.
Researchers looking at the occurrence of acid reflux events concluded that strategies which target the pool of acid (called the acid pocket) that floats on the top of ingested food after a meal may be effective for people with GERD who are not helped by PPIs alone.
Altering the size, position, and acidity of the acid pocket while using a PPI may add therapeutic benefit.
Source: Rohof WO, et al. Clin Gastroenterol Hepatol. July 2014.
August 11, 2014 – In two large phase 3 studies, the drug naloxegol was assessed for safety and efficacy in the treatment of opioid-induced constipation in individuals taking opioids for non-cancer related pain. At daily doses of both 12.5 mg and 25 mg the drug was associated with a significant reduction in constipation symptoms. Side effects were more frequent at higher doses and most often included gastrointestinal (GI) effects (abdominal pain, diarrhea, nausea, and vomiting).
Naloxegol is a member of an emerging class of drugs (peripherally acting µ-opioid receptor antagonists) that decrease the GI side effects of opioids without reducing their painkilling effects. Naloxegol is indicated for use by individuals suffering from opioid-induced constipation who have not responded satisfactorily to standard laxative therapy.
Source: Chey WD, et al. New Engl J Med. June 2014.
August 11, 2014 – No current standards exist regarding decisions by medical professionals to refer children with severe gastroesophageal reflux disease (GERD) for anti-reflux procedures, including surgery. Decisions may be greatly influenced by parental and referring physician opinions. Standardization based on data showing the safety and effectiveness of treatments is recommended by the authors.
Source: Papic JC, et al. Surgery. May 2014.
August 8, 2014 – A review of existing studies of inflammatory bowel disease (IBD) and of irritable bowel syndrome (IBS) found a number of shared factors contributing to both disorders. In some instances these shared factors may involve brain-gut dysfunction, genetics, abnormal microbiota, low-grade inflammation in some IBS patients, and IBS symptoms in some patients with IBD in remission.
Source: Barbara G, et al. Curr Opin Gastroenterol. 2014 May 7.
August 8, 2014 – A review of existing randomized controlled studies aimed to summarize the usefulness of probiotics in health and disease. The researchers concluded that certain strains or combinations may be of benefit in managing constipation and in improving irritable bowel syndrome (IBS) symptoms, among other things. The summary is intended to provide a guide to healthcare providers working with patients.
Source: Taibi A, Comelli EM. Appl Physiol Nutr Metab. 2014 May.
August 8, 2014 – Researchers reviewing existing studies found an imbalance of certain cells (cytokines) involved in regulating inflammation and sensitization in people with irritable bowel syndrome (IBS) compared to people without IBS. Using a cytokine profile may eventually be one way to help individualize treatment for people with IBS.
Source: Bashashati M, et al. Neurogastroenterol Motil. 2014 May 5.
August 8, 2014 – Recent findings suggest that symptoms existing outside the intestinal tract, such as reflux, joint pain, skin abnormalities, and psychological dysfunction, in association with childhood functional abdominal pain are significant predictors of the development of functional gastrointestinal disorders, particularly irritable bowel syndrome (IBS), in adulthood.
Source: Horst S, et al. Clin Castroenterol Hepatol. 2014 Apr 13.
August 8, 2014 – A study of 25 children with functional gastrointestinal (GI) disorders revealed that specific foods are perceived by children to worsen their GI symptoms. These most often included spicy foods, cow’s milk, and pizza. Common coping strategies identified were consuming smaller portions, modifying foods, and avoiding problem foods.
Source: Carlson M, et al. J Acad Nutr Diet. 2014 March.
August 8, 2014 – Results of a new study indicate that ERCP and surgery (sphincterotomy) are not reliably effective treatments of pain resulting from sphincter of Oddi dysfunction (SOD). Because these procedures carry substantial risk, the authors do not recommend the continued use of ERCP and sphincterotomy for abdominal pain following cholecystectomy – removal of the gallbladder.
SOD describes a condition in which the sphincter does not relax at the appropriate time, most often due to scarring or muscle spasm. The back-up of digestive juices that results can cause episodes of severe abdominal pain.
Source: Cotton PB, et al. JAMA. May 2014.
August 8, 2014 – Because of the long-term complications associated with intestinal transplantation, the authors in a new study for the treatment of infants with ultra-short bowel syndrome (U-SBS) recommend a non-transplant home parenteral nutrition approach (in the absence of liver disease).
Parenteral nutrition is an intravenous feeding technique that delivers nutrition directly into the blood stream.
Source: Diamanti A, et al. J Ped Gastroenterol Nutr. April 2014.
August 8, 2014 – Results from a preliminary study of adolescents with irritable bowel syndrome (IBS) suggest that frequent bouts of restrictive eating – such as not eating when hungry or eliminating certain foods – are associated with abnormalities in gastric sensation and gut motility. These gastrointestinal symptoms have been noted in association with other conditions characterized by restrictive eating. Results of this study warrant further investigation.
Source: Van Tilburg MAL, et al. J Ped Gastroenterol Nutr. April 2014.
July 23, 2014 – The National Institute for Health and Care Excellence (NICE) has issued guidance on the use of lubiprostone (Amitiza) for treating chronic idiopathic constipation in the United Kingdom. The guidelines stipulate that the drug should only be considered in adults who have tried at least 2 laxatives at the highest tolerated recommended doses for at least 6 months, but who have not seen an improvement in their symptoms.
NICE clinical guidelines are recommendations on the appropriate treatment and care of people with specific diseases and conditions within the National Health Service (NHS) in the UK.
July 1, 2014 – Salix Pharmaceuticals reported positive results from the TARGET 3 – Phase 3 study to evaluate the efficacy and safety of repeat 14 day treatment with rifaximin for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in people who responded to an initial 14 day treatment course with rifaximin. Compared to placebo, subjects treated with rifaximin showed statistically significant improvement in IBS-related abdominal pain and stool consistency during the 4 week treatment-free follow-up period in the double blind repeat treatment phase.
June 30, 2014 – A phase 2 study is underway on a new drug to treat gastroesophageal reflux disease (GERD) in patients not adequately helped by proton pump inhibitors (PPIs). The study will assess the effect of the drug (IW-3718) compared to placebo as an added treatment in GERD patients who will continue to also take a once-daily PPI. Ironwood Pharmaceuticals is developing the drug.
May 28, 2014 – Fructose can trigger or worsen symptoms in irritable bowel syndrome (IBS). A new study investigated the prevalence of symptomatic fructose malabsorption in those with IBS and tested whether any patient characteristics can help to detect fructose malabsorption.
After ingesting 25g of fructose, fructose malabsorption was found in 22% of those studied. Symptoms indicating intolerance to fructose were found in 28% of sampled individuals, not all of whom demonstrated malabsorption. There were no differences in IBS subtype or clinical symptoms between those who did or did not have malabsorption. However, young males had a greater incidence of malabsorption.
The authors recommend further studies to determine whether a low-fructose diet would help IBS patients who are intolerant to fructose, with and without malabsorption.
May 20, 2014 – A retrospective database study of existing records has found that people with diagnoses of severe chronic constipation (CC) have a potentially higher risk of developing colorectal cancer and non-cancerous (benign) colorectal tumors over time, compared to people without CC.
The study, which looked at medical record databases, reviewed data from over 100,000 patients (28,854 patients with CC and 86,562 without) for 2–5 years. In those with CC, 2.7% developed colorectal cancer vs. 1.7% of those without. For non-cancerous colorectal tumors, the proportion was 24.8% for those with CC and 11.9% for those without. The risks increased with the severity of the chronic constipation.
These findings demonstrate an association only – not a causation – between chronic constipation and the development of colorectal cancer and/or benign tumor. While further studies are needed to determine whether there is an underlying causal link, the authors recommend that doctors be aware of this potential association in order to monitor and treat their patients appropriately.
May 09, 2014 – The Association of Coloproctology of Great Britain and Ireland has launched a guide on their website to help patients find expert surgeons. The guide classifies surgeons by location as well as by their interest a large variety of different bowel conditions.
UK residents who need surgery as part of their treatment can use the guide to find a surgeon who specializes in their condition.
The guide can be found here: http://www.acpgbi.org.uk/specialists/