Probiotics and prebiotics are microbiota-management tools for improving host health. They target gastrointestinal effects via the gut, although direct application to other sites such as the oral ...cavity, vaginal tract and skin is being explored. Here, we describe gut-derived effects in humans. In the past decade, research on the gut microbiome has rapidly accumulated and has been accompanied by increased interest in probiotics and prebiotics as a means to modulate the gut microbiota. Given the importance of these approaches for public health, it is timely to reiterate factual and supporting information on their clinical application and use. In this Review, we discuss scientific evidence on probiotics and prebiotics, including mechanistic insights into health effects. Strains of Lactobacillus, Bifidobacterium and Saccharomyces have a long history of safe and effective use as probiotics, but Roseburia spp., Akkermansia spp., Propionibacterium spp. and Faecalibacterium spp. show promise for the future. For prebiotics, glucans and fructans are well proven, and evidence is building on the prebiotic effects of other substances (for example, oligomers of mannose, glucose, xylose, pectin, starches, human milk and polyphenols).
Small intestinal bacterial overgrowth (SIBO) has been implicated in symptoms associated with functional gastrointestinal disorders (FGIDs), though mechanisms remain poorly defined and treatment ...involves non-specific antibiotics. Here we show that SIBO based on duodenal aspirate culture reflects an overgrowth of anaerobes, does not correspond with patient symptoms, and may be a result of dietary preferences. Small intestinal microbial composition, on the other hand, is significantly altered in symptomatic patients and does not correspond with aspirate culture results. In a pilot interventional study we found that switching from a high fiber diet to a low fiber, high simple sugar diet triggered FGID-related symptoms and decreased small intestinal microbial diversity while increasing small intestinal permeability. Our findings demonstrate that characterizing small intestinal microbiomes in patients with gastrointestinal symptoms may allow a more targeted antibacterial or a diet-based approach to treatment.
Communication between the brain and gut is not one-way, but a bidirectional highway whereby reciprocal signals between the two organ systems are exchanged to coordinate function. The messengers of ...this complex dialogue include neural, metabolic, endocrine and immune mediators responsive to diverse environmental cues, including nutrients and components of the intestinal microbiota (microbiota-gut-brain axis). We are now starting to understand how perturbation of these systems affects transition between health and disease. The pathological repercussions of disordered gut-brain dialogue are probably especially pertinent in functional gastrointestinal diseases, including IBS and functional dyspepsia. New insights into these pathways might lead to novel treatment strategies in these common gastrointestinal diseases. In this Review, we consider the role of the immune system as the gatekeeper and master regulator of brain-gut and gut-brain communications. Although adaptive immunity (T cells in particular) participates in this process, there is an emerging role for cells of the innate immune compartment (including innate lymphoid cells and cells of the mononuclear phagocyte system). We will also consider how these key immune cells interact with the specific components of the enteric and central nervous systems, and rapidly respond to environmental variables, including the microbiota, to alter gut homeostasis.
The gut-brain axis plays an important role in maintaining homeostasis. Many intrinsic and extrinsic factors influence signaling along this axis, modulating the function of both the enteric and ...central nervous systems. More recently the role of the microbiome as an important factor in modulating gut-brain signaling has emerged and the concept of a microbiota-gut-brain axis has been established. In this review, we highlight the role of this axis in modulating enteric and central nervous system function and how this may impact disorders such as irritable bowel syndrome and disorders of mood and affect. We examine the overlapping biological constructs that underpin these disorders with a special emphasis on the neurotransmitter serotonin, which plays a key role in both the gastrointestinal tract and in the brain. Overall, it is clear that although animal studies have shown much promise, more progress is necessary before these findings can be translated for diagnostic and therapeutic benefit in patient populations.
Estimates of disease burden can inform national health priorities for research, clinical care, and policy. We aimed to estimate health care use and spending among gastrointestinal (GI) (including ...luminal, liver, and pancreatic) diseases in the United States.
We estimated health care use and spending based on the most currently available administrative claims from commercial and Medicare Supplemental plans, data from the GI Quality Improvement Consortium Registry, and national databases.
In 2015, annual health care expenditures for gastrointestinal diseases totaled $135.9 billion. Hepatitis ($23.3 billion), esophageal disorders ($18.1 billion), biliary tract disease ($10.3 billion), abdominal pain ($10.2 billion), and inflammatory bowel disease ($7.2 billion) were the most expensive. Yearly, there were more than 54.4 million ambulatory visits with a primary diagnosis for a GI disease, 3.0 million hospital admissions, and 540,500 all-cause 30-day readmissions. There were 266,600 new cases of GI cancers diagnosed and 144,300 cancer deaths. Each year, there were 97,700 deaths from non-malignant GI diseases. An estimated 11.0 million colonoscopies, 6.1 million upper endoscopies, 313,000 flexible sigmoidoscopies, 178,400 upper endoscopic ultrasound examinations, and 169,500 endoscopic retrograde cholangiopancreatography procedures were performed annually. Among average-risk persons aged 50–75 years who underwent colonoscopy, 34.6% had 1 or more adenomatous polyps, 4.7% had 1 or more advanced adenomatous polyps, and 5.7% had 1 or more serrated polyps removed.
GI diseases contribute substantially to health care use in the United States. Total expenditures for GI diseases are $135.9 billion annually—greater than for other common diseases. Expenditures are likely to continue increasing.
Reactive oxygen species (ROS) are generated as by-products of normal cellular metabolic activities. Superoxide dismutase, glutathione peroxidase, and catalase are the enzymes involved in protecting ...cells from the damaging effects of ROS. ROS are produced in response to ultraviolet radiation, cigarette smoking, alcohol, nonsteroidal anti-inflammatory drugs, ischemia-reperfusion injury, chronic infections, and inflammatory disorders. Disruption of normal cellular homeostasis by redox signaling may result in cardiovascular, neurodegenerative diseases and cancer. ROS are produced within the gastrointestinal (GI) tract, but their roles in pathophysiology and disease pathogenesis have not been well studied. Despite the protective barrier provided by the mucosa, ingested materials and microbial pathogens can induce oxidative injury and GI inflammatory responses involving the epithelium and immune/inflammatory cells. The pathogenesis of various GI diseases including peptic ulcers, gastrointestinal cancers, and inflammatory bowel disease is in part due to oxidative stress. Unraveling the signaling events initiated at the cellular level by oxidative free radicals as well as the physiological responses to such stress is important to better understand disease pathogenesis and to develop new therapies to manage a variety of conditions for which current therapies are not always sufficient.
Multiple gastrointestinal (GI) symptoms, including diarrhea, nausea/vomiting, and abdominal pain, as well as liver enzyme abnormalities, have been variably reported in patients with coronavirus ...disease 2019 (COVID-19). This document provides best practice statements and recommendations for consultative management based on a systematic review and meta-analysis of international data on GI and liver manifestations of COVID-19.
We performed a systematic literature search to identify published and unpublished studies using OVID Medline and preprint servers (medRxiv, LitCovid, and SSRN) up until April 5, 2020; major journal sites were monitored for US publications until April 19, 2020. We pooled the prevalence of diarrhea, nausea, vomiting, and abdominal pain, as well as liver function tests abnormalities, using a fixed-effect model and assessed the certainty of evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework.
We identified 118 studies and used a hierarchal study selection process to identify unique cohorts. We performed a meta-analysis of 47 studies including 10,890 unique patients. Pooled prevalence estimates of GI symptoms were as follows: diarrhea 7.7% (95% confidence interval CI, 7.2%–8.2%), nausea/vomiting 7.8% (95% CI, 7.1%–8.5%), and abdominal pain 2.7% (95% CI, 2.0%–3.4%). Most studies reported on hospitalized patients. The pooled prevalence estimates of elevated liver abnormalities were as follows: aspartate transaminase 15.0% (95% CI, 13.6%–16.5%) and alanine transaminase 15.0% (95% CI, 13.6%–16.4%). When we compared studies from China to studies from other countries in subgroup analyses, diarrhea, nausea/vomiting, and liver abnormalities were more prevalent outside of China, with diarrhea reported in 18.3% (95% CI, 16.6%–20.1%). Isolated GI symptoms were reported rarely. We also summarized the Gl and liver adverse effects of the most commonly utilized medications for COVID-19.
GI symptoms are associated with COVID-19 in <10% of patients. In studies outside of China, estimates are higher. Further studies are needed with standardized GI symptoms questionnaires and liver function test checks on admission to better quantify and qualify the association of these symptoms with COVID-19. Based on findings from our meta-analysis, we provide several Best Practice Statements for the consultative management of COVID-19.
The prevalence and prognosis of digestive system involvement, including gastrointestinal symptoms and liver injury, in patients with COVID-19 remains largely unknown. We aimed to quantify the effects ...of COVID-19 on the digestive system.
In this systematic review and meta-analysis, we systematically searched PubMed, Embase, and Web of Science for studies published between Jan 1, 2020, and April 4, 2020. The websites of WHO, CDC, and major journals were also searched. We included studies that reported the epidemiological and clinical features of COVID-19 and the prevalence of gastrointestinal findings in infected patients, and excluded preprints, duplicate publications, reviews, editorials, single case reports, studies pertaining to other coronavirus-related illnesses, and small case series (<10 cases). Extracted data included author; date; study design; country; patient demographics; number of participants in severe and non-severe disease groups; prevalence of clinical gastrointestinal symptoms such as vomiting, nausea, diarrhoea, loss of appetite, abdominal pain, and belching; and digestive system comorbidities including liver disease and gastrointestinal diseases. Raw data from studies were pooled to determine effect estimates.
We analysed findings from 35 studies, including 6686 patients with COVID-19, that met inclusion criteria. 29 studies (n=6064) reported gastrointestinal symptoms in patients with COVID-19 at diagnosis, and the pooled prevalence of digestive system comorbidities was 4% (95% CI 2-5; range 0-15; I
=74%). The pooled prevalence of digestive symptoms was 15% (10-21; range: 2-57; I
=96%) with nausea or vomiting, diarrhoea, and loss of appetite being the three most common symptoms. The pooled prevalence of abnormal liver functions (12 studies, n=1267) was 19% (9-32; range 1-53; I
=96%). Subgroup analysis showed patients with severe COVID-19 had higher rates of abdominal pain (odds ratio OR 7·10 95% CI 1·93-26·07; p=0·003; I
=0%) and abnormal liver function including increased ALT (1·89 1·30-2·76; p=0·0009; I
=10%) and increased AST (3·08 2·14-4·42; p<0·00001; I
=0%) compared with those with non-severe disease. Patients in Hubei province, where the initial COVID-19 outbreak occurred, were more likely to present with abnormal liver functions (p<0·0001) compared with those outside of Hubei. Paediatric patients with COVID-19 had a similar prevalence of gastrointestinal symptoms to those of adult patients. 10% (95% CI 4-19; range 3-23; I
=97%) of patients presented with gastrointestinal symptoms alone without respiratory features. Patients who presented with gastrointestinal system involvement had delayed diagnosis (standardised mean difference 2·85 95% CI 0·22-5·48; p=0·030; I
=73%). Patients with gastrointestinal involvement tended to have a poorer disease course (eg, acute respiratory distress syndrome OR 2·96 95% CI 1·17-7·48; p=0·02; I
=0%).
Our study showed that digestive symptoms and liver injury are not uncommon in patients with COVID-19. Increased attention should be paid to the care of this unique group of patients.
None.
Non–IgE-mediated gastrointestinal food-induced allergic disorders (non-IgE-GI-FAs) account for an unknown proportion of food allergies and include food protein–induced enterocolitis syndrome (FPIES), ...food protein–induced allergic proctocolitis (FPIAP), and food protein–induced enteropathy (FPE). Non-IgE-GI-FAs are separate clinical entities but have many overlapping clinical and histologic features among themselves and with eosinophilic gastroenteropathies. Over the past decade, FPIES has emerged as the most actively studied non-IgE-GI-FA, potentially because of acute and distinct clinical features. FPIAP remains among the common causes of rectal bleeding in infants, while classic infantile FPE is rarely diagnosed. The overall most common allergens are cow's milk and soy; in patients with FPIES, rice and oat are also common. The most prominent clinical features of FPIES are repetitive emesis, pallor, and lethargy; chronic FPIES can lead to failure to thrive. FPIAP manifests with bloody stools in well-appearing young breast-fed or formula-fed infants. Features of FPE are nonbloody diarrhea, malabsorption, protein-losing enteropathy, hypoalbuminemia, and failure to thrive. Non-IgE-GI-FAs have a favorable prognosis; the majority resolve by 1 year in patients with FPIAP, 1 to 3 years in patients with FPE, and 1 to 5 years in patients with FPIES, with significant differences regarding specific foods. There is an urgent need to better define the natural history of FPIES and the pathophysiology of non-IgE-GI-FAs to develop biomarkers and novel therapies.
PDF
