Ageing and the gut

An accurate aging clock developed from large-scale gut microbiome and human gene expression data

Accurate measurement of the biological markers of the aging process could provide an "aging clock" measuring predicted longevity and enable the quantification of the effects of specific lifestyle choices on healthy aging. Using machine learning techniques, we demonstrate that chronological age can be predicted accurately from (1) the expression level of human genes in capillary blood and (2) the expression level of microbial genes in stool samples. The latter uses a very large metatranscriptomic dataset, stool samples from 90,303 individuals, which arguably results in a higher quality microbiome-aging model than prior work. Our analysis suggests associations between biological age and lifestyle/health factors, e.g., people on a paleo diet or with IBS tend to have higher model-predicted ages and people on a vegetarian diet tend to have lower model-predicted ages. We delineate the key pathways of systems-level biological decline based on the age-specific features of our model.

Development and validation of a nomogram for predicting gram-negative bacterial infections in patients with peritoneal dialysis-associated peritonitis

Background

This study aimed to develop a nomogram for predicting gram-negative bacterial (GNB) infections in patients with peritoneal dialysis-associated peritonitis (PDAP) to identify patients at high risk for GNB infections.

Methods

In this investigation, hospitalization information was gathered retrospectively for patients with PDAP from January 2016 to December 2021. The concatenation of potential biomarkers obtained by univariate logistic regression, LASSO analysis, and RF algorithms into multivariate logistic regression was used to identify confounding factors related to GNB infections, which were then integrated into the nomogram. The concordance index (C-Index) was utilized to assess the precision of the model's predictions. The area under the curve (AUC) and decision curve analysis (DCA) was used to assess the predictive performance and clinical utility of the nomogram.

Results

The final study population included 217 patients with PDAP, and 37 (17.1%) patients had gram-negative bacteria due to dialysate effluent culture. After multivariate logistic regression, age, procalcitonin, and hemoglobin were predictive factors of GNB infections. The C-index and bootstrap-corrected index of the nomogram for estimating GNB infections in patients were 0.821 and 0.814, respectively. The calibration plots showed good agreement between the predictions of the nomogram and the actual observation of GNB infections. The AUC of the receiver operating characteristic curve was 0.821, 95% CI: 0.747-0.896, which indicates that the model has good predictive accuracy. In addition, the DCA curve showed that the nomogram had a high clinical value in the range of 1%-94%, which further demonstrated that the nomogram could accurately predict GNB infection in patients with PDAP.

Conclusions

We have created a new nomogram for predicting GNB infections in patients with PDAP. The nomogram model may improve the identification of GNB infections in patients with PDAP and contribute to timely intervention to improve patient prognosis.

The Aged Intestine: Performance and Rejuvenation

Owing to the growing elderly population, age-related problems are gaining increasing attention from the scientific community. With senescence, the intestine undergoes a spectrum of changes and infirmities that are likely the causes of overall aging. Therefore, identification of the aged intestine and the search for novel strategies to rescue it, are required. Although progress has been made in research on some components of the aged intestine, such as intestinal stem cells, the comprehensive understanding of intestinal aging is still limited, and this restricts the in-depth search for efficient strategies. In this concise review, we discuss several aspects of intestinal aging. More emphasis is placed on the appraisal of current and potential strategies to alleviate intestinal aging, as well as future targets to rejuvenate the aged intestine.

Peritoneal dialysis-related peritonitis caused by gram-negative organisms: ten-years experience in a single center

Objectives

Concerns are increasing about the clinical characteristics of gram- negative bacterial peritonitis for providing reference for clinical diagnosis, treatment and prevention.

Methods

A retrospective analysis was performed examining patients who developed peritoneal dialysis-related peritonitis (PDRP) from 1 January 2009 to 31 December 2018.

Results

Among 898 PD patients, 677 episodes of peritonitis occurred in 344 patients. Over 10 years, the proportion of gram-negative bacterial peritonitis increased from 0% to 26.15% (p = .045). E. coli was the leading cause (38.51%) of the 148 cases of gram-negative bacterial peritonitis. The increase of E. coli peritonitis between the first 5 and the last 5 years was obvious (20.45% vs. 46.15%). The antimicrobial sensitivity of gram-negative organisms to cefotaxime decreased from 71.43% to 55.84% (p = .017). In the gram-negative group, the effluent white cell count (WCC) on the first day was larger (OR: 1.374;95%CI: 1.248–1.563; p < .001), the time required for the WCC to normalize was longer (OR: 1.100;95%CI: 1.037–1.189; p = .003), and the level of C-reactive protein (CRP) was higher (OR: 1.038;95%CI: 1.026–1.042; p < .001) than those in the gram-positive group. The complete cure rate and treatment failure rate of gram-negative bacteria peritonitis were 87.8% and 12.2% respectively.

Conclusions

Over 10 years, the proportion of gram-negative bacterial peritonitis increased, with E. coli epidermidis being the most common pathogen. More effluent WCC on the first day, longer time required for the WCC to normalize, and higher level of CRP are more common for gram-negative bacterial peritonitis. Prognosis of gram-negative bacterial peritonitis is worse.

Comparing Response of Sheep and Cow Milk on Acute Digestive Comfort and Lactose Malabsorption: A Randomized Controlled Trial in Female Dairy Avoiders

Background: Sheep milk (SM) is a possible alternate dairy source for those who experience digestive symptoms with cow milk (CM). While both the milks contain lactose, one of the causes for self-reported intolerance to CM, the composition of SM and CM also differs across proteins and fats, which have been shown to impact digestive processes. Objective: To compare the acute digestive comfort and lactose malabsorption of SM to CM in female dairy avoiders. Method: In a double-blinded, randomized cross over trial, 30 dairy-avoiding females (aged 20-30 years) drank 650 mL of SM or CM (each reconstituted from spray dried powder) following an overnight fast, on two separate occasions at least 1 week apart. Blood samples were collected for glucose and insulin assessment, and single nucleotide polymorphisms of the lactase (LCT) gene (C/T₁₃₉₁₀ and G/A₂₂₀₁₈). Breath H₂ and visual analog scale (VAS) digestive symptom scores were recorded at fasting and regular intervals over 4 h after ingestion. Results: Eighty percentage of study participants were lactase non-persistent (LNP; CC₁₃₉₁₀ and GG₂₂₀₁₈ genotype). Digestive symptoms, including abdominal cramps, distension, rumbling, bloating, belching, diarrhea, flatulence, vomiting, and nausea, were similar in response to SM and CM ingestion (milk × time, P > 0.05). Breath H₂ was greater after CM than SM (72 ± 10 vs. 43 ± 6 ppm at 240 min, P < 0.001), which may be due to greater lactose content in CM (33 vs. 25 g). Accordingly, when corrected for the lactose content breath H₂ did not differ between the two milks. The response remained similar when analyzed in the LNP subset alone (n = 20). Conclusions: Despite a higher energy and nutrient content, SM did not increase adverse digestive symptoms after ingestion, relative to CM, although there was a reduced breath H₂ response, which could be attributed to the lower lactose content in SM. The tolerability of SM should be explored in populations without lactose intolerance for whom underlying trigger for intolerance is unknown.

Common Urinary and Bowel Disorders in the Geriatric Population

The prevalence of urinary incontinence and other lower urinary tract symptoms increases with older age. These symptoms are more noticeable in men after the seventh decade of life and in women after menopause. Constipation and fecal incontinence are major causes of symptoms in elderly patients and can significantly impair quality of life. This article summarizes the current literature regarding the occurrence and implications of lower urinary tract and bowel symptoms in the geriatric population.

New horizons in iron deficiency anaemia in older adults

Iron deficiency anaemia (IDA) is common in older adults and associated with a range of adverse outcomes. Differentiating iron deficiency from other causes of anaemia is important to ensure appropriate investigations and treatment. It is possible to make the diagnosis reliably using simple blood tests. Clinical evaluation and assessment are required to help determine the underlying cause and to initiate appropriate investigations. IDA in men and post-menopausal females is most commonly due to occult gastrointestinal blood loss until proven otherwise, although there is a spectrum of underlying causative pathologies. Investigation decisions should take account of the wishes of the patient and their competing comorbidities, individualising the approach. Management involves supplementation using oral or intravenous (IV) iron then consideration of treatment of the underlying cause of deficiency. Future research areas are outlined including the role of Hepcidin and serum soluble transferrin receptor measurement, quantitative faecal immunochemical testing, alternative dosing regimens and the potential role of IV iron preparations.

Malnutrition in the elderly

Changes that occur naturally throughout the ageing process place the elderly population at greater risk of malnourishment. This review discusses the significance, causes, consequences and assessment of malnutrition in the elderly.

To what extent does sex, age and BMI impact medical and pharmacy costs? A retrospective cohort study involving employees in a large school district in the USA

OBJECTIVE

To identify the extent that sex, age and body mass index (BMI) is associated with medical and pharmacy costs.

DESIGN

Retrospective cohort.

SETTING

A school district in the Western USA involving 2531 workers continuously employed during 2011-2014.

MAIN OUTCOME MEASURES

Medical and pharmacy costs and BMI.

RESULTS

Approximately 84% of employees participated in wellness screening. Participants were 1.03 (95% CI 1.01 to 1.06) times more likely to be women and younger (M=47.8 vs 49.8, p<0.001). Median medical and pharmacy costs were higher for women than men, increased with age, and were greater in morbidly obese individuals (p<0.001). Annual pharmacy claims were 18% more likely to be filed by women than men, 23% more likely filed by those aged ≥60 versus <40 years, and 6% more likely filed by morbidly obese individuals than of normal weight (p<0.001) individuals. Greater medical and pharmacy costs in older age were most pronounced in underweight and morbidly obese groups. Higher use of medication among women than men was primarily because of drugs involving birth control, osteoporosis, thyroid disease and urinary tract infection. Higher medication use in older age was primarily related to medications used to treat gastrointestinal problems. Medication use was positively associated with BMI weight classifications for most of the 33 drug types considered, with exceptions involving birth control, herpes and osteoporosis. A J-shape relationship was observed between BMI and medication use for acne, antibiotic, cold/influenza/allergy, eye infection, oedema, muscle spasms, pain and ulcers.

CONCLUSIONS

Medications associated with higher medical and pharmacy costs among women, older age and underweight or obese individuals are identified. Lowering medical and pharmacy costs requires weight management in older ages, particularly for underweight and obese. Higher pharmacy costs for certain drugs among underweight individuals may be associated with poorer nutrition.

Gastrointestinal Tract Disorders in Older Age

Considering an increase in the life expectancy leading to a rise in the elderly population, it is important to recognize the changes that occur along the process of aging. Gastrointestinal (GI) changes in the elderly are common, and despite some GI disorders being more prevalent in the elderly, there is no GI disease that is limited to this age group. While some changes associated with aging GI system are physiologic, others are pathological and particularly more prevalent among those above age 65 years. This article reviews the most important GI disorders in the elderly that clinicians encounter on a daily basis. We highlight age-related changes of the oral cavity, esophagus, stomach, small and large bowels, and the clinical implications of these changes. We review epidemiology and pathophysiology of common diseases, especially as they relate to clinical manifestation in elderly. Details regarding management of specific disease are discussed in detail if they significantly differ from the management for younger groups or if they are associated with significant challenges due to side effects or polypharmacy. Cancers of GI tract are not included in the scope of this article.

Psychopharmacology and pharmacokinetics

The overall physiologic changes associated with aging lead to changes in both pharmacokinetic and pharmacodynamic actions of many medications. This, in turn, leads to changes in the impact that a wide variety of medications have on older adults when compared to younger, healthy individuals. These pharmacokinetic and pharmacodynamic variations can cause either lesser or greater than expected responses to medication. Knowledge of the physiologic changes that are expected to occur in the elderly can help to identify medications that may require dose adjustments or that should be avoided, due to increased risk in this population. As a general principle, medications should be started at lower doses in the elderly with slow titration schedules to reduce the risk of adverse effects.

Benefit of Capsule Endoscopy in the Setting of Iron Deficiency Anemia in Patients Above Age 65

Background

Iron deficiency anemia (IDA) is a common indication for a capsule endoscopy (CE), which is often offered after a negative bidirectional endoscopy. Since malignancy is a concern in the older population with IDA, upper and lower endoscopic exams are typically performed. If these tests are negative, CE may be offered to evaluate the small intestine. However, choosing the ideal candidates who are most likely to benefit from a CE study is challenging.

Aims

The goal of this study was to assess the outcomes for CE in patients with IDA over age 65 and assess which factors are more likely to contribute to a positive CE yield.

Methods

A retrospective review of all CE studies at St. Paul's Hospital from January 2010 to June 2016 was conducted after ethics approval. Inclusion criteria included the following: age >65, hemoglobin <120 g/L, serum ferritin <70 μg/L, and at least one high-quality complete EGD/colonoscopy performed before CE. Variables to assess factors that are more likely to contribute to a positive capsule yield included use of anticoagulation medications, NSAIDs, PPIs, transfusion burden and cardiac disease. A Chi-Square test was then used to determine clinical predictive factors of a positive and negative study.

Results

There were 1149 CE studies that were reviewed, of which 130 CE studies met inclusion criteria. Fifty-one studies (40.6%) had positive findings, and from this group, 30 (58.8%) recommended active intervention (i.e., EGD, n = 8; colonoscopy, n = 12; push enteroscopy, n = 3; double-balloon [DB] enteroscopy, n = 2; small bowel resection, n = 3; escalation of Crohn's therapy, n = 2), while 21 (41.2%) were managed supportively, typically with iron supplementation. Most negative studies (73 of 79) recommended supportive therapy (other recommendations included hematological workup, n = 3; hiatal hernia repair, n = 1; proton-pump inhibitors [PPI] initiation, n = 1; stop donating blood, n = 1).A history of cardiac disease had a significant association with positive findings (0.54 versus 0.33, P = 0.001). Conversely, a known history of low ferritin levels (0.84 versus 0.68, P = 0.046) and a known history of hiatal hernia (0.25 versus 0.08, P = 0.012) were associated with a negative study.

Conclusions

These findings suggest that the clinical yield of CE in IDA in patients above age 65 is relatively low. The majority of all CE studies recommended supportive therapy or repeat endoscopic exams (EGD/colonoscopy) of areas previously assessed and lesions missed. Provided that initial endoscopic exams were thorough and Crohn's disease management was optimized, the overall rate of changing management significantly was low at five of 130 studies (two DB enteroscopies and three resections) or 3.8%. Clinical factors focusing on cardiac history, ferritin levels and the presence of a hiatal hernia may be of utility to predict benefit of CE. Emphasis on these data may help select more appropriate patients for capsule endoscopy.

Clinical and microbiological characteristics of peritoneal dialysis-related peritonitis caused by Escherichia coli in southern Taiwan

Peritonitis is a serious complication and major cause of treatment failure in patients undergoing peritoneal dialysis (PD). Escherichia coli is the major pathogen in extraintestinal Gram-negative infections, including PD-related peritonitis. The outcomes of E. coli peritonitis in PD varied from relatively favorable outcomes to a higher incidence of treatment failure. The aim of this study was to investigate the impact of bacterial virulence and host characteristics on the outcomes of PD-related peritonitis caused by E. coli. From January 2000 to June 2016, a total of 47 episodes of monomicrobial and 10 episodes of polymicrobial E. coli PD-related peritonitis, as well as 89 episodes of monomicrobial Gram-positive (56 Staphylococcus spp. and 33 Streptococcus spp.) PD-related peritonitis cases, were retrospectively enrolled. Clinical features, E. coli bacterial virulence, and outcomes were analyzed. Compared to Streptococcus spp. peritonitis, E. coli peritonitis had a higher peritoneal catheter removal rate (38 versus 12%; P = 0.0115). Compared to the monomicrobial group, patients in polymicrobial group were older and had higher peritoneal catheter removal rate (80 versus 38%; P = 0.0324). Treatment failure of E. coli peritonitis was associated with more polymicrobial peritonitis and immunocompromised comorbidity, longer duration of PD therapy, and more antimicrobial resistance. E. coli isolates with more iron-related genes had higher prevalence of phylogenetic group B2 and papG II, iha, ompT, and usp genes. This study demonstrates the important roles of clinical and bacterial characteristics in the outcomes of monomicrobial and polymicrobial E. coli PD-related peritonitis.

Vertebrate food products as a potential source of prion-like α-synuclein

The aberrant aggregation of the protein α-synuclein is thought to be involved in Parkinson’s disease (PD). However, the factors that lead to initiation and propagation of α-synuclein aggregation are not clearly understood. Recently, the hypothesis that α-synuclein aggregation spreads via a prion-like mechanism originating in the gut has gained much scientific attention. If α-synuclein spreads via a prion-like mechanism, then an important question becomes, what are the origins of this prion-like species? Here we review the possibility that α-synuclein aggregation could be seeded via the ingestion of a prion-like α-synuclein species contained within food products originating from vertebrates. To do this, we highlight current evidence for the gut-to-brain hypothesis of PD, and put this in context of available routes of α-synuclein prion infectivity via the gastrointestinal (GI) tract. We then discuss meat as a ready exogenous source of α-synuclein and how certain risk factors, including inflammation, may allow for dietary α-synuclein to pass from the GI lumen into the host to induce pathology. Lastly, we review epidemiological evidence that dietary factors may be involved in PD. Overall, research to date has yet to directly test the contribution of dietary α-synuclein to the mechanism of initiation and progression of the disease. However, numerous experimental findings, including the potent seeding and spreading behavior of α-synuclein fibrils, seem to support, at least in part, the feasibility of an infection with a prion α-synuclein particle via the GI tract. Further studies are required to determine whether dietary α-synuclein contributes to seeding pathology in the gut.

Gut bacterial peptides with autoimmunity potential as environmental trigger for late onset complex diseases: In-silico study

Recent evidences suggest that human gut microbiota with major component as bacteria can induce immunity. It is also known that gut lining depletes with ageing and that there is increased risk of autoimmune and inflammatory disorders with ageing. It is therefore likely that both may be correlated as depletion of gut lining exposes the gut bacterial antigens to host immune mechanisms, which may induce immunity to certain bacterial proteins, but at the same time such immunity may also be auto-immunogenic to host. This autoimmunity may make a protein molecule nonfunctional and thereby may be involved in late onset metabolic, autoimmune and inflammatory disorders such as, Diabetes, Rheumatoid Arthritis, Hyperlipidemias and Cancer. In this in-silico study we found a large number of peptides identical between human and gut bacteria which were binding to HLA-II alleles, and hence, likely to be auto-immunogenic. Further we observed that such autoimmune candidates were enriched in bacterial species belonging to Firmicutes and Proteobacteria phyla, which lead us to conclude that these phyla may have higher disease impact in genetically predisposed individuals. Functional annotation of human proteins homologous to candidate gut-bacterial peptides showed significant enrichment in metabolic processes and pathways. Cognitive trait, Ageing, Alzheimer, Type 2 diabetes, Chronic Kidney Failure (CKF), Chronic Obstructive Pulmonary Disease (COPD) and various Cancers were the major diseases represented in the dataset. This dataset provides us with gut bacterial autoimmune candidates which can be studied for their clinical significance in late onset diseases.

Effects of two different glutamine-containing enteral supplements on stool frequency and density in elderly patients recovering from acute critical illness

AIM

Glutamine has various beneficial functions in the gastrointestinal tract. The present study was designed to investigate the effect of two different glutamine supplements on bowel movement at the start of enteral feeding in elderly inpatients.

METHODS

This was a double-blind, prospective, randomized comparison study. A total of 25 patients aged >75 years recovering from a critical illness in a non-intensive care unit and scheduled for tube feeding were recruited. Of them, 22 consenting patients were randomly assigned to two groups: glutamine-fiber-oligosaccharide treatment group (n = 11) and glutamine F treatment group (n = 11). They were given glutamine three times daily at a dosage of 9 g/day. Enteral nutrition was given at the same dosage to both groups for the duration of the study. The end-points were stool frequency, Bristol Scale Form Score, bowel function index (Bristol Scale Form Score × stool frequency), the percentage of patients with stool frequency over three per day and those with a BSFS of 6 or 7 in each group.

RESULTS

There were no significant differences between the two groups in terms of patient characteristics before the study. All the end-points in the glutamine F group were significantly lower than those in the glutamine-fiber-oligosaccharide group.

CONCLUSIONS

Compared with glutamine-fiber-oligosaccharide, glutamine F administration resulted in stool hardening and reduced stool frequency in elderly inpatients recovering from acute critical illness in non-intensive care units. The effects might be caused by the different additive components of glutamine supplements. Geriatr Gerontol Int 2017; 17: 2514-2519.

Increased Intake of Foods with High Nutrient Density Can Help to Break the Intergenerational Cycle of Malnutrition and Obesity

A workshop held at the University Medical Center in Groningen, The Netherlands, aimed at discussing the nutritional situation of the population in general and the role diet plays during critical windows in the life course, during which the body is programmed for the development of non-communicable diseases (NCDs). NCDs are increasingly prevalent as our society ages, and nutrition is well known to play an important role in determining the risk and the time of onset of many common NCDs. Even in affluent countries, people have difficulties to achieve adequate intakes for a range of nutrients: Economic constraints as well as modern lifestyles lead people to consume diets with a positive energy balance, but low in micronutrients, resulting in increasing prevalence of obesity and suboptimal nutritional status. Information about nutrient density, which refers to the content of micronutrients relative to energy in food or diets, can help identify foods that have a low calorie to nutrient ratio. It thus allows the consumption of diets that cover nutritional needs without increasing the risk of becoming obese. Given the impact a nutrient dense, low energy diet can have on health, researchers, food industry and governments jointly should develop options for affordable, appealing nutrient-rich food products, which, in combination with physical activity, allow for optimal health throughout the life-course.

Common GI Drug Interactions in the Elderly

OPINION STATEMENT

The careful review of drug-drug interactions is vital to the safe prescribing of medications for chronic medical conditions. The elderly population suffers from multiple medical problems, and polypharmacy leads to further morbidity in this vulnerable group of patients. We discuss gastrointestinal conditions such as GERD, peptic ulcer disease, gastroparesis, diarrhea, constipation, irritable bowel syndrome, inflammatory bowel disease, chronic liver disease and the commonly used medications in these conditions. Treatment options must be individualized and tailored to accommodate the underlying pharmacokinetics and known drug-drug interactions. The indication for the use of a therapeutic agent in the elderly and the duration of use must be frequently readdressed to help prevent polypharmacy and adverse drug reactions. Medications should be started at a low dose with careful titration to achieve a clinical response to prevent toxicity. The aim of this article is to increase awareness of important drug-drug interactions of commonly prescribed gastrointestinal medications in the elderly.

Dementia and its relationship with food

This article provides an overview of dementia and how it relates to nutrition. It examines the evidence for food and nutrition preventing, causing and treating dementia. The article highlights how malnutrition can affect the individual with dementia. The remainder of the article provides an in-depth, focused discussion on the difficulties people may experience in the community in relation to food and eating and the impact this has on family caregivers, with recommendations for achieving optimum nutrition.

Higher blood glucose level associated with body mass index and gut microbiota in elderly people

Background

Some dominant bacterial divisions of the intestines have been linked to metabolic diseases such as overweight and diabetes.

Objective

A pilot study aimed to evaluate the relations between the culturable intestinal bacteria with body mass index (BMI) and some principal cellular and metabolic markers of blood in people older than 65.

Design

Altogether 38 generally healthy elderly people were recruited: ambulatory (n=19) and orthopedic surgery (n=19). Questionnaires on general health, anthropometric measurements, routine clinical and laboratory data, and quantitative composition of cultivable gut microbiota were performed.

Results

Blood glucose level was positively correlated with BMI (r=0.402; p=0.014). Higher blood glucose level had negative correlation with relative share of intestinal anaerobic bacteria such as bacteroides (r=−0.434; p=0.0076) and gram-positive anaerobic cocci (r=−0.364; p=0.027). In contrast, the relative share of bifidobacteria (r=0.383; p=0.019) and staphylococci (r=0.433; p=0.008) was positively correlated to blood glucose level. In elderly people, a higher blood glucose concentration was predicted by the reduction of the anaerobes’ proportion (adj. sex, age, and BMI R²=0.192, p=0.028) and that of Bacteroides sp. (adj. R²=0.309, p=0.016).

Conclusion

A tight interplay between increased BMI, level of blood glucose, and the reduced proportion of cultivable bacteroides is taking place in the gut microbiota of elderly people.

Variation in gastric pH may determine kiwifruit's effect on functional GI disorder: an in vitro study

Consumption of kiwifruit is reported to relieve symptoms of functional gastrointestinal (GI) disorder. The effect may be related to the proteases in kiwifruit. This in vitro study aimed to measure protein hydrolysis due to kiwifruit protease under gastric and duodenal conditions. A sequence of experiments incubated meat protein, with and without kiwifruit, with varying concentrations of pepsin and hydrochloric acid, at 37 °C for 60 min over the pH range 1.3–6.2 to simulate gastric digestion. Duodenal digestion was simulated by a further 120 min incubation at pH 6.4. Protein digestion efficiency was determined by comparing Kjeldahl nitrogen in pre- and post-digests. Where acid and pepsin concentrations were optimal for peptic digestion, hydrolysis was 80% effective and addition of kiwifruit made little difference. When pH was increased to 3.1 and pepsin activity reduced, hydrolysis decreased by 75%; addition of kiwifruit to this milieu more than doubled protein hydrolysis. This in vitro study has shown, when gastric pH is elevated, the addition of kiwifruit can double the rate of hydrolysis of meat protein. This novel finding supports the hypothesis that consumption of kiwifruit with a meal can increase the rate of protein hydrolysis, which may explain how kiwifruit relieves functional GI disorder.

Digestive function of the stomach

The core function of the human stomach is as an aid to digestion. The four key components of gastric digestive function are its function as a reservoir, acid secretion, enzyme secretion and its role in gastrointestinal motility. The reservoir capacity of the stomach allows it to increase its volume significantly while internal pressure increases only slightly. Acid secretion is a very important non-immunological defence against invading pathogens as well as being an important mechanism for vertebrates to have more complex diets. Stimulation of acid secretion involves the translocation of H+/K+-ATPases to the apical membrane of the parietal cell. The stomach is also an important endocrine organ producing an array of peptide hormones important for both enteric and non-enteric physiology including ghrelin and leptin. In addition to the reservoir function, the stomach also plays an important motility role as a pump, which anatomically is provided by the distal two thirds of the corpus, the antrum and the pylorus. This article examines those four functions and the role that they play in normal physiologic function and examines how they may play a role in pathologic states.

Development of a simple model for predicting need for surgery in patients who initially undergo conservative management for adhesive small bowel obstruction

BACKGROUND

Among patients with adhesive small bowel obstruction (ASBO) initially managed with a conservative strategy, predicting risk of operation is difficult.

METHODS

We investigated ASBO patients at 2 different periods to derive and validate a clinical prediction model for risk of operation.

RESULTS

One hundred fifty-four patients were enrolled into the derivation cohort and 96 into the validation cohort. Based on the derived scoring, including age > or =65 years, presence of ascites, and gastrointestinal drainage volume >500 mL on day 3, each patient was classified into 1 of 4 risk classes from low risk to high risk. When applied to the validation cohort, the positive predictive value (PPV) for operation in the high-risk class was 72%, while the negative predictive value (NPV) in the low-risk class was 100% with high sensitivity (100%) and specificity (96%).

CONCLUSIONS

The prediction model performs well for risk stratification of need for surgical intervention following conservative strategy among ASBO patients.

[Frequency and risk factors of biological adrenal insufficiency screened by the 250 microg Synacthene stimulation test after a prolonged course of systemic glucocorticoid therapy. A study of 100 patients]

PURPOSE

The frequency of adrenal insufficiency after a prolonged, continuous course of oral high-dose corticosteroids is poorly documented. We evaluated it retrospectively in our internal medicine department.

METHODS

The patients were included between February 2000 and June 2007 and were administered a Synacthene 250 microg test (ST250) before tapering prednisone dose below 5mg per day. A non-responsive test was defined by a cortisol increase below 18 microg/dL, 60 min after stimulation. We also studied the risk factors associated with biological adrenal insufficiency by a multivariate logistic regression analysis.

RESULTS

Hundred patients were included (mean age: 61.5+/-16.3 years). Mean initial dose of corticosteroids was 65.5+/-112 mg/d. Forty-five patients failed to respond to the ST250. A normal ST250 was negatively associated with a duration of corticosteroids therapy longer than 19.5 months (OR=0.38 [0.15-0.94]; p=0.04) and positively with an age over 63.5 years (OR=2.5 [1.1-6.4]; p=0.05). Two patients experienced a clinical adrenal insufficiency crisis.

CONCLUSION

Biological adrenal insufficiency is very common after a prolonged course of oral high-dose corticosteroids. The risk does not seem to increase with age. The clinical benefit of a systematic ST250 at the time of corticosteroids withdrawal followed by hydrocortisone substitution if the test is non responsive remains unknown, and this practice is still a matter of debate.

Colorectal cancer distribution in 220 Indian patients undergoing colonoscopy

AIM

Colorectal cancer is one of the major cancers in the developed world. The incidence of colorectal cancer is low in India. The aim of the present study was to describe the anatomical distribution and age at diagnosis of colorectal cancer in India.

METHODS

Retrospective descriptive analysis of anatomical distribution, age at diagnosis and demography of 220 cases (149 [67.7%] men) of adenocarcinoma of the colon or rectum diagnosed at colonoscopy over a period of five years.

RESULTS

The mean age at diagnosis was 58.4 years (SD 13.3; range 23-85 years). Twenty-eight (12.7%) cases were below the age of 40 years. The majority (31.8%) cases were aged between 61-70 years. Most of the tumors (n=163, 74%) were located distal to the splenic flexure. Multivariate logistic regression analysis showed that bleeding per rectum (OR 2.8; 95% CI 1.2-6.2) was associated with distal cancer, and palpable mass (OR 3.9; 95% CI 1.7-8.6) was associated with proximal cancer.

CONCLUSIONS

Almost one-third of the colorectal cancers in this series occurred in the seventh decade and were located distal to the splenic flexure.