Accessory Digestive Organs Research Articles

Hemoglobin and hematocrit levels are positively correlated with phase angle in mixed cancer patients: an exploratory cross-sectional study.

The aim of this study is to verify the correlationbetween hemoglobin (Hb) and hematocrit (Ht) levels with phase angle (PhA) values in patients with cancer of the gastrointestinal tract and accessory digestive organs. A cross-sectional study was conducted with 82 patients (38 females/44 males) diagnosed with cancer of gastrointestinal tract and accessory organs of digestion. Hb (g/dL) and Ht (%) levels were assessed by the cyanomethemoglobin and microhematocrit methods, respectively. Body composition and PhA were evaluated by the bioelectrical impedance analysis (BIA). The cut-off point used to classify patients with low PhA was set < 4°. Fifty-five (67%) of patients had PhA ≥ 4° values. We observed that body weight, BMI, fat mass, % weight loss, Ht, and Hb were higher in the PhA ≥ 4° group than in the PhA < 4° group. In the regression analysis, we found a positive association between PhA, Ht, and Hb without and after adjustment for sex, age, BMI, and type of treatment. In mixed cancer patients, there was a positive correlation between blood-red cell markers and PhA. This may be evidence that we can use of hematological parameters to suggest changes in PhA values during oncological treatment.

Characteristics of the Digestive Tract of Dogs and Cats.

As for other mammals, the digestive system of dogs (facultative carnivores) and cats (obligate carnivores) includes the mouth, teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, and accessory digestive organs (salivary glands, pancreas, liver, and gallbladder). These carnivores have a relatively shorter digestive tract but longer canine teeth, a tighter digitation of molars, and a greater stomach volume than omnivorousmammals such as humans and pigs. Both dogs and cats have no detectable or a very low activity of salivary α-amylase but dogs, unlike cats, possess a relativelyhighactivity of pancreatic α-amylase. Thus, cats select low-starch foods but dogs can consume high-starch diets. In contrast tomany mammals, the vitamin B12 (cobalamin)-binding intrinsic factor for the digestion and absorption of vitamin B12 is produced in: (a) dogs primarily by pancreatic ductal cells and to a lesser extent the gastric mucosa; and (b) cats exclusively by the pancreatic tissue. Amino acids (glutamate, glutamine, and aspartate) are the main metabolic fuels in enterocytes of the foregut. The primary function of the small intestine is to digest and absorb dietary nutrients, and its secondary function is to regulate the entry of dietary nutrients into the blood circulation, separate the external from the internal milieu, and perform immune surveillance. The major function of the large intestine is to ferment undigested food (particularly fiber and protein) and to absorb water, short-chain fatty acids (serving as major metabolic fuels for epithelial cells of the large intestine), as well as vitamins. The fermentation products, water, sloughed cells, digestive secretions, and microbes form feces and then pass into the rectum for excretion via the anal canal. The microflora influences colonic absorption and cell metabolism, as well as feces quality. The digestive tract is essential for the health, survival, growth, and development of dogs and cats.

Front cover

The cover image is based on the Original Article Histological and histochemical characteristics of the oral, pharyngeal and accessory digestive organs in the water monitor lizard (Varanus salvator) from Thailand by Nattawut Srichairat et al., https://doi.org/10.1111/ahe.12846.

Histological and histochemical characteristics of the oral, pharyngeal and accessory digestive organs in the water monitor lizard (Varanus salvator) from Thailand.

Srichairat, N., Taksintum, W., & Chumnanpuen, P. (2022). Histological and histochemical characteristics of the oral, pharyngeal and accessory digestive organs in the water monitor lizard (Varanus salvator) from Thailand. Anatomia Histologia Embryologia, 51, https://doi.org/10.1111/ahe.12846. The water monitor lizard (Varanussalvator) is largely distributed in Southeast Asia, especially Thailand, which the microanatomical structure studies on this particular species have been limited. Therefore, the purpose of this study is to examine and describe the oral, pharyngeal and accessory digestive organs' histological and histochemical characteristics. Histological and histochemical examinations were performed on the two specimens (male and female). The majority of V.salvator oral, pharyngeal and accessory digestive organs are similar to those of other vertebrates, according to the results of the histological investigation. However, several unique characteristics have been observed, such as the dentine lamella (plicidentine fold) at the tooth root structure was discovered to be attached to the jaw bone, the absence of lingual papillae and taste buds on the tongue, and the absence of inner surface folding structures in the gallbladder. Regarding mucin histochemical investigation, acid and neutral mucins were discovered in the pharyngeal glands of V.salvator, whereas only acid mucin was found in the mandibular salivary glands. This study reveals the histological and histochemical characteristics of V.salvator oral, pharyngeal and accessory digestive organs, which could be employed to improve digestive tract function, as well as the necessity of understanding animal digestive processes.

Natural Products of Marine Origin for the Treatment of Colorectal and Pancreatic Cancers: Mechanisms and Potential.

Gastrointestinal cancer refers to malignancy of the accessory organs of digestion, and it includes colorectal cancer (CRC) and pancreatic cancer (PC). Worldwide, CRC is the second most common cancer among women and the third most common among men. PC has a poor prognosis and high mortality, with 5-year relative survival of approximately 11.5%. Conventional chemotherapy treatments for these cancers are limited due to severe side effects and the development of drug resistance. Therefore, there is an urgent need to develop new and safe drugs for effective treatment of PC and CRC. Historically, natural sources—plants in particular—have played a dominant role in traditional medicine used to treat a wide spectrum of diseases. In recent decades, marine natural products (MNPs) have shown great potential as drugs, but drug leads for treating various types of cancer, including CRC and PC, are scarce. To date, marine-based drugs have been used against leukemia, metastatic breast cancer, soft tissue sarcoma, and ovarian cancer. In this review, we summarized existing studies describing MNPs that were found to have an effect on CRC and PC, and we discussed the potential mechanisms of action of MNPs as well as future prospects for their use in treating these cancers.

Can Periodontitis Affect the Health and Disease of the Digestive System? A Comprehensive Review of Epidemiological Evidence and Biological Mechanisms

Purpose of ReviewThere is increasing evidence on the connections between chronic oral inflammation/infection and the pathophysiological conditions of the gastrointestinal tract and accessory organs of digestion. The aim of this review is to provide a critical synthesis regarding the epidemiological, clinical, and in vivo associations between periodontitis and the most relevant diseases of the digestive system.Recent FindingsAn increasing body of dental and medical literature is supporting the gum-gut axis as a relevant mechanism to explain the associations between periodontitis and systemic diseases. Indeed, shared microbiological and immunological pathways have been identified between periodontitis and gut diseases, and translocation of oral bacteria to the lower parts of the digestive system has been postulated as a driver for peptic ulcers, inflammatory bowel disease, liver disease, and ultimately digestive cancers.SummaryFor the upper digestive tract, epidemiologic association between periodontitis and gastroesophageal reflux disease or squamous cell carcinoma remains conflicting, despite oral keystone pathogens having been consistently found in esophageal and gastric cancer tissue biopsies. The oral cavity represents a reservoir for Helicobacter pylori, with periodontal therapy increasing the eradication and the non-recurrence rate of the infection. Regarding bowel diseases, gut dysbiosis is being progressively ascertained in close relation to periodontal infection, and periodontitis is being investigated among the risk indicators for colorectal cancer. Lastly, non-alcoholic fatty liver disease and cirrhosis were epidemiologically linked to periodontitis, while its association with pancreatic tumors represents one of the most intriguing fields of research in periomedicine.

Radiotherapy-Induced Digestive Injury: Diagnosis, Treatment and Mechanisms.

Radiotherapy is one of the main therapeutic methods for treating cancer. The digestive system consists of the gastrointestinal tract and the accessory organs of digestion (the tongue, salivary glands, pancreas, liver and gallbladder). The digestive system is easily impaired during radiotherapy, especially in thoracic and abdominal radiotherapy. In this review, we introduce the physical classification, basic pathogenesis, clinical characteristics, predictive/diagnostic factors, and possible treatment targets of radiotherapy-induced digestive injury. Radiotherapy-induced digestive injury complies with the dose-volume effect and has a radiation-based organ correlation. Computed tomography (CT), MRI (magnetic resonance imaging), ultrasound (US) and endoscopy can help diagnose and evaluate the radiation-induced lesion level. The latest treatment approaches include improvement in radiotherapy (such as shielding, hydrogel spacers and dose distribution), stem cell transplantation and drug administration. Gut microbiota modulation may become a novel approach to relieving radiogenic gastrointestinal syndrome. Finally, we summarized the possible mechanisms involved in treatment, but they remain varied. Radionuclide-labeled targeting molecules (RLTMs) are promising for more precise radiotherapy. These advances contribute to our understanding of the assessment and treatment of radiation-induced digestive injury.

Proliferating cell nuclear antigen clamp associated factor, a potential proto-oncogene with increased expression in malignant gastrointestinal tumors.

Gastrointestinal (GI) cancers, including malignancies in the gastrointestinal tract and accessory organs of digestion, represent the leading cause of death worldwide due to the poor prognosis of most GI cancers. An investigation into the potential molecular targets of prediction, diagnosis, prognosis, and therapy in GI cancers is urgently required. Proliferating cell nuclear antigen (PCNA) clamp associated factor (PCLAF), which plays an essential role in cell proliferation, apoptosis, and cell cycle regulation by binding to PCNA, is a potential molecular target of GI cancers as it contributes to a series of malignant properties, including tumorigenesis, epithelial-mesenchymal transition, migration, and invasion. Furthermore, PCLAF is an underlying plasma prediction target in colorectal cancer and liver cancer. In addition to GI cancers, PCLAF is also involved in other types of cancers and autoimmune diseases. Several pivotal pathways, including the Rb/E2F pathway, NF-κB pathway, and p53-p21 cascade, are implicated in PCLAF-mediated diseases. PCLAF also contributes to some diseases through dysregulation of the p53 pathway, WNT signal pathway, MEK/ERK pathway, and PI3K/AKT/mTOR signal cascade. This review mainly describes in detail the role of PCLAF in physiological status and GI cancers. The signaling pathways involved in PCLAF are also summarized. Suppression of the interaction of PCLAF/PCNA or the expression of PCLAF might be potential biological therapeutic strategies for GI cancers.

Medicinal plants used against gastrointestinal complaints in district Budgam of Jammu and Kashmir - An ethnomedicinal study

Background: The current study was the first to target on gastrointestinal illnesses and associated traditional recipes in Jammu and Kashmir's Budgam area. Gastrointestinal disorders affect any part of the gastrointestinal system, from the esophagus to the rectum, as well as the accessory digestive organs. The knowledge about plants used for the treatment gastrointestinal disorders is rapidly depleting in the study area and hence it becomes important to document this valuable knowledge. Methods: Extensive surveys were conducted in the study area during March 2019 to July 2020 for the collection of medicinally important plants and the traditional knowledge associated with them. In a total 35 informants (22 males, 13 females) were interviewed aged between 29-80 years to collect the data using group discussions and semi-structured interviews. The interviews were carried out in local dialect and all the documented data was then translated into English. Various ethnobotanical indices, including informant consensus factor and use value, were employed to evaluate the gathered information. Results: A total of 56 plant species belonging to 24 families and 47 genera were reported to be used against gastrointestinal disorders in Budgam region of Jammu and Kashmir. Among 24 families, Asteraceae was the dominant family (12 species) of the total reported taxa in the study area and leaves were the most utilized plant part with decoction as the major mode of herbal recipe preparation. Highest ICF (Informant consensus factor) of 1 was reported for vomiting and Artemisia absinthium recorded the highest UV (Use value) of 0.74. Conclusion: Local inhabitants still prioritize herbal medicines as an effective way to treat a wide variety of ailments. Elders of the study area are well equipped with indigenous knowledge about medicinal plants, but young people are not much interested in herbal practices. Thus, valuable knowledge about the use of plants is on the verge of decline. Hence there is a dire need to document these valuable medicinal plants and the traditional treasure associated with them. In addition, plants reported with high UV should be subjected for further phytochemical and pharmacological investigation to authenticate indigenous uses. Keywords: Medicinal plants, Ethnomedicine, Traditional knowledge, Gastrointestinal complaints, Budgam, J&amp;K.

Role of Leptin in the Digestive System.

Leptin is a pluripotent peptide hormone produced mainly by adipocytes, as well as by other tissues such as the stomach. Leptin primarily acts on the central nervous system, particularly the hypothalamus, where this hormone regulates energy homeostasis and neuroendocrine function. Owing to this, disruption of leptin signaling has been linked with numerous pathological conditions. Recent studies have also highlighted the diverse roles of leptin in the digestive system including immune regulation, cell proliferation, tissue healing, and glucose metabolism. Of note, leptin acts differently under physiological and pathological conditions. Here, we review the current knowledge on the functions of leptin and its downstream signaling in the gastrointestinal tract and accessory digestive organs, with an emphasis on its physiological and pathological implications. We also discuss the current therapeutic uses of recombinant leptin, as well as its limitations.

Updated Review on the Role of Curcumin in Gastrointestinal Cancers.

Malignant conditions of the gastrointestinal tract and accessory organs of digestion, including the oral cavity, esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus, are referred to as gastrointestinal cancers. Curcumin is a natural compound derived from turmeric with a wide range of biological activities. Several in vitro and in vivo studies have investigated the effects of curcumin on gastrointestinal cancers. In the current review, we aimed to provide an updated summary on the recent findings regarding the beneficial effects of curcumin on different gastrointestinal cancers in the recent decade. For this purpose, ScienceDirect," "Google Scholar," "PubMed," "ISI Web of Knowledge," and "Wiley Online Library" databases were searched using "curcumin", "cancer", and "gastrointestinal organs" as keywords. In vitro studies performed on different gastrointestinal cancerous cell lines have shown that curcumin can inhibit cellgrowth through cycle arrest at the G2/M and G1 phases, as well as stimulated apoptosis and autophagy by interacting with multiple molecular targets. In vivo studies performed in various animal models have confirmed mainly the chemopreventive effects of curcumin. Several nano-formulations have been proposed to improve the bioavailability of curcuminand increase its absorption. Moreover, curcumin has been used in combinations with many anti-tumor drugs to increase theiranticarcinogenic properties. Taken together, curcumin falls within the category of plant-derived substances capable of preventing or treating gastrointestinal cancers. Further studies, particularly clinical trials, on the efficacy and safety of curcumin are suggested in this regard.

Targeting the tumour immune microenvironment for cancer therapy in human gastrointestinal malignancies.

Gastrointestinal (GI) cancer is a malignancy of the GI tract and accessory digestive organs. GI cancer patients develop resistance to chemotherapy, targeted therapy drugs and immune therapies. Although immune checkpoint inhibitors have shown promising clinical results in melanoma, etc., immune checkpoint blockade responds in only a subset of colorectal cancer (CRC) patients with microsatellite instability-high (MSI-H) tumours. The tumour immune microenvironment (TIME) has a dynamic nature during malignant progression to which all the cells in the TIME contribute. Recent studies have highlighted the role of the TIME in the therapy resistance of cancer. Immune suppressive cells, such as tumour-associated macrophages, regulatory T cells, and myeloid-derived suppressor cells, consist of a suppressive TIME to resist immune reactions. Combination approaches used to target the TIME, such as radiotherapy, chemotherapy, targeted therapy combined with checkpoint blockers or immune cell therapy, in addition to mono-immunotherapy, may provide better therapy responses. This review provides an analysis of recent developments regarding the role of the TIME in malignant progression, immunotherapy and the development of drug resistance in GI tract cancer, especially CRC, as well as approaches to overcome microenvironment-mediated resistance.

Kallikrein-related peptidases and associated microRNAs as promising prognostic biomarkers in gastrointestinal malignancies.

Gastrointestinal (GI) malignancies represent a wide spectrum of diseases of the GI tract and its accessory digestive organs, including esophageal (EC), gastric (GC), hepatocellular, pancreatic (PC) and colorectal cancers (CRC). Malignancies of the GI system are responsible for nearly 30% of cancer-related morbidity and approximately 40% of cancer-related mortality, worldwide. For this reason, the discovery of novel prognostic biomarkers that can efficiently provide a better prognosis, risk assessment and prediction of treatment response is an imperative need. Human kallikrein-related peptidases (KLKs) are a subgroup of trypsin and chymotrypsin-like serine peptidases that have emerged as promising prognosticators for many human types of cancer, being aberrantly expressed in cancerous tissues. The aberrant expression of KLKs in human malignancies is often regulated by KLK/microRNAs (miRNAs) interactions, as many miRNAs have been found to target KLKs and therefore alter their expression levels. The biomarker utility of KLKs has been elucidated not only in endocrine-related human malignancies, including those of the prostate and breast, but also in GI malignancies. The main purpose of this review is to summarize the existing information regarding the prognostic significance of KLKs in major types of GI malignancies and highlight the regulatory role of miRNAs on the expression levels of KLKs in these types of cancer.

Localization and role of metabotropic glutamate receptors subtype 5 in the gastrointestinal tract.

Metabotropic glutamate receptor subtype 5 (mGluR5) is a Group I mGlu subfamily of receptors coupled to the inositol trisphosphate/diacylglycerol pathway. Like other mGluR subtypes, mGluR5s contain a phylogenetically conserved, extracellular orthosteric binding site and a more variable allosteric binding site, located on the heptahelical transmembrane domain. The mGluR5 receptor has proved to be a key pharmacological target in conditions affecting the central nervous system (CNS) but its presence outside the CNS underscores its potential role in pathologies affecting peripheral organs such as the gastrointestinal (GI) tract and accessory digestive organs such as the tongue, liver and pancreas. Following identification of mGluR5s in the mouth, various studies have subsequently demonstrated its involvement in mechanical allodynia, inflammation, pain and oral cancer. mGluR5 expression has also been identified in gastroesophageal vagal pathways. Indeed, experimental and human studies have demonstrated that mGluR5 blockade reduces transient lower sphincter relaxation and reflux episodes. In the intestine, mGluR5s have been shown to be involved in the control of intestinal inflammation, visceral pain and the epithelial barrier function. In the liver, mGluR5s have a permissive role in the onset of ischemic injury in rat and mice hepatocytes. Conversely, livers from mice treated with selective negative allosteric modulators and mGluR5 knockout mice are protected against ischemic injury. Similar results have been observed in experimental models of free-radical injury and in vivo mouse models of acetaminophen intoxication. Finally, mGluR5s in the pancreas are associated with insulin secretion control. The picture is, however, far from complete as the review attempts to establish in particular as regards identifying specific targets and innovative therapeutic approaches for the treatment of GI disorders.

Ontogeny of the Digestive System of Atlantic Salmon (Salmo salar L.) and Effects of Soybean Meal from Start-Feeding

Despite a long history of rearing Atlantic salmon in hatcheries in Norway, knowledge of molecular and physiological aspects of juvenile development is still limited. To facilitate introduction of alternative feed ingredients and feed additives during early phases, increased knowledge regarding the ontogeny of the digestive apparatus in salmon is needed. In this study, we characterized the development of the gastrointestinal tract and accessory digestive organs for five months following hatch by using histological, biochemical and molecular methods. Furthermore, the effects of a diet containing 16.7% soybean meal (SBM) introduced at start-feeding were investigated, as compared to a fishmeal based control diet. Salmon yolk sac alevins and fry were sampled at 18 time points from hatch until 144 days post hatch (dph). Histomorphological development was investigated at 7, 27, 46, 54 and 144 dph. Ontogenetic expression patterns of genes encoding key digestive enzymes, nutrient transporters, gastrointestinal peptide hormones and T-cell markers were analyzed from 13 time points by qPCR. At 7 dph, the digestive system of Atlantic salmon alevins was morphologically distinct with an early stomach, liver, pancreas, anterior and posterior intestine. About one week before the yolk sac was internalized and exogenous feeding was started, gastric glands and developing pyloric caeca were observed, which coincided with an increase in gene expression of gastric and pancreatic enzymes and nutrient transporters. Thus, the observed organs seemed ready to digest external feed well before the yolk sac was absorbed into the abdominal cavity. In contrast to post-smolt Atlantic salmon, inclusion of SBM did not induce intestinal inflammation in the juveniles. This indicates that SBM can be used in compound feeds for salmon fry from start-feeding to at least 144 dph and/or 4-5 g body weight.

Human gut microbiota: does diet matter?

The human oro-gastrointestinal (GI) tract is a complex system, consisting of oral cavity, pharynx, oesophagus, stomach, small intestine, large intestine, rectum and anus, which all together with the accessory digestive organs constitute the digestive system. The function of the digestive system is to break down dietary constituents into small molecules and then absorb these for subsequent distribution throughout the body. Besides digestion and carbohydrate metabolism, the indigenous microbiota has an important influence on host physiological, nutritional and immunological processes, and commensal bacteria are able to modulate the expression of host genes that regulate diverse and fundamental physiological functions. The main external factors that can affect the composition of the microbial community in generally healthy adults include major dietary changes and antibiotic therapy. Changes in some selected bacterial groups have been observed due to controlled changes to the normal diet e.g. high-protein diet, high-fat diet, prebiotics, probiotics and polyphenols. More specifically, changes in the type and quantity of non-digestible carbohydrates in the human diet influence both the metabolic products formed in the lower regions of the GI tract and the bacterial populations detected in faeces. The interactions between dietary factors, gut microbiota and host metabolism are increasingly demonstrated to be important for maintaining homeostasis and health. Therefore the aim of this review is to summarise the effect of diet, and especially dietary interventions, on the human gut microbiota. Furthermore, the most important confounding factors (methodologies used and intrinsic human factors) in relation to gut microbiota analyses are elucidated.

Together We Do Great Things

Eighty years ago, 10 men met in the New York City home of Samuel Weiss to found the organization that would become the American College of Gastroenterology. Their goals were sixfold: to unite in one organization qualified physicians, teachers, and research workers of high standing in gastroenterology; to emphasize and to advance the clinical practice of diseases and disorders of the gastrointestinal tract and accessory organs of digestion, including nutrition; to further the study of gastroenterology and allied subjects; to encourage gastrointestinal research and publish the results; to promote greater interest among practicing physicians in diseases of the gastrointestinal tract and further their training in clinical gastroenterology; and to maintain and promote the highest standards in medical practice, medical education, and research in the field. These goals still animate the College today.

Weight Assessment of Some Accessory Digestive Organs in the Adult African Giant Pouched Rat (&lt;i&gt;Cricetomys gambianus&lt;/i&gt;, Waterhouse-1840)

The African giant pouched rat is a wild rodent of the Muridae family that is predominant in Africa, south of Sahara (Rosevear, 1969). They are adaptable to several environmental conditions including lowlands and highlands (Bigalke, 1964). The rats are widely distributed in all parts of Nigeria, where they are consumed as 'bushmeat'. The smoked carcasses of the rodent are often seen in village markets. Attempts have been made to breed and rear the rats in captivity, for food (Ajayi, 1975). For effective breeding and domestication, there is a need to quantify the digestive organs of the adult African giant pouched rat. This will give an insight into the efficiency of their digestive system, the knowledge of which may be employed in the breeding programmes, or as animal models for feed formulation and nutrient trials. This study was initiated based on the paucity of literature on the gross morphometry of accessory digestive organs in the adult African giant pouched rat. The study was aimed at determining the weights of the liver, gall bladder and pancreas in adult African giant pouched rats in both absolute and relative terms, and to compare the results with what has been reported in other rodents.

Funktionsuntersuchungen des oberen Gastrointestinaltraktes

Radionuclide procedures remain the most sensitive approaches for the measurement of in vivo physiology, biochemistry and metabolism, even in the light competing methods like endoscopy, manometry, MRI or ultrasound. The gastro-intestinal (GI) tract function is to digest food using various digestive juices and enzymes to facilitate absorption nutrients. Various segments of the GI tract (e.g. esophagus, stomach) coordinate in a complex yet precise way to control these processes. Accessory organs of digestion are i.e. the salivary glands. Functional alterations of these involved organs have been associated with various disease conditions. Nuclear medicine techniques provide physiological information about the integrity of the salivary glands and the drainage of the saliva. Esophageal scintigraphy is a non-invasive, quantitative method to objectively assess disturbances of esophageal bolus transit. Radionuclide studies of gastric emptying and motility are the most appropriate and physiologic tools available for studying gastric motor function. A Meckel scan is able to detect sites of ectopic gastric mucosa in the abdomen. This review summarizes the state-of-the-art of established but under-used scintigraphic techniques with an emphasis on their clinical applications and significance.

Age, sex, and weight at weaning influence organ weight and gastrointestinal development of weanling pigs

The present study was designed to determine the interrelationships between sex, weaning age, and weaning weight on aspects of physiological and gastrointestinal development in pigs. Forty-eight Large White × Landrace pigs were used in a factorial arrangement with the respective factors being: age at weaning (14 or 28 days), weight at weaning (heavy or light), sex (boar or gilt), and time after weaning (1, 7, and 14 days). At weaning, 48 pigs were removed from the sow: 16 pigs were then fasted for 24 h before euthanasia for determination of organ weights, gut histology, and enzymology, and 32 pigs were offered a high quality pelleted weaner diet ad libitum for subsequent assessment of organ weights, histology, and enzymology at 7 and 14 d after weaning. On Day 6 and 13 after weaning, 2 pigs from each group had their feed removed, and 24 h later were euthanased and similar measurements were taken. In general, the data highlighted the overall gastrointestinal underdevelopment of pigs weaned at 2 weeks of age and of pigs weaned light-for-age at either 2 or 4 weeks. Heavier body organs, gastrointestinal organs, and accessory digestive organs observed after weaning, except for the spleen, presumably reflected the increase in substrates available for cellular growth as feed intake increased after weaning, and the development of organs required to process this feed. Interestingly, the relative weights (% of liveweight) of the stomach and small intestine and, to a lesser extent, the caecum and colon, were greater in the light, 14-day-old weaned pigs, but these differences diminished with increasing time after weaning. Consistent effects due to age, weight, and sex were not observed for villous height and crypt depth, or for the specific activities of the brush-border and pancreatic enzymes measured. However, increases (P &lt; 0.001) in the activities of maltase (P�&lt;�0.001), glucoamylase (P &lt; 0.001), and sucrase (P = 0.020) (all expressed per gram of mucosa), and that of trypsin (per gram of pancreas), occurred by 14 days after weaning. This most likely reflected the inducible nature of these enzymes in response to the increasing intake of substrates provided in the diet. In contrast, the specific activity of lactase declined (P = 0.012) in the first 14 days after weaning. These data suggest that pigs weaned at 2 weeks of age and pigs weaned light-for-age at either 2 or 4 weeks have a less developed gastrointestinal tract, and that its development after weaning might proceed differently to that of pigs weaned older and heavier.