Childhood Crohn's disease and the efficacy of enteral diets

Meta-analysis: efficacy of exclusive enteral nutrition as induction therapy on disease activity index, inflammation and growth factors in paediatric Crohn's disease

BACKGROUND

There is evidence of inconsistency in sequelae of exclusive enteral nutrition (EEN) as induction therapy in paediatric patients with Crohn's disease (CD).

AIM

To investigate the potential effects of EEN on paediatric Crohn's disease activity index (PCDAI), inflammation and biochemical parameters in paediatric patients with CD.

METHODS

We performed a comprehensive systematic search of PubMed/MEDLINE, Web of Science, SCOPUS and Embase until 8 January 2022 regardless of the time of publication or language. Random-effects model was applied to combine the datasets. The main outcomes were analysed through mean difference (MD) and its 95% confidence interval (CI).

RESULTS

Forty six studies met eligibility criteria and were included in the meta-analysis. Pooled findings indicated that PCDAI score (MD of -27.24; 95% CI -31.84 to -22.64), calprotectin (MD of -842.83 mg/kg; CI -1018.24 to -667.42), CRP (pooled MD of -2.36 mg/dl; CI -2.68 to -2.03), and ESR (MD of -21.09 mm/h; CI -23.79 to -18.38), albumin (MD of 0.65 g/dl; CI 0.58 to 0.72), haemoglobin (MD of 1.12 g/dl; CI 0.87 to 1.37), weight (MD of 4.30 kg; CI 3.39 to 5.22), and height (MD of 0.98 cm; CI 0.35 to 1.62) improved significantly with EEN.

CONCLUSIONS

Adherence to EEN can have significant, beneficial effects as induction therapy in paediatric patients with CD.

Nutritional Therapy Strategies in Pediatric Crohn's Disease

The increase in incidences of pediatric Crohn's Disease (CD) worldwide has been strongly linked with dietary shifts towards a Westernized diet, ultimately leading to altered gut microbiota and disturbance in intestinal immunity and the metabolome. Multiple clinical studies in children with CD have demonstrated the high efficacy of nutritional therapy with exclusive enteral nutrition (EEN) to induce remission with an excellent safety profile. However, EEN is poorly tolerated, limiting its compliance and clinical application. This has spiked an interest in the development of alternative and better-tolerated nutritional therapy strategies. Several nutritional therapies have now been designed not only to treat the nutritional deficiencies seen in children with active CD but also to correct dysbiosis and reduce intestinal inflammation. In this review, we report the most recent insights regarding nutritional strategies in children with active CD: EEN, partial enteral nutrition (PEN), Crohn's disease exclusive diet (CDED), and CD treatment-with-eating diet (CD-TREAT). We describe their setup, efficacy, safety, and (dis)advantages as well as some of their potential mechanisms of action and perspectives. A better understanding of different nutritional therapeutic options and their mechanisms will yield better and safer management strategies for children with CD and may address the barriers and limitations of current strategies in children.

Enteral Nutrition in Adult Crohn's Disease: Toward a Paradigm Shift

Medical and surgical treatments for Crohn's disease are associated with toxic effects. Medical therapy aims for mucosal healing and is achievable with biologics, immunosuppressive therapy, and specialised enteral nutrition, but not with corticosteroids. Sustained remission remains a therapeutic challenge. Enteral nutrition, containing macro- and micro-nutrients, is nutritionally complete, and is provided in powder or liquid form. Enteral nutrition is a low-risk and minimally invasive therapy. It is well-established and recommended as first line induction therapy in paediatric Crohn's disease with remission rates of up to 80%. Other than in Japan, enteral nutrition is not routinely used in the adult population among Western countries, mainly due to unpalatable formulations which lead to poor compliance. This study aims to offer a comprehensive review of available enteral nutrition formulations and the literature supporting the use and mechanisms of action of enteral nutrition in adult Crohn's disease patients, in order to support clinicians in real world decision-making when offering/accepting treatment. The mechanisms of actions of enteral feed, including their impact on the gut microbiome, were explored. Barriers to the use of enteral nutrition, such as compliance and the route of administration, were considered. All available enteral preparations have been comprehensively described as a practical guide for clinical use. Likewise, guidelines are reported and discussed.

Growth failure in Crohn's disease children: may the first treatment have a role?

Introduction: Growth failure in children is a frequent feature of childhood-onset Crohn's disease (CD), and stunting can persist into adulthood. Growth is an important outcome by which to judge the effectiveness of therapies in children; currently available studies in CD children have focused on the short-term impact of treatments on growth, and there are limited data regarding the long-term effects of treatments upon growth. Areas covered: We designed the present article to review whether the first treatment performed in newly diagnosed CD children may have a role on the future growth course. We conducted a systematic literature search to identify relevant studies published on the PubMed database from January 2002 up to now. We found only six surveys that documented mid-term growth course in newly diagnosed CD patients. Expert commentary: In the last years there have been relevant advances in the clinical management of CD children; however, there is a lack of knowledge about the best strategy to reverse growth failure. Children treated with enteral nutrition have appropriate height and weight gain but do not reverse the growth course. Further surveys are required to better explore not only clinical outcomes but also long-term growth course following each therapeutic strategy.

Enteral Nutrition as Primary Therapy in Childhood Crohn's Disease: Control of Intestinal Inflammation and Anabolic Response

Crohn's disease in childhood is a chronic relapsing and remitting condition that can significantly impact normal growth and development. This influences choice of both initial and ongoing management. The goal of therapy is to induce and maintain remission with minimal side effects. Enteral nutrition is effective in active disease and will induce disease remission in most cases avoiding corticosteroid use. The high frequency of relapse means additional immunosuppressive therapies are usually required but nutrition remains a key priority as part of the subsequent management strategy.

Environmental factors in the relapse and recurrence of inflammatory bowel disease: a review of the literature

INTRODUCTION

The causes of relapse in patients with Crohn's disease (CD) and ulcerative colitis (UC) are largely unknown. This paper reviews the epidemiological and clinical data on how medications (non-steroidal anti-inflammatory drugs, estrogens and antibiotics), lifestyle factors (smoking, psychological stress, diet and air pollution) may precipitate clinical relapses and recurrence. Potential biological mechanisms include: increasing thrombotic tendency, imbalances in prostaglandin synthesis, alterations in the composition of gut microbiota, and mucosal damage causing increased permeability.

RESULTS

The clinical epidemiological data consistently reports positive associations between smoking and relapses in CD, and inverse ones with UC. For NSAIDs and estrogens, the epidemiological findings are inconsistent, although general antibiotic use was associated with a reduced risk of relapse in CD. High levels of stress were positively associated with relapse, although psychological interventions did not have therapeutic benefits. The limited work on diet has reported sulphur-containing foods are positively associated with relapse in UC, but there is no work in CD. Ecological data reported positive correlations between air pollution levels and IBD hospitalisations.

CONCLUSIONS

In the future, to clarify this area, more clinical epidemiological work is required where detailed drug types and doses, and complete dietary intakes are measured, in specific forms of IBD. Such work could provide guidance to both patients and doctors to help maintain remission.

Decline in presumptively protective gut bacterial species and metabolites are paradoxically associated with disease improvement in pediatric Crohn's disease during enteral nutrition

BACKGROUND

The gut microbiota is implicated in the pathogenesis of Crohn's disease (CD). Exclusive enteral nutrition (EEN) is a successful treatment, but its mode of action remains unknown. This study assessed serial changes in the fecal microbiota milieu during EEN.

METHODS

Five fecal samples were collected from CD children: 4 during EEN (start, 15, 30, end EEN approximately 60 days) and the fifth on habitual diet. Two samples were collected from healthy control subjects. Fecal pH, bacterial metabolites, global microbial diversity abundance, composition stability, and quantitative changes of total and 7 major bacterial groups previously implicated in CD were measured.

RESULTS

Overall, 68 samples were from 15 CD children and 40 from 21 control subjects. Fecal pH and total sulfide increased and butyric acid decreased during EEN (all P < 0.05). Global bacterial diversity abundance decreased (P < 0.05); a higher degree of microbiota composition stability was seen in control subjects than in CD children during EEN (at P ≤ 0.008). Faecalibacterium prausnitzii spp concentration significantly decreased after 30 days on EEN (P < 0.05). In patients who responded to EEN, the magnitude of the observed changes was greater and the concentration of Bacteroides/Prevotella group decreased (P < 0.05). All these changes reverted to pretreatment levels on free diet, and EEN microbiota diversity increased when the children returned to their free diet.

CONCLUSIONS

EEN impacts on gut microbiota composition and changes fecal metabolic activity. It is difficult to infer a causative association between such changes and disease improvement, but the results do challenge the current perception of a protective role for F. prausnitzii in CD.

Longer-term outcomes of nutritional management of Crohn's disease in children

BACKGROUND

While the short-term benefits of exclusive enteral nutrition (EEN) for induction of remission in children with Crohn's disease (CD) are well documented, the longer-term outcomes are less clear.

AIM

This retrospective study aimed to ascertain the outcomes for up to 24 months following EEN in a group of children with CD.

METHODS

Children treated with EEN as initial therapy for newly diagnosed CD over a 5-year period were identified. Details of disease activity, growth, and drug requirements over the period of follow-up were noted. Outcomes in children managed with EEN were compared to a group of children initially treated with corticosteroids.

RESULTS

Over this time period, 31 children were treated with EEN and 26 with corticosteroids. Twenty-six (84 %) of the 31 children treated with EEN entered remission. Children treated with EEN exhibited lower pediatric Crohn's disease activity index (PCDAI) scores at 6 months (p = 0.02) and received lower cumulative doses of steroids over the study period (p < 0.0001) than the group treated with corticosteroids. Height increments over 24 months were greater in the EEN group (p = 0.01). Although the median times to relapse were the same, the EEN group had a lower incidence of relapse in each time interval and survival curve analysis showed lower risk of relapse (p = 0.008).

CONCLUSIONS

EEN lead to multiple benefits beyond the initial period of inducing remission for these children, with positive outcomes over 2 years from diagnosis. Of particular clinical relevance to growing children was the reduced exposure to corticosteroids.

Alternative medicines as emerging therapies for inflammatory bowel diseases

Inflammatory bowel disease (IBD) can be divided into two major categories, ulcerative colitis (UC) and Crohn disease (CD). While the main cause(s) of IBD remain unknown, a number of interventional and preventive strategies have been proposed for use against CD and UC. Many reports have focused on the use of alternative natural medicines as potential therapeutic interventions in IBD patients with minimal side effects. While the use of alternative medicines may be effective in IBD patients that are refractory to corticosteroids or thiopurins, alternative treatment strategies are limited and require extensive clinical testing before being optimized for use in patients.

The efficacy of exclusive nutritional therapy in paediatric Crohn's disease, comparing fractionated oral vs. continuous enteral feeding

BACKGROUND

Nutritional therapy has an established role as induction therapy in paediatric Crohn's disease. However, compliance is the main difficulty and may be greatly influenced by the administration route.

AIM

To analyse the efficiency of exclusive nutrition to induce remission in children with Crohn's disease comparing fractionated oral vs. continuous enteral feeding.

METHODS

The medical records of 106 patients treated by exclusive nutritional therapy [Modulen IBD (R)] by either oral or continuous enteral route were reviewed retrospectively. Comparative analyses of remission rates, changes in anthropometry, Paediatric Crohn's disease Activity Index (PCDAI), laboratory indices and compliance rates were performed.

RESULTS

On exclusive enteral nutrition, at 8 weeks, 34/45 patients achieved remission in the oral group (75% on intention-to-treat analysis) and 52/61 (85%) in the enteral nutrition group (P = 0.157). All patients showed a significant decrease in disease severity assessed by PCDAI (P < 0.0001) and significant improvements in anthropometric measures and inflammatory indices. No difference was observed whether Modulen IBD was administered orally or by continuous enteral feeding, apart from weight gain, which was greater in the enteral group (P = 0.041). In a subgroup of patients, mucosal healing was evidenced on follow-up endoscopies showing a clear correlation to remission. Compliance rates (87% and 90%) were similar. Nevertheless, noncompliant patients had lower mucosal healing and remission rates.

CONCLUSIONS

These retrospective data suggest that the use of fractionated oral nutritional therapy might be as efficacious as continuous enteral administration to induce remission and mucosal healing in children with Crohn's disease. However, appropriate prospective clinical trials are needed to confirm these findings.

The universe of immune deficiencies in Crohn's disease: a new viewpoint for an old disease?

Crohn's disease (CD) is generally considered a multifactorial disorder, since different genetic and environmental factors are thought to play a role in its pathogenesis. Recently, genome wide linkage studies allowed to identify the association of several loci with the increased risk of CD, although it is still unclear how they interact with environmental factors in causing the disease. The fact that many CD-risk-related genes are involved in the function of phagocytes seems in agreement with the well known role of these cells in CD histopathology. Functional defects in cytokine production or in clearance of bacteria in CD patients have recently been reported. Growing evidence that CD could arise from primary phagocyte immunodeficiency is also coming from the study of cases with early onset in infancy. We review such evidences starting from selected cases and discuss the clinical implications of these findings.

Curcumin suppresses p38 mitogen-activated protein kinase activation, reduces IL-1beta and matrix metalloproteinase-3 and enhances IL-10 in the mucosa of children and adults with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a major source of morbidity in children and adults. Its incidence is rising, particularly in young people. IBD carries a lifelong risk of cancer, which is proportional to disease duration. Drug and surgical treatments rarely offer cure and often carry a high side effect burden. Dietary therapy is highly effective in Crohn's disease. For these reasons, there is much interest in developing novel dietary treatments in IBD. Curcumin, a component of the spice turmeric, and an anti-inflammatory and anti-cancer agent, shows preclinical and clinical potential in IBD. Its mechanisms of action are unknown. Our aim was to assess the effect of curcumin on key disease mediators p38 mitogen-activated protein kinase (MAPK), IL-1beta, IL-10 and matrix metalloproteinase-3 (MMP-3) in the gut of children and adults with IBD. Colonic mucosal biopsies and colonic myofibroblasts (CMF) from children and adults with active IBD were cultured ex vivo with curcumin. p38 MAPK, NF-kappaB and MMP-3 were measured by immunoblotting. IL-1beta and IL-10 were measured by ELISA. We show reduced p38 MAPK activation in curcumin-treated mucosal biopsies, enhanced IL-10 and reduced IL-1beta. We demonstrate dose-dependent suppression of MMP-3 in CMF with curcumin. We conclude that curcumin, a naturally occurring food substance with no known human toxicity, holds promise as a novel therapy in IBD.

Polymeric formula has direct anti-inflammatory effects on enterocytes in an in vitro model of intestinal inflammation

Exclusive enteral nutrition using polymeric formula (PF) is a well-established therapeutic option for active Crohn's disease; however, its mechanisms of action are unknown. We investigated the anti-inflammatory effects of PF in an in vitro model of epithelial cell inflammation. PF did not affect cell viability over a range of dilutions, but when PF was added to the culture medium the interleukin (IL)-8 response to proinflammatory stimuli was significantly reduced. This effect was due to PF acting directly on the cells as the IL-8 response was still reduced when PF was separated from the proinflammatory stimuli in a 2-compartment system. In the presence of PF, nuclear factor (NF)-kappaB nuclear migration was not inhibited; however, IkappaBalpha degradation was delayed. PF has direct anti-inflammatory effects upon immortalized colonic enterocytes. Therefore PF may, in part, modulate gut inflammation by directly reducing the inflammatory response of the intestinal epithelium.

Nocturnal nasogastric refeeding for hospitalized adolescent boys with anorexia nervosa

Boys with anorexia nervosa have nutritional needs exceeding those of their female counterparts. For many males with anorexia nervosa, oral refeeding alone may result in low discharge weight, a critical risk factor in relapse. This study compared the short-term outcomes of oral refeeding (OR) and a combination of OR with supplemental nocturnal nasogastric refeeding (NNGR) in a sample of hospitalized boys. This was a retrospective chart review with a cohort design. Subjects were partitioned into: The OR group (n = 8, mean age = 14.9, SD = 1.7) and the OR + NNGR group (n = 6, mean age = 13.8, SD = 2.0). The NNGR group had greater increase in weight and Body Mass Index. Their average length of hospitalization was also shorter. Nocturnal nasogastric refeeding, complementing oral refeeding, should be considered as an alternative initial therapy for weight restoration in males with anorexia nervosa.

Anti-inflammatory and growth-stimulating effects precede nutritional restitution during enteral feeding in Crohn disease

OBJECTIVES

Exclusive enteral feeding reduces inflammation and improves well being, nutrition and growth in children with active Crohn disease. Whether improved growth and increases in growth-related proteins are a consequence of improved nutrition or a reduced inflammation is not known. This study was undertaken to test the hypothesis that changes in growth-related proteins are related to decreased inflammation, rather than improvement in nutritional status.

METHODS

Twelve children with active Crohn disease treated for 6-weeks with exclusive enteral feeding were studied at days 0, 3, 7, 14, 21, 28, and 56. The Paediatric Crohn's Disease Activity Index (PCDAI), weight, triceps skinfold thickness, and midupper arm circumference were recorded. C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin-6 (IL-6), insulin-like growth factor (IGF-I), IGF-binding protein (IGFBP-3), and leptin were measured at each visit. Wilcoxon matched-pairs signed-rank test was used to compare day 0 with follow-up data.

RESULTS

Significant improvements (P < 0.05) occurred by day 3 in inflammatory parameters (ESR, IL-6) and by day 7 in PCDAI, CRP, and IGF-I. These changes preceded any significant changes in nutritional parameters (weight-for-age Z score and midupper arm circumference day 14, triceps skinfold thickness day 21).

CONCLUSIONS

Early increases in IGF-I during treatment of Crohn disease are attributable to the anti-inflammatory effect of the enteral feed rather than nutritional restitution.

Essential fatty acid status in paediatric Crohn's disease: relationship with disease activity and nutritional status

BACKGROUND

Active paediatric Crohn's disease is associated with nutritional deficiencies and altered nutrient intake. The availability of essential fatty acids (linoleic and alpha-linolenic acids) or their derivatives (arachidonic and eicosapentaenoic acids) may alter in plasma and cell membrane phospholipid in protein-energy malnutrition in children and in Crohn's disease in adults.

AIM

To investigate the relationship of fatty acid phospholipid profiles with disease activity and nutritional status in paediatric Crohn's disease.

METHODS

The fatty acid (proportionate) composition of plasma and erythrocyte phosphatidylcholine was determined in 30 patients (10.3-17.0 years) stratified into active and quiescent Crohn's disease (paediatric Crohn's disease activity index) and high and low body mass (body mass index centile).

RESULTS

In plasma phosphatidylcholine, active disease activity was associated with a lower level of alpha-linolenic acid compared with that in quiescent disease (P < 0.05). A body mass index below the 50th centile was associated with active Crohn's disease, low linoleic and alpha-linolenic acids and high arachidonic acid (P < 0.05) in plasma phosphatidylcholine, and low alpha-linolenic acid in erythrocyte phosphatidylcholine. These findings could not be explained through differences in habitual dietary fat intake.

CONCLUSION

In paediatric Crohn's disease, a low body mass index centile and high disease activity are associated with altered profiles of essential fatty acids and their derivatives, which may reflect altered metabolic demand.

Review article: nutrition and adult inflammatory bowel disease

Major advances in the understanding of the aetio-pathogenesis and genetics of inflammatory bowel disease have been accompanied by an escalation in the sophistication of immunomodulatory inflammatory bowel disease therapeutics. However, the basic 'triple' therapy (5-aminosalicylates, corticosteroids, azathioprine) and nutrition have maintained their central role in the management of patients with inflammatory bowel disease over recent decades. This review provides an overview of the supportive and therapeutic perspectives of nutrition in adult inflammatory bowel disease. The objective of supportive nutrition is to correct malnutrition in terms of calorie intake or specific macro- or micronutrients. Of particular clinical relevance is deficiency in calcium, vitamin D, folate, vitamin B12 and zinc. There is justifiably a growing sense of unease amongst clinicians and patients with regard to the long-term use of corticosteroids in inflammatory bowel disease. This, rather than arguments about efficacy, should be the catalyst for revisiting the use of enteral nutrition as primary treatment in Crohn's disease. Treatment failure is usually related to a failure to comply with enteral nutrition. Potential factors that militate against successful completion of enteral nutrition are feed palatability, inability to stay on a solid-free diet for weeks, social inconvenience and transient feed-related adverse reactions. Actions that can be taken to improve treatment outcome include the provision of good support from dietitians and clinicians for the duration of treatment and the subsequent 'weaning' period. There is evidence to support a gradual return to a normal diet through exclusion-re-introduction or other dietary regimen following the completion of enteral nutrition to increase remission rates. We also review the evidence for emerging therapies, such as glutamine, growth factors and short-chain fatty acids. The future may see the evolution of enteral nutrition into an important therapeutic strategy, and the design of a 'Crohn's disease-specific formulation' that is individually tailored, acceptable to patients, cost-effective, free from adverse side-effects and combines enteral nutrition with novel pre- and pro-biotics and other factors.

Therapy of Crohn's disease in childhood

Crohn's disease in childhood is a chronic relapsing and remitting condition that can significantly impact on normal growth and development. This influences the choice of both initial and ongoing management. The goal of therapy is to induce and maintain remission with minimal side effects. Enteral nutrition as the sole therapy for active disease is effective in some children, thus avoiding the use of corticosteroids. In disease that is resistant to conventional treatment, immunosuppression or anti-tumour necrosis factor therapy is indicated. We review the use of these treatments and discuss the new therapies being developed, including antibodies, cytokines and probiotics.

Enteral nutrition and corticosteroids in the treatment of acute Crohn's disease in children

BACKGROUND

The optimal treatment of acute Crohn's disease in children remains controversial. In adults, steroid therapy has been shown to be superior to exclusive enteral nutrition. However, enteral nutrition is effective at inducing a remission in many children with acute Crohn's disease. Steroid usage in children has been associated with adverse side effects, particularly with delayed growth and pubertal development.

METHODS

Randomized clinical trials comparing exclusive enteral nutrition with corticosteroids were identified. Two independent reviewers extracted data from selected studies. Studies were assessed for heterogeneity and relative risks for remission induction with enteral nutrition were obtained. Sensitivity analyses were performed in partially randomized studies. Estimates were made of the number of studies needed to overturn the current result. Other outcome measures were qualitatively assessed.

RESULTS

In five randomized clinical trials comprising 147 patients, enteral nutrition was as effective as corticosteroids at inducing a remission (RR = 0.95 [95% confidence interval 0.67, 1.34]). Addition of two further nonrandomized trials did not significantly alter the result. A minimum of 10 further studies, equal in size and outcome to the largest reported pediatric trial to date (n = 68, RR = 0.84), would be required to demonstrate a significant benefit of steroid therapy over enteral nutrition.

CONCLUSIONS

There is no difference in efficacy between enteral nutrition and corticosteroid therapy in the treatment of acute Crohn's disease in children. Improved growth and development, without the side effects of steroid therapy, make enteral nutrition a better choice for first-line therapy in children with active Crohn's disease.

Therapy of Crohn's disease in childhood

Crohn's disease in childhood is a chronic relapsing condition with a high morbidity. Growth failure is common. The aim of therapy is to induce and then maintain disease remission and thereby promote well-being and normal growth and development. Enteral nutrition (either polymeric or elemental) is effective and used as initial therapy. This is employed as sole therapy over a 6- to 8-week period followed by a period of controlled food reintroduction. The relapse rate is high and further courses of enteral nutrition or alternative therapies are frequently required. Corticosteroids are also effective as initial therapy and are required in difficult cases but there are problems with their long term use, particularly their adverse effects on growth. Many patients develop either corticosteroid-dependent or corticosteroid-resistant disease. In this instance, additional immunosuppression, such as azathioprine, can be used. Surgery is required for those patients with disease resistant to medical therapy and this will result in remission; however, the relapse rate with surgery is high. There are many areas for future research. Very little is known about why enteral nutrition works, how long it should be given or its role as maintenance therapy. Newer immunosuppressive strategies based on cytokine modulation may be helpful in children once more experience is gained from their use in adults.

Bioactive molecules in milk and their role in health and disease: the role of transforming growth factor-beta

Human breast milk is rich in nutrients, hormones, growth factors and immunoactive molecules, which influence the growth, development and immune status of the newborn infant. Although several of these factors are also present in bovine milk, the greater susceptibility of the formula-fed infant to infection and disease and the development of allergy is often attributed to the reduced level of protective factors in milk formulas. Nevertheless, modifying manufacturing processes may preserve the biological activity of some bioactive molecules in end products. Transforming growth factor (TGF)-beta is one such molecule. TGF-beta is a polypeptide, which has been described in both human and bovine milk. It is implicated in many processes, including epithelial cell growth and differentiation, development, carcinogenesis and immune regulation. The present article discusses the biological activity of TGF-beta2 that has been preserved and activated in a cow's milk-based product. More specifically, it addresses possible mechanisms of action in the intestinal lumen and speculates on how milk products containing naturally occurring TGF-beta2 could be exploited in functional foods for the infant or as therapies for specific intestinal diseases.

Nutrition in inflammatory bowel disease

The nutritional impact of inflammatory bowel disease is notable, both in Crohn's disease and ulcerative colitis. The causes of malnutrition include decreased intake, maldigestion, malabsorption, accelerated nutrient losses, increased requirements, and drug-nutrient interactions. Inflammatory bowel disease causes alterations in body composition and, because of these changes, affects energy expenditure. Various approaches have been most effective in correcting malnutrition, supporting growth, and managing short-bowel syndrome, but the success of primary therapy has been limited.

Inflammatory bowel disease in pediatric patients

The management of inflammatory bowel disease in children remains a major challenge to patients, their families, and the health care team. This review highlights the past year's advances concerning epidemiologic studies, new diagnostic considerations, and novel therapeutic approaches. Epidemiologic studies confirmed that Crohn's disease is being increasingly diagnosed in children, whereas the incidence of ulcerative colitis has remained stable. African-American children are as likely to have inflammatory bowel disease as other children. Serologic assays specific for Crohn's disease and ulcerative colitis can assist clinicians in screening for inflammatory bowel disease, as well as discriminating between the two diseases. Studies have revealed that osteopenia and antioxidant vitamin deficiency are common and require screening in pediatric inflammatory bowel disease. Increasing experience with immunosuppressive drugs (6-mercaptopurine, azathioprine) point to their efficacy and generally good toxicity profile in pediatric patients.

Nutrition in inflammatory bowel disease

Nutrition is clearly disturbed by active intestinal inflammation. Appetite is reduced, yet energy substrates are diverted into the inflammatory process, and thus weight loss is characteristic. The nutritional disturbance represents part of a profound defect of somatic function. Linear growth and pubertal development in children are notably retarded, body composition is altered, and there may be significant psychosocial disturbance. Macrophage products such as tumour necrosis factor-alpha and interleukins-1 and 6 may be the central molecules that link the inflammatory process to this derangement of homeostasis. Intriguingly, there is also increasing evidence that an aggressive nutritional programme may in itself be sufficient to reduce the mucosal inflammatory response. Recent evidence suggests that enteral nutrition alone may reduce many pro-inflammatory cytokines to normal and allow mucosal healing. In addition, specific nutritional components, such as n-3 polyunsaturated fatty acids, may have an anti-inflammatory effect as they may alter the pattern of leukotrienes generated during the immune response. The recent discovery of the specific molecular mediators of appetite and body composition, such as leptin and myostatin, may allow increased therapeutic specificity and further improvement in the nutritional treatment of the inflammatory bowel diseases.