Therapeutic approaches targeting intestinal microflora in inflammatory bowel disease

Supplementation of Crataegi fructus alleviates functional dyspepsia and restores gut microbiota in mice

Introduction

Functional dyspepsia (FD), also known as non-ulcerative dyspepsia, is a common digestive system disorder.

Methods

In this study, an FD model was established using hunger and satiety disorders combined with an intraperitoneal injection of L-arginine. Indices used to evaluate the efficacy of hawthorn in FD mice include small intestinal propulsion rate, gastric residual rate, general condition, food intake, amount of drinking water, gastric histopathological examination, and serum nitric oxide (NO) and gastrin levels. Based on the intestinal flora and their metabolites, short-chain fatty acids (SCFAs), the mechanism of action of Crataegi Fructus (hawthorn) on FD was studied. The fecal microbiota transplantation test was used to verify whether hawthorn altered the structure of the intestinal flora.

Results

The results showed that hawthorn improved FD by significantly reducing the gastric residual rate, increasing the intestinal propulsion rate, the intake of food and drinking water, and the levels of gastrointestinal hormones. Simultaneously, hawthorn elevated substance P and 5-hydroxytryptamine expression in the duodenum, reduced serum NO levels, and increased vasoactive intestinal peptide expression in the duodenum. Notably, hawthorn increased the abundance of beneficial bacteria and SCFA-producing bacteria in the intestines of FD mice, decreased the abundance of conditional pathogenic bacteria, and significantly increased the SCFA content in feces.

Discussion

The mechanism by which hawthorn improves FD may be related to the regulation of intestinal flora structure and the production of SCFAs.

Gastrointestinal microbiota and metabolites possibly contribute to distinct pathogenicity of SARS-CoV-2 proto or its variants in rhesus monkeys

Gastrointestinal (GI) infection is evidenced with involvement in COVID-19 pathogenesis caused by SARS-CoV-2. However, the correlation between GI microbiota and the distinct pathogenicity of SARS-CoV-2 Proto and its emerging variants remains unclear. In this study, we aimed to determine if GI microbiota impacted COVID-19 pathogenesis and if the effect varied between SARS-CoV-2 Proto and its variants. We performed an integrative analysis of histopathology, microbiomics, and transcriptomics on the GI tract fragments from rhesus monkeys infected with SARS-CoV-2 proto or its variants. Based on the degree of pathological damage and microbiota profile in the GI tract, five of SARS-CoV-2 strains were classified into two distinct clusters, namely, the clusters of Alpha, Beta and Delta (ABD), and Proto and Omicron (PO). Notably, the abundance of potentially pathogenic microorganisms increased in ABD but not in the PO-infected rhesus monkeys. Specifically, the high abundance of UCG-002, UCG-005, and Treponema in ABD virus-infected animals positively correlated with interleukin, integrins, and antiviral genes. Overall, this study revealed that infection-induced alteration of GI microbiota and metabolites could increase the systemic burdens of inflammation or pathological injury in infected animals, especially in those infected with ABD viruses. Distinct GI microbiota and metabolite profiles may be responsible for the differential pathological phenotypes of PO and ABD virus-infected animals. These findings improve our understanding the roles of the GI microbiota in SARS-CoV-2 infection and provide important information for the precise prevention, control, and treatment of COVID-19.

Protective Effect of Alkaline Phosphatase Supplementation on Infant Health

Alkaline phosphatase (ALP) is abundant in raw milk. Because of its high heat resistance, ALP negative is used as an indicator of successful sterilization. However, pasteurized milk loses its immune protection against allergy. Clinically, ALP is also used as an indicator of organ diseases. When the activity of ALP in blood increases, it is considered that diseases occur in viscera and organs. Oral administration or injecting ALP will not cause harm to the body and has a variety of probiotic effects. For infants with low immunity, ALP intake is a good prebiotic for protecting the infant’s intestine from potential pathogenic bacteria. In addition, ALP has a variety of probiotic effects for any age group, including prevention and treatment intestinal diseases, allergies, hepatitis, acute kidney injury (AKI), diabetes, and even the prevention of aging. The prebiotic effects of alkaline phosphatase on the health of infants and consumers and the content of ALP in different mammalian raw milk are summarized. The review calls on consumers and manufacturers to pay more attention to ALP, especially for infants with incomplete immune development. ALP supplementation is conducive to the healthy growth of infants.

Effects of Hetiao Jianpi Decoction on Intestinal Injury and Repair in Rats with Antibiotic-Associated Diarrhea

BACKGROUND Through observing the changes of indexes of the intestinal mucosal barrier and intestinal flora in rats, we explored the mechanism by which Hetiao Jianpi Decoction (HTJPD) treats antibiotic-associated diarrhea (AAD) by repairing intestinal mucosal injury and regulating intestinal flora. MATERIAL AND METHODS Samples of colon tissues were collected for HE staining. Enzyme-linked immunosorbent assay (ELISA) was used to assess levels of diamine oxidase (DAO) and D-lactic acid in rat plasma and the expression of secretory immunoglobulin A (SIgA) in colon tissue. We assessed the abundance of intestinal contents by high-throughput sequencing of the 16S rRNA gene. RESULTS Compared with the Model group, the muscle layer and intestinal mucosal edema were improved, and the continuity was restored; the levels of DAO and D-lactic acid in plasma decreased, and the SIgA level were increased in the HTJPD group. The structure of the intestinal flora changed, as indicated by increased levels of certain beneficial bacteria (Verrucomicrobia, Actinobacteria, CF231, and Akkermansia), decreased levels of pathogenic bacteria (Spirochaetes and Treponema), and increased species diversity. CONCLUSIONS By improving the permeability and immune function of the intestinal mucosa, Hetiao Jianpi decoction prevented the occurrence of AAD by repairing the intestinal mucosal damage and regulating the structure and diversity of intestinal flora.

Human intestinal spirochetosis mimicking ulcerative colitis

Human intestinal spirochetosis (HIS) is a colorectal infection caused by the Brachyspira species of intestinal spirochetes, whose pathogenicity in humans remains unclear owing to the lack of or mild symptoms. We monitored the 5-year clinical course of a woman diagnosed with HIS in whom ulcerative colitis (UC) had been suspected. Following a positive fecal occult blood test, she underwent a colonoscopic examination at a local clinic where she was diagnosed with "right-sided" UC concomitant with incidentally detected HIS, and was referred to our hospital. Colonoscopic, histopathological, and cytological examination revealed localized erosive colitis in the ascending and the right transverse colon concomitant with HIS resembling skip lesions of UC. Initially, we chose the wait-and-watch approach; however, she gradually developed bloody diarrhea. Metronidazole improved her abdominal symptoms, as well as her colonoscopic and histopathological findings, suggesting that HIS was responsible for her colorectal inflammation. This case reveals (1) a possible pro-inflammatory role of HIS, (2) difficulties in diagnosing HIS in chronic proctocolitis, and (3) a possible inclusion of some HIS cases in "UC". HIS could mimic UC and might be included in differential diagnoses for UC. Antibiotic administration is necessary following the detection of HIS, particularly in patients demonstrating an atypical presentation of UC.

Modulation of microbiota as treatment for intestinal inflammatory disorders: An uptodate

Alterations of intestinal microflora may significantly contribute to the pathogenesis of different inflammatory and autoimmune disorders. There is emerging interest on the role of selective modulation of microflora in inducing benefits in inflammatory intestinal disorders, by as probiotics, prebiotics, synbiotics, antibiotics, and fecal microbiota transplantation (FMT). To summarize recent evidences on microflora modulation in main intestinal inflammatory disorders, PubMed was searched using terms microbiota, intestinal flora, probiotics, prebiotics, fecal transplantation. More than three hundred articles published up to 2015 were selected and reviewed. Randomized placebo-controlled trials and meta-analysis were firstly included, mainly for probiotics. A meta-analysis was not performed because of the heterogeneity of these studies. Most of relevant data derived from studies on probiotics, reporting some efficacy in ulcerative colitis and in pouchitis, while disappointing results are available for Crohn's disease. Probiotic supplementation may significantly reduce rates of rotavirus diarrhea. Efficacy of probiotics in NSAID enteropathy and irritable bowel syndrome is still controversial. Finally, FMT has been recently recognized as an efficacious treatment for recurrent Clostridium difficile infection. Modulation of intestinal flora represents a very interesting therapeutic target, although it still deserves some doubts and limitations. Future studies should be encouraged to provide new understanding about its therapeutical role.

Qualitative and Quantitative Characteristics of Selected Bacterial Groups in Children with Inflammatory Bowel Diseases

The aim of the study was evaluation of qualitative and quantitative changes in bacterial ecosystem in 109 children with inflammatory bowel diseases. Stools obtained from patients were analysed for selected bacteria and concentration of faecal inflammatory markers (calprotectin, lactoferrin, M2-PK). The number of selected microorganisms depends on the level of clinical activity of disease and is correlated with faecal concentration of inflammatory markers. Differences in microflora disturbance, observed in patients with Crohn's disease and ulcerative colitis, may suggest different causes of development of both pathologies.

Flavanol-Enriched Cocoa Powder Alters the Intestinal Microbiota, Tissue and Fluid Metabolite Profiles, and Intestinal Gene Expression in Pigs

BACKGROUND

Consumption of cocoa-derived polyphenols has been associated with several health benefits; however, their effects on the intestinal microbiome and related features of host intestinal health are not adequately understood.

OBJECTIVE

The objective of this study was to determine the effects of eating flavanol-enriched cocoa powder on the composition of the gut microbiota, tissue metabolite profiles, and intestinal immune status.

METHODS

Male pigs (5 mo old, 28 kg mean body weight) were supplemented with 0, 2.5, 10, or 20 g flavanol-enriched cocoa powder/d for 27 d. Metabolites in serum, urine, the proximal colon contents, liver, and adipose tissue; bacterial abundance in the intestinal contents and feces; and intestinal tissue gene expression of inflammatory markers and Toll-like receptors (TLRs) were then determined.

RESULTS

O-methyl-epicatechin-glucuronide conjugates dose-dependently increased (P< 0.01) in the urine (35- to 204-fold), serum (6- to 186-fold), and adipose tissue (34- to 1144-fold) of pigs fed cocoa powder. The concentration of 3-hydroxyphenylpropionic acid isomers in urine decreased as the dose of cocoa powder fed to pigs increased (75-85%,P< 0.05). Compared with the unsupplemented pigs, the abundance ofLactobacillusspecies was greater in the feces (7-fold,P= 0.005) and that ofBifidobacteriumspecies was greater in the proximal colon contents (9-fold,P= 0.01) in pigs fed only 20 or 10 g cocoa powder/d, respectively. Moreover, consumption of cocoa powder reducedTLR9gene expression in ileal Peyer's patches (67-80%,P< 0.05) and mesenteric lymph nodes (43-71%,P< 0.05) of pigs fed 2.5-20 g cocoa powder/d compared with pigs not supplemented with cocoa powder.

CONCLUSION

This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance ofLactobacillusandBifidobacteriumspecies and modulating markers of localized intestinal immunity.

Anti-inflammatory effects of mannanase-hydrolyzed copra meal in a porcine model of colitis

We evaluated the anti-inflammatory activity of mannanase-hydrolyzed copra meal (MNB), including β-1,4-mannobiose (67.8%), in a dextran sodium sulfate (DSS)-induced porcine model of intestinal inflammation. In the DSS-positive control (POS) and MNB treatment (MCM) groups, DSS was first administered to piglets via intragastric catheter for 5 days, followed by 5 days administration of saline or MCM. A negative control group (NEG) received a saline alternative to DSS and MNB. Inflammation was assessed by clinical signs, morphological and histological measurements, gut permeability and neutrophil infiltration. Local production of TNF-α and IL-6 were analyzed by ELISA, colonic and ileal inflammatory gene expressions were assessed by real time RT-PCR, and CD4+CD25+ cell populations were analyzed by flow cytometry. Crypt elongation and muscle thickness, D-mannitol gut permeation, colonic expression of the inflammatory mediators TNF-α and IL-6 and myeloperoxidase activity were significantly lower in the MCM group than in that of POS group. The mRNA levels of ileal IL-1β, IL-6, IL-17 and TNF-α were significantly lower following MCM treatment than with POS treatment.MNB exerts anti-inflammatory activity in vivo, suggesting that MNB is a novel therapeutic that may provide relief to human and animals suffering from intestinal inflammation.

Three-combination probiotics therapy in children with salmonella and rotavirus gastroenteritis

GOALS

Quantitative Vesikari scales and qualitative severe diarrhea (Vesikari scale ≥11) assessments were used to grade the Salmonella-induced and rotavirus-induced gastroenteritis severity. A significant reduction in severe diarrhea (Vesikari score ≥11) was used to evaluate the efficacy of three-combination probiotics (BIO-THREE).

BACKGROUND

Several studies have shown that rotavirus and Salmonella infections are the leading causes of infectious gastroenteritis. Although probiotics have been effective in some studies, the use of 3-combination formulation probiotics is rare.

STUDY

This single-center, open-label, randomized, controlled trial included 159 patients (age range, 3 mo to 14 y) hospitalized with infectious gastroenteritis between February 2009 and October 2010.

RESULTS

Patients were grouped according to the pathogen identified (48, Salmonella; 42, rotavirus; and 69, unknown origin). The total diarrhea duration was significantly shorter for children who received BIO-THREE (P<0.0001). After BIO-THREE administration, there were significantly less intervention group patients with severe diarrhea at intervention day 3. Vesikari scale or diarrhea frequency results did not reveal significant differences between groups (except for day 5 in patients with rotavirus), and there were no significant changes in other clinical parameters or the length of hospital stay.

CONCLUSIONS

Seven-day BIO-THREE administration demonstrated high efficacy and safety in infants and children with severe gastroenteritis. The incidence of severe gastroenteritis was significantly reduced in the rotavirus origin and BIO-THREE intervention groups.

The role of intestinal alkaline phosphatase in pediatric inflammatory bowel and celiac diseases

Intestinal alkaline phosphatase enzyme plays a pivotal role in the maintenance of intestinal mucosal barrier integrity with the detoxification capacity of lipopolysaccharide, the ligand of Toll-like receptor 4. The inappropriate immune responses and the damage of the mucosal barrier may contribute to the initiation of inflammatory bowel and celiac diseases. In the inflamed colonic mucosa of children with inflammatory bowel disease and in the duodenal mucosa of newly diagnosed children with celiac disease, the decreased intestinal alkaline phosphatase and increased Toll-like receptor 4 protein expression may generate enhanced lipopolysaccharide activity, which may strengthen tissue damaging processes. The enhancement of intestinal alkaline phosphatase activity in an animal model of colitis and in therapy resistant, adult patients with ulcerative colitis reduced the symptoms of intestinal inflammation. In accordance with these results, the targeted intestinal administration of the enzyme in the two examined disorders may be a supplemental therapeutic option in the future. Orv. Hetil., 2012, 153, 1389–1395.

Probiotics prevent growth deficit of colon wall strata of malnourished rats post-lactation

The objective of this study was to analyze morphometrically the colon wall strata of malnourished rats supplemented with probiotics. Sixteen recently weaned Wistar rats (Rattus norvegicus) were distributed into four groups: animals that received commercial chow (G1, n = 4); animals that received the same feed as G1 and were supplemented with probiotics (G2, n = 4); animals that received chow with 4% of proteins (G3, n = 4); animals that received the same feed as G3 and were supplemented with probiotics (G4, n = 4). After 12 weeks, the proximal colon was collected and submitted to histological processing. Three-µm cuts were stained with H.E., Periodic Acid Schifff (P.A.S.) + diasthasis solution and Alcian Blue (A.B.) pH 2.5 and pH 1.0. The morphometric analysis of the intestinal wall showed that the supplementation with ABT-4 probiotic culture prevents the growth deficit of colon wall strata that normally occurs in malnourished rats right after lactation. Besides, no alteration was observed in the proportion of the number of globet cells in relation to the number of enterocytes in malnourished rats, regardless of the supplementation with probiotics.

Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease

AIM: To investigate intestinal alkaline phosphatase (iAP) in the intestinal mucosa of children with inflammatory bowel disease (IBD).

METHODS: Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtained both from inflamed and non-inflamed areas. The iAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localization of iAP and Toll-like receptor (TLR) 4 was investigated by immunofluorescent staining.

RESULTS: The iAP protein level in the inflamed mucosa of children with Crohn’s disease (CD) and ulcerative colitis (UC) was significantly decreased when compared with controls (both P < 0.05). Similarly, we found a significantly decreased level of iAP protein in the inflamed mucosa in CD compared with non-inflamed mucosa in CD (P < 0.05). In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD (P < 0.05). iAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls. iAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significantly different from that in non-inflamed colonic mucosa with CD. Expression of iAP mRNA in patients with non-inflamed mucosa and in controls were similar. Co-localization of iAP with TLR4 showed intense staining with a dotted-like pattern. iAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. However, the fluorescent signal of TLR4 was more pronounced in the colon compared with the terminal ileum in all groups studied.

CONCLUSION: Lower than normal iAP protein levels in inflamed mucosa of IBD patients may indicate a role for iAP in inflammatory lesions in IBD. Based on our results, administration of exogenous iAP enzyme to patients with the active form of IBD may be a therapeutic option.

The human microbiome and its potential importance to pediatrics

The human body is home to more than 1 trillion microbes, with the gastrointestinal tract alone harboring a diverse array of commensal microbes that are believed to contribute to host nutrition, developmental regulation of intestinal angiogenesis, protection from pathogens, and development of the immune response. Recent advances in genome sequencing technologies and metagenomic analysis are providing a broader understanding of these resident microbes and highlighting differences between healthy and disease states. The aim of this review is to provide a detailed summary of current pediatric microbiome studies in the literature, in addition to highlighting recent findings and advancements in studies of the adult microbiome. This review also seeks to elucidate the development of, and factors that could lead to changes in, the composition and function of the human microbiome.

Changes in immunohistochemical levels and subcellular localization after therapy and correlation and colocalization with CD68 suggest a pathogenetic role of Hsp60 in ulcerative colitis

In an earlier work, the role of heat shock protein (Hsp60) in the pathogenesis of ulcerative colitis (UC) was suggested by its significant increase in the pathological mucosa parallel with an increase in inflammatory cells. More data in this direction are reported in this work. We analyzed by immunohistochemistry biopsies of colon tissue from 2 groups of patients with UC and treated with either 5-aminosalicylic acid (5-ASA) alone or in combination with a probiotic. We looked for inflammatory markers and Hsp60. Both the treatments were effective in reducing symptoms but the group treated with both 5-ASA and probiotics showed better clinical results. Amelioration of symptoms was associated with reduction of both inflammation and Hsp60, a reduction that was most marked in the group treated with 5-ASA and probiotics. The levels of Hsp60 positively correlated with those of CD68-positive cells, and double immunofluorescence showed a high index of colocalization of the chaperonin and CD68 in lamina propria. Immunoelectron microscopy showed that Hsp60-classically a mitochondrial protein-was abundantly also present in cytosol in biopsies taken at the time of diagnosis, but not after the treatment. Our data suggest that Hsp60 is an active player in pathogenesis of UC and it can be hypothesized that the chaperonin is responsible, at least in part, for initiation and maintenance of disease.

Lactobacillus plantarum lipoteichoic acid down-regulated Shigella flexneri peptidoglycan-induced inflammation

Bacterial peptidoglycans (PGNs) are recognized by the host's innate immune system. This process is mediated by the NOD/CARD family of proteins, which induces inflammation by activating nuclear factor (NF)-κB. Excessive activation of monocytes by Shigella flexneri PGN (flexPGN) leads to serious inflammatory diseases such as intestinal bowel diseases (IBD) and Crohn's disease. In this study, we examined whether Lactobacillus plantarum lipoteichoic acid (pLTA) could attenuate the pro-inflammatory signaling induced by flexPGN in human monocytic THP-1 cells. Compared to control THP-1 cells, pLTA-tolerant cells showed a significant reduction in TNF-α and IL-1β production in response to flexPGN. We also examined the inhibition of NF-κB and the activation of mitogen-activated protein kinase (MAPK) in pLTA-tolerant cells. We found that the expression of NOD2 in pLTA-tolerant cells was down-regulated at the mRNA and protein levels, suggesting that pLTA is a potent modulator of the pro-inflammatory NOD2-related signaling pathways induced by flexPGN. Together, these data indicate that pLTA induces cross-tolerance against flexPGN. Notably, these effects are related not only to IL-1 signaling, which is known to play a role in LPS tolerance, but also to NOD-Rick signaling. This study provides insight into how commensal microflora may contribute to homeostasis of the host intestinal tract.

Probiotics and prebiotics in animal feeding for safe food production

Recent outbreaks of food-borne diseases highlight the need for reducing bacterial pathogens in foods of animal origin. Animal enteric pathogens are a direct source for food contamination. The ban of antibiotics as growth promoters (AGPs) has been a challenge for animal nutrition increasing the need to find alternative methods to control and prevent pathogenic bacterial colonization. The modulation of the gut microbiota with new feed additives, such as probiotics and prebiotics, towards host-protecting functions to support animal health, is a topical issue in animal breeding and creates fascinating possibilities. Although the knowledge on the effects of such feed additives has increased, essential information concerning their impact on the host are, to date, incomplete. For the future, the most important target, within probiotic and prebiotic research, is a demonstrated health-promoting benefit supported by knowledge on the mechanistic actions. Genomic-based knowledge on the composition and functions of the gut microbiota, as well as its deviations, will advance the selection of new and specific probiotics. Potential combinations of suitable probiotics and prebiotics may prove to be the next step to reduce the risk of intestinal diseases and remove specific microbial disorders. In this review we discuss the current knowledge on the contribution of the gut microbiota to host well-being. Moreover, we review available information on probiotics and prebiotics and their application in animal feeding.

Cellobiose Prevents the Development of Dextran Sulfate Sodium (DSS)-Induced Experimental Colitis

Cellobiose is produced from cellulose using specific bacterial enzymes, and is hydrolyzed into glucose by the enzymes cellobiosidase and cellulase. In this study, we examined the effects of cellobiose on colonic mucosal damage in a dextran sulfate sodium (DSS) colitis model. BALB/c mice were divided into two groups. In the first group, the mice were fed 3.5% DSS mixed with normal chow. In the second group, the mice were fed 3.5% DSS plus 6.0 or 9.0% (weight/weight) cellobiose mixed with normal chow. The development of colitis was assessed on day 21. Mucosal cytokine expression was analyzed by RT-PCR. Body weight loss was significantly attenuated in the 9.0% cellobiose-fed DSS mice as compared to the DSS mice. Colonic weight/length ratio, a maker of tissue edema, was significantly higher in the DSS mice than in the 9.0% cellobiose-fed DSS mice. The disease activity index and histological colitis score were also significantly higher in the DSS mice than in the 9.0% cellobiose-fed DSS mice. Mucosal mRNA expression for IL-1β, TNF-α, IL-17 and IP-10 were markedly reduced in the 9.0% cellobiose-fed DSS mice. In conclusion, a preventive effect of cellobiose against DSS colitis suggests its clinical use for inflammatory bowel diseases patients.

Prevention of TNBS-induced colitis by different Lactobacillus and Bifidobacterium strains is associated with an expansion of gammadeltaT and regulatory T cells of intestinal intraepithelial lymphocytes

BACKGROUND

Probiotics may protect against inflammatory bowel disease through regulation of lamina propria lymphocytes (LPLs) function. Data are lacking on possible involvement of intraepithelial lymphocytes (IELs). The aim of this study was to investigate whether different probiotic mixtures prevented gut inflammatory disease and the role of both IELs and LPLs.

METHODS

BALB/c mice received 2 probiotic mixtures orally for 3 weeks, as Mix1 (Lactobacillus acidophilus and Bifidobacterium longum), or Mix2 (Lactobacillus plantarum, Streptococcus thermophilus, and Bifidobacterium animalis subsp. lactis). Colitis was induced by intrarectal administration of trinitrobenzene sulfonic acid (TNBS). Probiotics in stools were analyzed by real-time polymerase chain reaction (PCR). Colon subpopulations of IELs and LPLs were assayed by flow cytometry. Serum cytokines were measured by cytometric bead array (CBA).

RESULTS

All probiotics colonized the intestine. The 2 mixtures prevented the TNBS-induced intestinal damage, and Mix1 was the most effective. The Mix1 protection was associated with a reduction in CD4(+) cells of IELs and LPLs, an increase in gammadeltaT cells of IELs, and a decrease in gammadeltaT cells of LPLs. An expansion of T regulatory (Treg) cells of IELs was induced by Mix1 and Mix2. Both probiotic mixtures inhibited tumor necrosis factor (TNF)-alpha and monocyte chemotactic protein (MCP)-1 production and upregulated interleukin (IL)-10. In addition, Mix1 prevented the TNBS-induced increase of IL-12 and interferon (IFN)-gamma.

CONCLUSIONS

The 2 probiotic mixtures were able to prevent the TNBS-induced colitis; the L. acidophilus and B. longum mixture was the most effective. Other than an involvement of LPLs, our results report a novel importance of the IELs population in probiotic protection.

Prebiotics in chronic intestinal inflammation

Prebiotics are nondigestible fermentable fibers that are reported to have health benefits for the host. Older as well as more recent studies show beneficial effects in experimental colitis and lately also in human inflammatory bowel diseases (IBD), such as Crohn's disease, ulcerative colitis, and chronic pouchitis. In this review we give an overview of the benefits of prebiotics in rodent IBD models and in IBD patients and discuss their possible protective mechanisms. Commensal intestinal bacteria induce and perpetuate chronic intestinal inflammation, whereas others are protective. However, most of the current medications are directed against the exaggerated proinflammatory immune response of the host, some of them toxic and costly. Feeding prebiotics changes the composition of the intestinal microflora toward more protective intestinal bacteria and alters systemic and mucosal immune responses of the host. Therapy for IBD targeting intestinal bacteria and their function is just emerging. Prebiotics have the promise to be relatively safe, inexpensive, and easy to administer. Unraveling their protective mechanisms will help to develop rational applications of prebiotics. However, the initial promising results with dietary prebiotics in preclinical trials as well as small studies in human IBD will need to be confirmed in large randomized controlled clinical trials.

Obesity, innate immunity and gut inflammation

PURPOSE OF REVIEW

The purpose of this review is to present recent data on how obesity-associated conditions may affect innate immunity and its role in the development of gut inflammation.

RECENT FINDINGS

Here we present studies that demonstrate the participation of adipose tissue components in the generation of inflammation. More specifically, we describe increases in the release of proinflammatory cytokines during obesity as well as the expression of receptors involved in innate immune responses by adipocytes. Furthermore, we present data on the involvement of adipose tissue-specific molecules (adipokines) in the generation of an environment that is favorable for diseases with an immune cause and in some cases (leptin) directly contribute to the development of inflammatory bowel disease. Finally, we present evidence supporting a putative association between obesity and gut inflammation through the link of inflammation with angiogenesis and neovascularization and the favorable conditions created for these responses in obesity.

SUMMARY

We believe that obesity-related systemic changes may create conditions that predispose to the development of gut inflammation or even worsen the progression of ongoing disease.