Intestinal homeostasis is restored in mice following a period of intestinal growth induced by orally administered Emu Oil.

Previously, we reported that orally administered Emu Oil (EO) increases mucosal thickness in the small intestine and colon in rodent models of chemotherapy-induced mucositis and colitis. However, it remains unclear whether mucosal thickening (crypt and villus lengthening) represents a process of normal or aberrant growth. We sought to determine if villus height (VH) and crypt depth (CD) measurements returned to normal in EO-treated rats following withdrawal of EO therapy. Dark agouti rats ( n = 8/group) were gavaged daily for 10 days with water, olive oil (OO), or EO (0.5 mL or 1 mL). Groups of rats were euthanized on days 10 and 17. Intestinal weights, lengths, VH, and CD were quantified. P < 0.05 was considered significant. On day 10, jejuno-ileum weight was increased by OO (26%) and EO (0.5 mL: 15%; 1 mL: 29%) compared to water controls ( P < 0.01), which was normalized by day 17. On days 10 and 17, jejuno-ileum length was greater in OO- (12%) and EO-treated rats (0.5 mL: 8%; 1 mL: 12%; P < 0.05), relative to water controls. On day 10, OO and EO increased ileal VH (OO: 32%; 0.5 EO: 22%; EO: 35%; P < 0.01) and CD (OO: 17%; 0.5 EO: 13%; EO: 22%) compared to water controls. Importantly, however, after withdrawal of all oils, VH and CD measurements returned to normal control values. Moreover, the VH:CD ratio (potential indicator of dysplasia) remained unchanged in all experimental groups on days 10 and 17. The restoration of normal intestinal architecture following cessation of Emu Oil therapy supports its safety for application in intestinal disorders. Impact statement Uncontrolled inflammation and intestinal proliferation can predispose to the development of colorectal cancer. In previous pre-clinical studies, we demonstrated that oral administration of Emu Oil promotes intestinal repair via stimulation of the mucosa in response to tissue injury and inflammation. Therefore, it was important to determine if Emu Oil administration did not promote the precocious development of colorectal cancer. The current study revealed that Emu Oil returned indicators of intestinal proliferation back to normal values after a period of seven days. These data strongly support the safety of Emu Oil for further studies in the context of bowel inflammation.

A Judgement Bias Test to Assess Affective State and Potential Therapeutics in a Rat Model of Chemotherapy-Induced Mucositis.

Chemotherapy-induced mucositis is an extremely painful condition that occurs in 40-60% of patients undergoing chemotherapy. As mucositis currently has no effective treatment, and due to the self-limiting nature of the condition, the major treatment aims are to manage symptoms and limit pain with significance placed on improving patient quality of life. Rodent models are frequently used in mucositis research. These investigations typically assess pathological outcomes, yet fail to include a measure of affective state; the key therapeutic goal. Assessment of cognitive biases is a novel approach to determining the affective state of animals. Consequently, this study aimed to validate a cognitive bias test through a judgement bias paradigm to measure affective state in a rat model of chemotherapy-induced intestinal mucositis. Rats with intestinal mucositis demonstrated a negative affective state, which was partially ameliorated by analgesic administration, whilst healthy rats showed an optimistic response. This study concluded that the judgement bias test was able to evaluate the emotional state of rats with chemotherapy-induced mucositis. These findings provide a foundation for future refinement to the experimental design associated with the animal model that will expedite successful transitioning of novel therapeutics to clinical practice, and also improve humane endpoint implementation.

Rhubarb extract partially improves mucosal integrity in chemotherapy-induced intestinal mucositis.

AIM: To investigate the effects of orally gavaged aqueous rhubarb extract (RE) on 5-fluorouracil (5-FU)-induced intestinal mucositis in rats. METHODS: Female Dark Agouti rats (n = 8/group) were gavaged daily (1 mL) with water, high-dose RE (HDR; 200 mg/kg) or low-dose RE (LDR; 20mg/kg) for eight days. Intestinal mucositis was induced (day 5) with 5-FU (150 mg/kg) via intraperitoneal injection. Intestinal tissue samples were collected for myeloperoxidase (MPO) activity and histological examination. Xenopus oocytes expressing aquaporin 4 water channels were prepared to examine the effect of aqueous RE on cell volume, indicating a potential mechanism responsible for modulating net fluid absorption and secretion in the gastrointestinal tract. Statistical significance was assumed at P < 0.05 by one-way ANOVA. RESULTS: Bodyweight was significantly reduced in rats administered 5-FU compared to healthy controls (P < 0.01). Rats administered 5-FU significantly increased intestinal MPO levels (≥ 307%; P < 0.001), compared to healthy controls. However, LDR attenuated this effect in 5-FU treated rats, significantly decreasing ileal MPO activity (by 45%; P < 0.05), as compared to 5-FU controls. 5-FU significantly reduced intestinal mucosal thickness (by ≥ 29% P < 0.001) as compared to healthy controls. LDR significantly increased ileal mucosal thickness in 5-FU treated rats (19%; P < 0.05) relative to 5-FU controls. In xenopus oocytes expressing AQP4 water channels, RE selectively blocked water influx into the cell, induced by a decrease in external osmotic pressure. As water efflux was unaltered by the presence of extracellular RE, the directional flow of water across the epithelial barrier, in the presence of extracellular RE, indicated that RE may alleviate water loss across the epithelial barrier and promote intestinal health in chemotherapy-induced intestinal mucositis. CONCLUSION: In summary, low dose RE improves selected parameters of mucosal integrity and reduces ileal inflammation, manifesting from 5-FU-induced intestinal mucositis.

Emu Oil Combined with Lyprinol™ Reduces Small Intestinal Damage in a Rat Model of Chemotherapy-Induced Mucositis.

Chemotherapy-induced mucositis is characterized by inflammation and ulcerating lesions lining the alimentary tract. Emu Oil and Lyprinol™ have independently demonstrated their therapeutic potential in intestinal inflammatory disorders, including mucositis. We investigated Emu Oil and Lyprinol™ in combination for their further potential to alleviate chemotherapy-induced mucositis in rats. Rats were gavaged with (1 ml) water, Olive Oil, Emu Oil + Olive Oil, Lyprinol™ + Olive Oil or Emu Oil + Lyprinol™ from Days 0 to 7, injected with saline (control) or 5-Fluorouracil (5-FU) on Day 5 and euthanized on Day 8. Myeloperoxidase (MPO) activity (indicative of acute inflammation), histological severity scores, and intestinal architecture were quantified. Myeloperoxidase activity was significantly increased in the jejunum and ileum following 5-FU, compared to saline controls. Both Olive Oil and Emu Oil + Lyprinol™ significantly reduced jejunal MPO levels (1.8-fold and 1.7-fold, respectively), whereas only Emu Oil + Lyprinol™ significantly decreased ileal MPO levels, relative to 5-FU controls. All oil treatments decreased histological severity scores in the jejunum and ileum, and normalized crypt depth in the mid small intestine, relative to 5-FU controls. Emu Oil combined with Lyprinol™ partially reduced acute small intestinal inflammation. Isolating bioactive constituents of these naturally sourced oils could provide a more targeted strategy to protect against intestinal mucositis.

Differential Effectiveness of Clinically-Relevant Analgesics in a Rat Model of Chemotherapy-Induced Mucositis.

Chemotherapy-induced intestinal mucositis is characterized by pain and a pro-inflammatory tissue response. Rat models are frequently used in mucositis disease investigations yet little is known about the presence of pain in these animals, the ability of analgesics to ameliorate the condition, or the effect that analgesic administration may have on study outcomes. This study investigated different classes of analgesics with the aim of determining their analgesic effects and impact on research outcomes of interest in a rat model of mucositis. Female DA rats were allocated to 8 groups to include saline and chemotherapy controls (n = 8). Analgesics included opioid derivatives (buprenorphine; 0.05mg/kg and tramadol 12.5mg/kg) and NSAID (carprofen; 15mg/kg) in combination with either saline or 5-Fluorouracil (5-FU; 150mg/kg). Research outcome measures included daily clinical parameters, pain score and gut histology. Myeloperoxidase assay was performed to determine gut inflammation. At the dosages employed, all agents had an analgesic effect based on behavioural pain scores. Jejunal myeloperoxidase activity was significantly reduced by buprenorphine and tramadol in comparison to 5-FU control animals (53%, p = 0.0004 and 58%, p = 0.0001). Carprofen had no ameliorating effect on myeloperoxidase levels. None of the agents reduced the histological damage caused by 5-FU administration although tramadol tended to increase villus length even when administered to healthy animals. These data provide evidence that carprofen offers potential as an analgesic in this animal model due to its pain-relieving efficacy and minimal effect on measured parameters. This study also supports further investigation into the mechanism and utility of opioid agents in the treatment of chemotherapy-induced mucositis.

Effects of Metabolic Cage Housing on Rat Behavior and Performance in the Social Interaction Test.

Although the metabolic cage is commonly used for housing nonhuman animals in the laboratory, it has been recognized as constituting a unique stressor. Such an environment would be expected to affect behavioral change in animals housed therein. However, few studies have specifically addressed the nature or magnitude of this change. The current study sought to characterize the behavioral time budget of rats in metabolic cage housing in comparison to that of individually housed animals in standard open-top cages. Rats in metabolic cages spent less time moving, manipulating enrichment, and carrying out rearing behaviors, and there was a corresponding shift toward inactivity. In an applied Social Interaction Test, behavioral scoring implied that metabolic cage housing had an anxiogenic effect. In conclusion, metabolic cage housing produces measurable effects on spontaneous and evoked behavior in rats in the laboratory. These behavioral changes may lead to a negative emotional state in these animals, which could have negative welfare consequences. Further research is needed to quantify the existence and magnitude of such an effect on rat well being.

Oral Nucleotides Only Minimally Improve 5-Fluorouracil-Induced Mucositis in Rats.

Chemotherapy-induced mucositis is characterized by inflammation and ulceration of the intestinal mucosa, compromising intestinal function. Exogenous nucleotides have been reported to repair the mucosa. The nucleotide preparation, Nucleoforce F0328 (Nucleoforce), was investigated for its potential to ameliorate intestinal mucositis in rats. Female Dark Agouti rats (n = 8/group) were gavaged once daily with Nucleoforce (175 mg/kg) or water from Days 0 to 8 and injected (i.p.) with 5-fluorouracil (5-FU; 150 mg/kg) or saline on Day 5. Histological parameters (disease severity, crypt depth, and villus height measurements) and myeloperoxidase activity were quantified. P < 0.05 was considered significant. Jejunal and ileal histological disease severity scores were significantly increased by 5-FU, compared to normal controls (P < 0.05). Nucleoforce treatment in 5-FU-injected rats significantly reduced jejunal and ileal disease severity compared to 5-FU controls (P < 0.05). In 5-FU-injected rats, jejunal and ileal villus heights and crypt depths were significantly decreased compared to 5-FU controls, with no additional Nucleoforce effect (P > 0.05). Intestinal myeloperoxidase activity was significantly elevated by 5-FU (8.8-fold), compared to normal controls (P < 0.05), which was not normalized by Nucleoforce treatment (P > 0.05). Nucleoforce only partially improved parameters associated with experimentally-induced mucositis. Future studies could investigate increased concentrations, more frequent administration, or protective microencapsulation delivery methods, to increase bioavailability.

Clinical and structural effects of traditional Chinese medicine and the herbal preparation, Iberogast, in a rat model of ulcerative colitis.

Plant-sourced formulations such as Iberogast and the traditional Chinese medicine formulation, Cmed, purportedly possess anti-inflammatory and radical scavenging properties. We investigated Iberogast and Cmed, independently, for their potential to decrease the severity of the large bowel inflammatory disorder, ulcerative colitis. Sprague Dawley rats (n = 8/group) received daily 1 mL gavages (days 0-13) of water, Iberogast (100 µL/200 µL), or Cmed (10 mg/20 mg). Rats ingested 2% dextran sulfate sodium or water ad libitum for 7 days commencing on day 5. Dextran sulfate sodium administration increased disease activity index scores from days 6 to 12, compared with water controls (P < .05). On day 10, 200 µL Iberogast decreased disease activity index scores in colitic rats compared with colitic controls (P < .05). Neither Iberogast nor Cmed achieved statistical significance for daily metabolic parameters or colonic crypt depth. The therapeutic effects of Iberogast and Cmed were minimal in the colitis setting. Further studies of plant extracts are required investigating greater concentrations and alternative delivery systems.

Grape seed extract reduces the severity of selected disease markers in the proximal colon of dextran sulphate sodium-induced colitis in rats.

BACKGROUND: Grape seed extract (GSE) constitutes a rich source of procyanidins. GSE has been demonstrated to exert encouraging anti-inflammatory and anti-ulcer properties in experimental settings, although its effects on inflammation of the colon remain undefined. AIM: To determine the effects of GSE in a rat model of dextran sulphate sodium (DSS) for ulcerative colitis. METHODS: Male Sprague-Dawley rats were gavaged daily (days 0-10) with GSE (400 mg/kg). Ulcerative colitis was induced by substituting DSS (2 % w/v) for drinking water from days 5-10. A sucrose breath test was performed on day 11 to determine small bowel function and intestinal tissues were collected for histological analyses. Statistical analysis was by one-way or repeated-measures ANOVA and p < 0.05 was considered significant. RESULTS: Compared to DSS-treated controls, GSE significantly decreased ileal villus height (14 %; p < 0.01) and mucosal thickness (13 %; p < 0.01) towards the values of normal controls. GSE reduced qualitative histological severity score (p < 0.05) in the proximal colon, although no significant effect was evident in the distal colon. However, GSE failed to prevent DSS-induced damage to the crypts of both colonic regions. Administration of GSE did not negatively impact metabolic parameters, nor did it induce any deleterious gastrointestinal side effects in healthy animals. CONCLUSIONS: GSE decreased the severity of selected markers of DSS-induced colitis in the distal ileum and proximal colon, suggesting the potential as an adjuvant therapy for the treatment of ulcerative colitis. Future studies of GSE should investigate alternative delivery methods and treatment regimens, further seeking to identify the individual bioactive factors.

Early oral ovalbumin exposure during maternal milk feeding prevents spontaneous allergic sensitization in allergy-prone rat pups.

There are conflicting data to support the practice of delaying the introduction of allergenic foods into the infant diet to prevent allergy development. This study investigated immune response development after early oral egg antigen (Ovalbumin; OVA) exposure in a rat pup model. Brown Norway (BN) rat pups were randomly allocated into groups: dam reared (DR), DR pups challenged daily (days 4-13) with oral OVA (DR + OVAc), DR pups challenged intermittently (on day 4, 10, 12, and 13) with oral OVA (DR + OVAi), formula-fed pups (FF), and FF pups challenged daily with oral OVA (FF + OVA). Immune parameters assessed included OVA-specific serum IgE, IgG1, and IgA. Ileal and splenic messenger ribonucleic acid (mRNA) expression of transforming growth factor-beta (TGF-ß1), mothers against decapentaplegic (Smad) 2/4/7, and forkhead box P3 (Foxp3) were determined. Ileum was stained for TGF-ß1 and Smad4. Results. Feeding OVA daily to DR pups maintained systemic and local gut antibody and immunoregulatory marker mRNA responses. Systemic TGF-ß1 was lower in DR + OVAi pups compared to DR and DR + OVAc pups. Feeding OVA to FF pups resulted in significantly greater OVA-specific IgE and IgG1, and lower IgA and TGF-ß1 and Smad expression compared to DR pups. Conclusions. Early daily OVA exposure in the presence of maternal milk maintains immune markers associated with a regulated immune response, preventing early allergic sensitization.

Oral ingestion of Streptococcus thermophilus does not affect mucositis severity or tumor progression in the tumor-bearing rat.

Preventative or adjunctive agents for the amelioration of small intestinal chemotherapy-induced mucositis are not currently available for clinical use. We have previously demonstrated that oral ingestion of Streptococcus thermophilus (TH-4) partially attenuated chemotherapy-induced mucositis in the rat. Here we assess the effects of TH-4 on small intestinal damage and tumor progression in tumor-bearing rats with experimentally-induced mucositis. Female Dark Agouti tumor-bearing (mammary adenocarcinoma) rats (n = 36; 139 ± 1 g) had small intestinal damage induced via the administration of methotrexate (MTX). Rats were administered MTX; (1.5 mg/kg intramuscular) or saline at 0 and 24 h; with daily gavage administration of TH-4 (109 cfu/mL) or skim milk from -48 to +96 h post-MTX. Rats were allocated to groups (n=9): saline control, TH-4 control, MTX control or TH-4+MTX. The non-invasive ( 13) C-sucrose breath test (SBT) was conducted prior to tumor inoculation, pre-MTX (-24 h) and prior to sacrifice (96 h) to monitor gut function. At sacrifice small intestinal segments were excised and assessed for sucrase and myeloperoxidase activity as well as histological damage. Irrespective of TH-4 treatment, MTX-treated rats had a significant decrease in bodyweight, SBT levels, sucrase and myeloperoxidase activity, and histological damage score (p < 0.05) compared to saline and TH-4 control rats. TH-4 treatment did not result in tumor progression (p > 0.05) but failed to alleviate mucositis indices. Although TH-4, at a dose of 109 cfu/mL, yielded neither protection nor amelioration of chemotherapy-induced mucositis, progression of mammary adenocarcinoma was unaffected.

Maternal milk, but not formula, regulates the immune response to beta-lactoglobulin in allergy-prone rat pups.

Controversy exists regarding the timing of the introduction of allergic foods into the diet. We investigated the immune response of rat pups exposed to beta-lactoglobulin (BLG), one of the main allergenic proteins in cow milk. Brown Norway allergy-prone rats were allocated into groups: dam-reared and unchallenged (DR), DR challenged with BLG via gavage (11 mg/d), or rats fed via gastric cannula a formula containing BLG (11 mg/d). BLG was given from d 4 of life. Rats were killed at d 10, 14, or 21. Sera were assayed for total IgE, BLG-specific IgG1, and rat mucosal mast cell protease II (RMCPII; indicator of mucosal mast cell degranulation). Ileum was assessed for cytokine mRNA. Mesenteric lymph nodes (MLN) were assessed for forkhead boxP3 (Foxp3) and chemokine (C-C motif) receptor 7 (CCR7) expression by real-time PCR and immunostained for Foxp3(+) CD4(+) regulatory cells. Formula feeding compared with dam-rearing with or without oral BLG challenge resulted in significantly greater serum IgE, BLG-specific IgG1, RMCPII, and intestinal mast cells but reduced MLN Foxp3(+) cells, Foxp3, and CCR7 expression and ileal cytokines, interleukin (IL)-4, IL-10, and interferon-gamma (P < 0.05). Importantly, giving BLG in the presence of maternal milk resulted in an immune response profile similar to that of unchallenged DR rats but with greater Foxp3 and CCR7 mRNA expression and CD4(+) Foxp3(+) cells (P < 0.05). We conclude that introducing an allergenic food with breast milk reduces immunological indicators of an allergic response, whereas introduction during formula feeding generates an allergic response.

Effects of Streptococcus thermophilus TH-4 on intestinal mucositis induced by the chemotherapeutic agent, 5-Fluorouracil (5-FU).

Beneficial bacteria (probiotics) and probiotic-derived factors have the potential to ameliorate disorders of the intestine. The aim of this study was to compare live Streptococcus thermophilus TH-4 (TH-4), dead TH-4 and TH-4 supernatant in rats treated with 5-Fluorouracil. Rats were randomly allocated to five treatment groups (n=8-10): Saline+Water; 5-FU+Skim Milk; 5-FU+Live TH-4; 5-FU+Supernatant TH-4; and 5-FU+Dead TH-4. 5-FU (150mg.kg(-1)) was administered by a single intraperitoneal injection on day 0; animals were killed on day 4. Treatments were administered daily from days -2 to 3 via oro-gastric gavage. Metabolic parameters were measured daily. Blood was obtained by cardiac puncture, and intestinal tissues removed for quantitative and qualitative histological assessment, including: villous height and area; crypt depth and area, mitotic count and crypt fission; biochemical determination of sucrase and myeloperoxidase (MPO) activity; and disease severity scoring. One-way ANOVA statistical analyses were conducted for the majority of outcome measures. Live TH-4 significantly reduced disease severity score by 13% (p< 0.05), and partially normalised mitotic counts compared with 5-FU+Skim milk controls. Live and supernatant TH-4 reduced crypt fission by 69% and 48% (p< 0.05), respectively, compared to 5-FU+Skim Milk controls. No significant differences (p> 0.05) in the occurrence of bacteraemia were evident across all groups. Live TH-4 partially normalised mitotic count and histological severity score in 5-FU treated rats. The inhibitory effect of live TH-4 and TH-4 supernatant on crypt fission suggests therapeutic utility in the prevention of disorders characterised by increased crypt fission, such as colorectal carcinoma.

The herbal extract, Iberogast, improves jejunal integrity in rats with 5-Fluorouracil (5-FU)-induced mucositis.

There is an acute need for the development of effective therapies for mucositis, a debilitating side effect of cancer chemotherapy. Iberogast is a herbal extract reported to possess anti-inflammatory properties. We investigated Iberogast for its potential to reduce the severity of 5-Fluorouracil (FU)-induced mucositis in rats. Rats were allocated to three treatment groups (n = 8) and gavaged daily with a 10% solution of Iberogast or water from day 0 to day 8. Rats were injected intraperitoneally with 5-FU (150 mg/kg) or saline on day 6, and killed after 72 h. In vivo and in vitro sucrase activity was assessed by (13)C-sucrose breath test (SBT) and sucrase assay respectively. Intestinal disease severity was determined by histological assessment of villus height and crypt depth. Significant increases in villus height (277 +/- 9 microm) and crypt depth (67 +/- 3 microm) were observed in 5-FU + Iberogast-treated rats compared with 5-FU + Water (224 +/- 13 microm and 48 +/- 2 microm respectively; p < 0.05). Sucrase activity was significantly reduced in all 5-FU groups compared to control. Significant reductions in SBT and sucrase activity were observed in all 5-FU groups compared with Saline + Water controls (p < 0.05). We conclude that although Iberogast partially improved the histopathological features of 5-FU induced mucositis, it conferred no significant protection as indicated by the assessed endpoints.

Gastrointestinal pathology in a mouse model of mucopolysaccharidosis type IIIA.

Mucopolysaccharidosis type IIIA (MPS IIIA) is a lysosomal storage disorder caused by a deficiency in sulphamidase (NS), a lysosomal enzyme required for the degradation of heparan sulphate glycosaminoglycans (gags). The MPS IIIA mouse is a naturally occurring model that accurately reflects the human pathology and disease course. It displays primarily central nervous system pathology accompanied by widespread accumulation of gag in somatic tissues. MPS IIIA mice exhibit greater bodyweight gain than normal littermates and attain a higher mature bodyweight. In this study, gastrointestinal morphology and function was characterised in the IIIA mouse. Stomach and duodenum weight increased in MPS IIIA mice and duodenum length also increased. An increased submucosal thickness was observed in MPS IIIA intestine compared to normal mice and lysosomal storage of gag was observed in this region. Storage was also observed in the lamina propria of the villus tip. All other morphometric measurements including villus height and crypt depth fell within the normal range. The gastric emptying half-life of solid and liquid meals decreased with age in normal mice whereas the T(1/2) of solid meals did not alter with age in MPS IIA mice such that they were elevated above normal by 38 weeks of age. Sucrase activity was higher than normal in MPS IIIA at all ages tested. These abnormalities in GI structure and function observed in MPS IIIA may contribute to weight gain in this disorder.

Effects of Streptococcus thermophilus TH-4 on intestinal mucositis induced by the chemotherapeutic agent 5-Fluorouracil (5-FU).

Beneficial bacteria (probiotics) and probiotic-derived factors have the potential to ameliorate disorders of the intestine. The aim of this study was to compare live Streptococcus thermophilus TH-4 (TH-4), dead TH-4 and TH-4 supernatant in rats treated with 5-Fluorouracil. Rats were randomly allocated to five treatment groups (n = 8­10): Saline + Water; 5-FU + Skim Milk; 5-FU+ Live TH-4; 5-FU + Supernatant TH-4; and 5-FU + Dead TH-4.5-FU (150 mg.kg-1) was administered by a single intraperitoneal injection on day zero; animals were killed on day four. Treatments were administered daily from days -2 to +3 via oro-gastric gavage. Metabolic parameters were measured daily. Blood was obtained by cardiac puncture, and intestinal tissues removed for quantitative and qualitative histological assessment, including: villus height and area; crypt depth and area, mitotic count and crypt fission;biochemical determination of sucrase and myeloperoxidase (MPO)activity; and disease severity scoring. One-way ANOVA statistical analyses were conducted for the majority of outcome measures. Live TH-4 significantly reduced disease severity score by 13% (p< 0.05), and partially normalized mitotic counts compared with 5-FU + Skim Milk controls. Live and Supernatant TH-4 reduced crypt fission by 69% and 48% (p < 0.05), respectively, compared to 5-FU + Skim Milk controls. No significant differences (p > 0.05) in the occurrence of bacteraemia were evident across all groups. Live TH-4 partially normalized mitotic count and histological severity score in 5-FU treated rats. The inhibitory effect of live TH-4 and TH-4 Supernatant on crypt fission suggests therapeutic utility in the prevention of disorders characterized by increased crypt fission,such as colorectal carcinoma.

Oral ingestion of streptococcus thermophilus diminishes severity of small intestinal mucositis in methotrexate treated rats.

BACKGROUND: Currently, there are no available effective preventative or adjunctive agents to alleviate symptoms of chemotherapy-induced mucositis. This is compounded by the absence of a recognized and validated noninvasive biomarker to assess gut function. This study investigated the effects of orally ingested Streptococcus thermophilus (TH-4) on chemotherapy-induced small intestinal damage in rats using the noninvasive (13)C-sucrose breath test (SBT). METHODS: Gastrointestinal damage was induced in 27 female dark agouti rats (148 +/- 1g) with MTX (1.5 mg/kg; i.m.). Rats received MTX or saline at 0 h; with daily treatment of: TH-4 at doses of 10(9) (high), 10(8) (low) cfu/mL, or skim milk (vehicle), 48 h pre and 96 h post-MTX. The noninvasive (13)C-sucrose breath test (SBT) was conducted at -24, 24 and 96 h post-MTX to monitor gut function. At sacrifice, small intestinal tissues were collected for determinations of sucrase activity, myeloperoxidase (MPO) activity and histological assessment. RESULTS: MTX + vehicle and MTX + low TH-4-treated rats produced significantly lower SBT and sucrase activity results compared to saline controls (p < 0.001). In contrast, MTX + high TH-4 treatment showed no significant differences in the SBT compared to saline controls, and the SBT results were significantly higher compared to MTX + vehicle and MTX + low TH-4 (p < 0.05). MPO levels were significantly elevated (p < 0.05) in MTX + vehicle and MTX + low TH-4, but not following MTX + high TH-4 treatment, compared to saline controls. This was further confirmed by histological analyses. CONCLUSION: Oral ingestion of TH-4 at 10(9) cfu/mL is capable of partially attenuating small bowel damage in rats. The noninvasive SBT is a useful technique to longitudinally assess the efficacy of treatments or interventions for small bowel disease.