Rotavirus Double Infection Model to Study Preventive Dietary Interventions.

Rotaviruses are the main cause of acute diarrhea among young children worldwide with an increased frequency of reinfection. Several life style factors, such as dietary components, may influence such processes by affecting the outcome of the first rotavirus infection and therefore having a beneficial impact on the anti-rotavirus immune responses during any subsequent reinfections. The aim of this research was to develop a double-infection model in rat that mimics real-life clinical scenarios and would be useful in testing whether nutritional compounds can modulate the rotavirus-associated disease and immune response. Three experimental designs and a preventive dietary-like intervention were conducted in order to achieve a differential response in the double-infected animals compared to the single-infected ones and to study the potential action of a modulatory agent in early life. Diarrhea was only observed after the first infection, with a reduction of fecal pH and fever. After the second infection an increase in body temperature was also found. The immune response against the second infection was regulated by the preventive effect of the dietary-like intervention during the first infection in terms of specific antibodies and DTH. A rotavirus-double-infection rat model has been developed and is suitable for use in future preventive dietary intervention studies.

The incidence of infants with rotavirus enteritis combined with lactose intolerance.

UNLABELLED: This study was to research the incidence of infants with rotavirus enteritis combined with lactose intolerance and the clinical effect of low lactose milk powder for infantile rotavirus enteritis with lactose intolerance. The control groups were 126 cases of infants with diarrhea randomly collected from our hospital at the same period, which their rotavirus detection was negative. The observation group was 185 cases of infants with rotavirus, which was tested to be positive. Through the urine galactose determination, 62 cases of the control group were positive and 124 cases of the observation group were positive. Then 124 cases of infants with rotavirus combined with lactose intolerance were randomly divided into two groups. 60 cases in the control group were given rehydration, correction of acidosis, oral smecta, Intestinal probiotics and other conventional treatment, then continued to the original feeding method. While, 64 cases in the treatment group, on the basis of routine treatment, applied the low lactose milk feeding. To observe the total effective rate for the two groups. The incidence of lactose intolerance in children with rotavirus enteritis (67.03%) was significantly higher than that of children with diarrhea (49.2%), which was tested to be negative. And the difference was statistically significant (p<0.5). In the aspect of reducing the frequency of diarrhea, and diarrhea stool forming time, the treatment group has the obvious superiority. The total effective rate was 95.4% for treatment group, which was higher than that in the control group (76.7%), the difference was statistically significant (P<0.05). CONCLUSION: Infants with rotavirus enteritis was easier to merge with lactose intolerance. The low lactose milk powder could improve the therapeutic effectively and could reduce the duration of disease, and restored to normal diet for 2 weeks feeding time.

Probiotic bacteria, B. longum and L. acidophilus inhibit infection by rotavirus in vitro and decrease the duration of diarrhea in pediatric patients.

BACKGROUND AND OBJECTIVES: Evidence suggests that specific probiotics may be antagonistic to enteric pathogens and enhance immunity, and thus, provide a means of preventing or treating diarrheal diseases. In the present study, we aimed to evaluate the efficacy of probiotic strains isolated from Koreans for the treatment of viral gastroenteritis in young children and against rotavirus in vitro. METHODS: In vitro antiviral activities of probiotic isolates on rotavirus infection were investigated in the Vero cell using a plaque reduction assay. Then several probiotic strains with the high antiviral activity were chosen for further clinical trials. Twenty-nine pediatric patients who presented with symptoms of viral gastroenteritis were enrolled in a double-blind trial and randomly assigned at admission to receive six probiotic strains (Bifidobacterium longum, B. lactis, Lactobacillus acidophilus, L. rhamnosus, L. plantarum, and Pediococcus pentosaceus) at a dose of 10(9) colony forming units/g or a comparable placebo twice daily for 1 week. RESULTS AND CONCLUSIONS: Of the tested probiotic strains, B. longum isolated from an infant showed the greatest inhibitory effect and L. acidophilus showed the second-highest inhibitory effect. These probiotics significantly shortened the duration of diarrhea as compared with a placebo (6.1 ± 0.5 vs 7.2 ± 1.9, P = 0.030) and did not induce any adverse effects. Our findings suggest that the probiotic strains selected in the present study may be useful for the treatment of acute rotaviral gastroenteritis or as an alternative therapy without adverse effects.

Supplementing suckling rats with whey protein concentrate modulates the immune response and ameliorates rat rotavirus-induced diarrhea.

Group A rotaviruses (RV) are the most common causative agents of acute gastroenteritis in children <2 y. The present study was designed to establish the effect of a bovine whey protein concentrate (WPC) in a RV infection model in suckling rats. From d 3 of life, suckling Lewis rats received daily supplements of WPC, WPC plus lactoferrin (LF), standard infant formula (SIF), or water (RV-infected group and an untreated, uninfected reference group). On d 8 of life, heterologous simian RV SA-11 was inoculated orally in the WPC-RV, WPC+LF-RV, SIF-RV, and RV groups. WPC and WPC+LF reduced diarrhea incidence from approximately 90% in RV group to approximately 60% in WPC-RV and WPC+LF-RV groups (P < 0.05), whereas the area under the curve (AUC) of severity along time diminished from approximately 10 AUC in the RV group to approximately 6 AUC in both supplemented groups (P < 0.05). Serum levels of anti-RV antibodies, splenocyte proliferation, and interferon-gamma secretion after specific stimulation were significantly lower in the WPC-RV and WPC+LF-RV groups than in the SIF-RV and RV groups. In the intraepithelial intestinal compartment, RV infection increased the proportion of typical mucosal T cells (IE-T CD8alphaalpha+); however, this modification was controlled by WPC and WPC+LF supplementation. In general, for most of the parameters studied, the SIF-RV and RV groups did not differ. In summary, daily supplementation with WPC or WPC+LF in early life considerably reduces the severity of RV-induced acute gastroenteritis and modulates the immune response against the pathogen.

Contribución de la microbiota intestinal y del género "Bifidobacterium" a los mecanismos de defensa del huésped frente a patógenos gastrointestinales / Contribution of the intestinal microbiota and the genus Bifidobacterium to the host defense mechanisms against gastrointestinal pathogens

La microbiota intestinal constituye un complejo ecosistema que desempeña una importante función en el estado de salud del ser humano. Como consecuencia de ello, se ha producido una rápida incorporación de cepas bacterianas con funciones beneficiosas definidas (probióticos) al mercado. El efecto protector de las bacterias probióticas frente a patógenos gastrointestinales y sus mecanismos de acción ha sido una de las áreas que ha despertado mayor interés. Las cepas del género Bifidobacterium son integrantes mayoritarios de la microbiota intestinal de los niños y uno de los principales grupos de probióticos. Este género se considera esencial para el mantenimiento del equilibrio intestinal. Ciertas bifidobacterias son capaces de ejercer in vitro efectos antagónicos frente a importantes patógenos gastrointestinales pertenecientes a los géneros Listeria, Clostridium, Salmonella, Shigella, Proteus, Escherichia y Candida. Datos clínicos también permiten atribuir una función protectora a ciertas bifidobacterias probióticas frente a las diarreas infecciosas agudas y la diarrea asociada a antibióticos en niños. Existe un número cada vez mayor de estudios que indican que algunas bifidobacterias pueden contribuir a fortalecer las defensas todavía inmaduras en edades tempranas de la vida mediante diversos mecanismos (exclusión competitiva, inmunomodulación, síntesis de compuestos antimicrobainos, etc.). No obstante, será necesario realizar un mayor número de ensayos clínicos rigurosos con cepas probióticas bien definidas para poder establecer recomendaciones consensuada sobre el consumo de productos probióticos con fines específicos para la población infantil

The human intestinal microbiota constitutes a complex ecosystem that plays an important role in human health. This has led to a rapid incorporation of bacterial strains that exhibited specific beneficial properties( probiotics)in to the market. The protective role of probiotic bacteria against gastrointestinal pathogens and the underlying mechanisms has received special attention. Bifidobacteriums trains are predominant in habitants of the intestinal tract of infants and one of the main sources of probiotic strains. This genus is considered to be essential for maintaining the balance of the intestinale cosystem. Bifidobacterium strains exert in vitro antagonistic activity against important gastrointestinal pathogens belonging to the genera Listeria, Clostridium, Salmonella, Shigella, Proteus, Escherichia and Candida. Clinical evidences also support a protective role of some probiotic bifidobacteria in acute infectious diarrhea and antibiotic-associated diarrhea in children. There is an increasing body of evidence about the multiple mechanisms (competitive exclusion, immunomodulation, synthesis of antimicrobials, etc.) by which bifidobacteria could promote the immature infant defenses. More over, a large number of rigorous clinical trials on well-identified probiotics trains will be required to find general recommendations of probiotic-containing products for specific purposes in the infant population

Use of soy fiber in acute diarrhea in infants and toddlers.

Soy fiber has been shown to reduce the duration of watery stools during acute diarrhea caused by bacterial and viral pathogens in underdeveloped countries. A randomized blinded clinical trial was conducted with middle-class American children to assess the efficacy of soy fiber-supplemented infant formula. Stool characteristics, intake, and weight were recorded. Infants > 6 months of age (n = 44) fed soy fiber-supplemented formula (Isomil DF) had a significantly shorter estimated median duration of diarrhea (9.7 hours vs. 23.1 hours) than those fed soy formula (Isomil). The use of fiber-supplemented soy formula may reduce the duration of diarrheal symptoms in U.S. infants more than 6 months of age with acute diarrhea.

Diet during rotavirus enteritis affects jejunal permeability to macromolecules in suckling rats.

We studied the influence of diet during diarrhea on gut mucosal barrier in a suckling rat model. Rat pups were inoculated with IDIR virus (a group B rotavirus) at 10 d of age. Beginning 2 d postinfection, in addition to maternal milk, group CM received a daily gavage of cow milk and group GG received Lactobacillus casei strain GG, a human strain previously shown to survive the passage through the gastrointestinal tract and temporarily colonize the gut. Group CMGG received a combination of these, and control animals were gavaged with tap water. At 21 d of age, jejunal absorption of intact and degraded horseradish peroxidase (HRP) in Ussing chamber was markedly higher in IDIR virus-infected than in noninfected controls. In the two groups gavaged with cow milk, group CM and group CMGG, the numbers of specific antibody-secreting cells (enumerated by the solid-phase enzyme-linked immunospot assay) against beta-lactoglobulin were significantly higher than in the groups that had not received cow milk. In parallel with immune system activation, a statistically significant increase in the absorption of intact HRP (mean and 95% confidence interval, ng x h-1 x cm-2) was detected: group CM, 302 (155, 586); group CMGG, 174 (56, 545); infected controls, 121 (57, 257); and group GG, 44 (8, 254). A decrease in the uptake of intact HRP (F = 3.64, p = 0.06) and degraded HRP (F = 9.50, p = 0.004) was associated with the introduction of L. casei GG to the diet, irrespective of coexposure to cow milk.(ABSTRACT TRUNCATED AT 250 WORDS)

Cow's milk-based formula, human milk, and soya feeds in acute infantile diarrhea: a therapeutic trial.

Acute infantile diarrhea is often managed by introducing lactose-free diets empirically from the time of diagnosis, in addition to conventional rehydration therapy. In order to assess the efficacy of this, a therapeutic trial was undertaken in which hospitalized gastroenteritis patients previously on milk-formula feeds were randomly fed, from the time of admission, either their original feed or a lactose-free soya preparation; patients previously on human milk with or without a supplement continued to receive this during their diarrheal illness. The results show that in nonrotaviral gastroenteritis, there is no difference in the duration of the illness irrespective of the type of feed given. In rotaviral gastroenteritis, continued breast-feeding significantly reduces the duration of acute diarrhea, while lactose-free soya feeds do not lead to a significant reduction in the duration of the illness when compared to cow's milk-formula feeds. Hence, it is concluded that (a) breast-feeding should be continued during an episode of infantile diarrhea, and that (b) empirical use of soya preparations from the time of hospital admission is not justified; however, the latter should be considered in infants whose purging rate goes up or diarrheal disease severity worsens 3 to 4 days after the onset of diarrhea or hospital stay and who are passing significant amounts of reducing sugars in their stool.

PIP: Acute infantile diarrhea is often managed by introducing lactose-free diets empirically from the time of diagnosis, in addition to conventional rehydration therapy. In order to assess the efficacy of this, a therapeutic trial was undertaken in which hospitalized gastroenteritis patients previously on milk-formula feeds were randomly fed, from the time of admission, either their original feed or a lactose-free soya preparation. Patients who had previously had human milk with or without a supplement continued to receive this during their diarrheal illness. The results show that in nonrotaviral gastroenteritis, there is no difference in the duration of the illness, irrespective of the type of feed given. In rotaviral gastroenteritis, continued breastfeeding significantly reduces the duration of acute diarrhea, while lactose-free soya feeds do not lead to a significant reduction in the duration of the illness when compared to cow's milk- formula feeds. Therefore, the authors concluded that: breastfeeding should be continued during an episode of infantile diarrhea, and empirical use of soya preparations from the time of hospital admission is not justified. However, the latter should be considered in infants whose purging rate goes up or diarrheal disease severity worsens 3-4 days after diarrhea onset or hospital stay and who are passing significant amounts of reducing sugars in their stool.

Effects of environmental and dietary factors on human rotavirus infection in gnotobiotic piglets.

The addition of proteolytic enzyme to diets fed to newborn gnotobiotic piglets exacerbated their diarrheal response after oral infection with human rotaviruses. Supplementation of diets with proteolytic enzyme and reduced ambient temperature were evaluated for effects upon the clinical response of gnotobiotic piglets infected with human rotavirus Wa strain, type 2. Piglets were divided into four treatment groups combining two variables: ambient temperature of 35 or 26 degrees C, with and without proteolytic enzyme supplementation of the diet. Infected piglets maintained at 26 degrees C with and without enzyme supplementation had 90 and 70% mortality, respectively. No mortality was observed in infected piglets maintained at 35 degrees C. Protease supplementation of diets fed to piglets kept at 35 degrees C resulted in more uniform onset of diarrhea of greater severity than in littermates fed diets without the supplementation.

Effect of dietary regimen on rotavirus-Escherichia coli weanling diarrhea of piglets.

Previously, we induced weanling diarrhea in piglets by infecting them with rotavirus followed by hemolytic enteropathogenic Escherichia coli. We postulated that rotavirus, by damaging the epithelium of the small intestines, produced an enteroenvironment which favored the selection and growth of enteropathogenic E. coli. Furthermore, diet might affect the enteroenvironment and influence the course of the disease. To test this, newly weaned 3-week-old piglets were assigned to one of four dietary regimens and infected with rotavirus followed 24 h later with enteropathogenic E. coli. The course of the disease was followed by monitoring the severity of diarrhea and the fecal shedding of rotavirus and enteropathogenic E. coli in these dually infected piglets. The dietary regimen designed to tax the digestive and absorptive capacities of the piglets (high nutrient intake fed three times a day) produced the most prolonged diarrhea, colonization of the gut by hemolytic enteropathogenic E. coli, and persistent shedding of rotavirus (P less than 0.01). The same nutrient intake divided into 24 equal increments and fed hourly produced a less severe response (P less than 0.01). The least severe response was seen in piglets fed one-third the nutrient intake either hourly or three times a day (P less than 0.01). We conclude that dietary regimen plays an important role in rotavirus-E. coli-induced weanling diarrhea.