A Galactooligosaccharide Product Decreases the Rotavirus Infection in Suckling Rats.

The leading cause of gastroenteritis among young children worldwide is the Group A rotaviruses (RV), which produce a wide range of symptoms, from a limited diarrhea to severe dehydration and even death. After an RV infection, immunity is not complete and less severe re-infections usually occur. These infections could be ameliorated by nutritional interventions with bioactive compounds, such as prebiotics. The aim of this research was to study the impact of a particular galactooligosaccharide (B-GOS) on the RV symptomatology and immune response during two consecutive infections. Lewis neonatal rats were inoculated with SA11 (first RV infection) on day 6 of life and with EDIM (second RV infection) on day 17 of life. B-GOS group was administered by oral gavage with a daily dose of B-GOS between days three to nine of life. Clinical and immunological variables were assessed during both infective processes. In the first infection, after the prebiotic intervention with B-GOS, a lower incidence, duration, and overall severity of the diarrhea (p < 0.05) was observed. In addition, it improved another severity indicator, the fecal weight output, during the diarrhea period (p < 0.05). The second RV infection failed in provoking diarrhea in the groups studied. The immune response during first infection with SA11 was not affected by B-GOS administration and had no impact on second infection, but the prebiotic intervention significantly increased IFN-γ and TNF-α intestinal production after the second infection (p < 0.05). In summary, B-GOS supplementation is able to reduce the incidence and severity of the RV-associated diarrhea and to influence the immune response against RV infections.

Prevention of Rotavirus Diarrhea in Suckling Rats by a Specific Fermented Milk Concentrate with Prebiotic Mixture.

Several microbial modulatory concepts, such as certain probiotics and prebiotics, confer protection against gastrointestinal infections, among which is acute diarrhea caused by the rotavirus (RV). Other microbiota modulators, such as postbiotics, produced during fermentation, might also have the potential to counteract RV infection. In light of this, a fermented milk, made by using Bifidobacterium breve C50 (BbC50) and Streptococcus thermophilus 065 (St065) with a prebiotic mixture-short chain galactooligosaccharides/long chain fructooligosaccharides (scGOS/lcFOS 9:1)-with potential to impact the intestinal microbiota composition was tested. An RV infected rat model was used to evaluate the amelioration of the infectious process and the improvement of the immune response induced by the fermented milk with prebiotic mixture. The dietary intervention caused a reduction in the clinical symptoms of diarrhea, such as severity and incidence. Furthermore, a modulation of the immune response was observed, which might enhance the reduction of the associated diarrhea. In addition, the fermented milk with prebiotic mixture was able to bind the virus and reduce its clearance. In conclusion, the postbiotic components in the fermented milk in combination with the prebiotics used here showed protective properties against RV infection.

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.

Preventive Effect of a Synbiotic Combination of Galacto- and Fructooligosaccharides Mixture With Bifidobacterium breve M-16V in a Model of Multiple Rotavirus Infections.

Rotavirus (RV) causes morbidity and mortality among infants worldwide, and there is evidence that probiotics and prebiotics can have a positive influence against infective processes such as that due to RV. The aim of this study was to evidence a preventive role of one prebiotic mixture (of short-chain galactooligosaccharide/long-chain fructooligosaccharide), the probiotic Bifidobacterium breve M-16V and the combination of the prebiotic and the probiotic, as a synbiotic, in a suckling rat double-RV infection model. Hyperimmune bovine colostrum was used as protection control. The first infection was induced with RV SA11 and the second one with EDIM. Clinical variables and immune response were evaluated after both infections. Dietary interventions ameliorated clinical symptoms after the first infection. The prebiotic and the synbiotic significantly reduced viral shedding after the first infection, but all the interventions showed higher viral load than in the RV group after the second infection. All interventions modulated ex vivo antibody and cytokine production, gut wash cytokine levels and small intestine gene expression after both infections. In conclusion, a daily supplement of the products tested in this preclinical model is highly effective in preventing RV-induced diarrhea but allowing the boost of the early immune response for a future immune response against reinfection, suggesting that these components may be potential agents for modulating RV infection in infants.

Preclinical Immunomodulation by the Probiotic Bifidobacterium breve M-16V in Early Life.

This study aimed to investigate the effect of supplementation with the probiotic Bifidobacterium breve M-16V on the maturation of the intestinal and circulating immune system during suckling. In order to achieve this purpose, neonatal Lewis rats were supplemented with the probiotic strain from the 6th to the 18th day of life. The animals were weighed during the study, and faecal samples were obtained and evaluated daily. On day 19, rats were euthanized and intestinal wash samples, mesenteric lymph node (MLN) cells, splenocytes and intraepithelial lymphocytes (IEL) were obtained. The probiotic supplementation in early life did not modify the growth curve and did not enhance the systemic immune maturation. However, it increased the proportion of cells bearing TLR4 in the MLN and IEL, and enhanced the percentage of the integrin αEß7+ and CD62L+ cells in the MLN and that of the integrin αEß7+ cells in the IEL, suggesting an enhancement of the homing process of naïve T lymphocytes to the MLN, and the retention of activated lymphocytes in the intraepithelial compartment. Interestingly, B. breve M-16V enhanced the intestinal IgA synthesis. In conclusion, supplementation with the probiotic strain B. breve M-16V during suckling improves the development of mucosal immunity in early life.