Daily ReCAP April 3, 2017

Chronic: Early-Life Antibiotic Use Associated With Development of Irritable Bowel Disease

The use of antibiotics early in life alters the normal development and growth of gut bacteria, which may contribute to the development of inflammatory bowel disease (IBD). The findings further support the idea that altering gut flora may be a viable treatment strategy for some inflammatory diseases. In a study published in theJournal of Leukocyte Biology, investigators used 2 groups of mice. The first included pregnant females treated with broad-spectrum antibiotics during pregnancy and pups treated with broad-spectrum antibiotics for the first 3 weeks of life. The second group was a control group comprising untreated mothers and pups. In the treated arm, the pups were weaned at 3 weeks of age, and antibiotic treatment was stopped at the same time. The pups had reduced levels of gut bacteria and could age normally. At 8 weeks of age, CD4 T cells from both the treated and untreated pups were examined for their ability to induce IBD in other mice, according to the study. The immune cells from antibiotic-treated mice induced a more rapid and severe disease compared with those from the untreated mice. “Our study demonstrates that gut bacteria in early life do affect disease development in adulthood, but this response can be changed,” said investigators Colby Zaph, head of the Laboratory of Mucosal Immunity and Inflammation, School of Biomedical Sciences at Monash University, Australia. “This has important ramifications for the use of pre- and probiotics, the administration of antibiotics to neonates, and our understanding of how gut bacteria play a critical role in influencing the development of inflammatory diseases such as IBD.”

Acute: Higher Doses of Vitamin C May Reduce Common Cold Duration

Increasing the dosage of vitamin C to 6 g or 8 g per day may reduce the duration of the common cold, according to investigators. Most controlled trials examining the impact of vitamin C have used a dosage of 1 g per day of vitamin C. Although the combined effect of all the published studies has shown a statistically highly significant difference between the vitamin C and placebo groups, the optimal doses and maximal effects of vitamin C on the common cold are unknown. In a new a study, investigators analyzed findings of 2 randomized trials that examined the effects of 2 vitamin C doses on the duration of the common cold. In the first trial, 3 g per day of vitamin C were administered to 2 study groups, 6 g per day to a third group, and a placebo was administered to the fourth group. The results of the study showed that, compared with the placebo group, the group taking a dose of 6 g per day experienced shortened colds by 17%, which was twice as much as the group taking 3 g per day doses. The second trial administered 4 g per day of vitamin C, 8 g per day, and a placebo to different groups but only on the first day of the cold. Compared with the placebo, the 8 g per day dose shortened colds by 19%, twice as much as the 4 g per day dose. Both studies showed a significant dose—response relationship between the vitamin C dosage and the duration of the common cold. Furthermore, the dose response relationship in the 2 trials were linear up to the levels of 6 g to 8 g per day, meaning that even higher doses may lead to greater reductions in the duration of common cold. Although there have been proposals that vitamin C doses should be greater than 15 g per day for the best treatment of colds, the highest doses that have been investigated in randomized trials thus far have been significantly lower. “Given the consistent effect of vitamin C on the duration of colds, and its safety and low cost, it would be worthwhile for individual common cold patients to test whether therapeutic 8 g/day vitamin C is beneficial for them,” said investigator Dr Harri Hemilä. “Self-dosing of vitamin C must be started as soon as possible after the onset of common cold symptoms to be most effective."

Preventive: Flu Vaccinations Reduce the Risk of Death Among Children, CDC Study Finds

Influenza vaccinations were associated with the reduced risk of influenza-associated pediatric death, according to a new CDC study published inPediatric. Since 2004, surveillance for laboratory-confirmed influenza-associated pediatric deaths have shown that most deaths occurred in unvaccinated children. For the case-cohort analysis, investigators sought to determine whether influenza vaccinations reduced the risk of influenza-associated death in children and adolescents. The investigators compared vaccination uptake among lab-confirmed influenza associated pediatric deaths with estimated vaccination coverage among pediatric cohorts in the United States. The results of the study showed that from July 2010 to June 2014, there were 358 lab-confirmed influenza-associated pediatric deaths reported among children aged 6 months to 17 years. Vaccination status was determined for 291 deaths, of whom 75 received vaccines before illness onset. The average vaccination coverage in survey cohorts was 48%. Overall, vaccine effectiveness against death was 65%. According to the study, among the 153 deaths in children with underlying high-risk medical conditions, 47 were vaccinated. Vaccine effectiveness among children with high-risk conditions was 51% compared with 65% among children without high-risk conditions. “Results of this study suggest that vaccination reduced the risk of influenza-associated death among children and adolescents and add to the evidence of benefits of influenza vaccination for children,” the authors concluded. “Annual vaccination is an important strategy to prevent influenza and influenza-associated complications and death. These results support current recommendations for annual influenza vaccination for all children ³6 months of age.”