Bifidobacterium Abundance in Early Infancy and Vaccine Response at 2 Years of Age.

BACKGROUND: The intestinal microbiome in early infancy affects immunologic development and thus may affect vaccine memory, though few prospective studies have examined such associations. We examined the association of Bifidobacterium levels in early infancy with memory responses to early vaccination measured at 2 years of age. METHODS: In this prospective observational study, we examined the association of Bifidobacterium abundance in the stool of healthy infants at 6 to 15 weeks of age, near the time of vaccination, with T-cell and antibody responses measured at 6 weeks, 15 weeks, and 2 years of age. Infants were vaccinated with Bacillus Calmette-Guérin (BCG) (at birth), oral polio virus (at birth and at 6, 10, and 14 weeks), tetanus toxoid (TT) (at 6, 10, and 14 weeks), and hepatitis B virus (at 6, 10, and 14 weeks). Fecal Bifidobacterium was measured at 6, 11, and 15 weeks. Bifidobacterium species and subspecies were measured at 6 weeks. RESULTS: Mean Bifidobacterium abundance in early infancy was positively associated with the CD4 T-cell responses to BCG, TT, and hepatitis B virus at 15 weeks, with CD4 responses to BCG and TT at 2 years, and with plasma TT-specific immunoglobulin G and stool polio-specific immunoglobulin A at 2 years. Similar associations were seen for the predominant subspecies, Bifidobacterium longum subspecies infantis. CONCLUSIONS: Bifidobacterium abundance in early infancy may increase protective efficacy of vaccines by enhancing immunologic memory. This hypothesis could be tested in clinical trials of interventions to optimize Bifidobacterium abundance in appropriate populations.

Microbial screening of unrelated cord blood units in a Chinese cord blood bank.

BACKGROUND: Given limited sample volume available for sterility testing, optimal testing methods and algorithms of cord blood (CB) have not been established according to standards. STUDY DESIGN AND METHODS: The volume of CB unit was reduced to 20 mL in a closed system. Hetastarch and cryopreservation solution was added to the processed CB unit in Class 100 environment. In the routine sterility testing, 20 mL of red blood cells (RBC) sample was cultured in aerobic and anaerobic culture bottles. In verification post-thaw culture of the final product, some of the discarded final product units were also sampled and cultured after thaw. All the culture bottles were incubated in the BacT/ALERT 3D system. RESULTS: In the routine sterility testing, 139 of 7032 CB units (1·98%) were contaminated with microorganism. In 84 of these 139 units (60·4%) only the anaerobic bottle was positive. Lactobacillus spp. were the most prevalent contaminant. Sixty-two discarded CB stem cell units were recultured after thaw. Of these, 10 of 48 units with a positive culturing of RBC sample were negative in the post-thaw reculture. One of 14 units with negative culturing of RBC sample was contaminated with Bifidobacterium breve in special verification test. CONCLUSION: Our study demonstrates the predominant organisms implicated in CB microbial contamination were part of the human intestinal and vaginal flora. The larger sample volume and anaerobic culture would significantly increase the detection rate of microbial contaminated CB. We also found that potential transfusion-transmitted bacterial infection risk still existed in final product although microbial screening was performed.

Bifidobacterium lactis inhibits NF-kappaB in intestinal epithelial cells and prevents acute colitis and colitis-associated colon cancer in mice.

BACKGROUND: The aim of this study was to investigate the antiinflammatory effects of Bifidobacterium lactis on intestinal epithelial cells (IECs) and on experimental acute murine colitis and its tumor prevention effects on colitis-associated cancer (CAC) in mice. METHODS: Human HT-29 cells were stimulated with IL-1beta, lipopolysaccharides, or tumor necrosis factor-alpha with and without B. lactis, and the effects of B. lactis on nuclear factor kappa B (NF-kappaB) signaling in IEC were examined. For in vivo study, dextran sulfate sodium (DSS)-treated mice were fed with and without B. lactis. Finally, we induced colonic tumors in mice by azoxymethane (AOM) and DSS and evaluated the effects of B. lactis on tumor growth. RESULTS: B. lactis significantly suppressed NF-kappaB activation, including NF-kappaB-binding activity and NF-kappaB-dependent reporter gene expression in a dose-dependent manner, and suppressed IkappaB-alpha degradation, which correlated with the downregulation of NF-kappaB-dependent gene products. Moreover, B. lactis suppressed the development of acute colitis in mice. Compared with the DSS group, the severity of DSS-induced colitis as assessed by disease activity index, colon length, and histological score was reduced in the B. lactis-treated group. In the CAC model, the mean number and size of tumors in the B. lactis-treated group were significantly lower than those in the AOM group. CONCLUSIONS: Our data demonstrate that B. lactis inhibits NF-kappaB and NF-kappaB-regulated genes in IEC and prevents acute colitis and CAC in mice. These results suggest that B. lactis could be a potential preventive agent for CAC as well as a therapeutic agent for inflammatory bowel disease.