Synbiotic Effect of Bifidobacterium lactis CNCM I-3446 and Bovine Milk-Derived Oligosaccharides on Infant Gut Microbiota

BACKGROUND

This study evaluated the impact of Bifidobacterium animalis ssp. lactis CNCM I-3446, Bovine Milk-derived OligoSaccharides (BMOS) and their combination on infant gut microbiota in vitro. In addition, a novel strategy consisting of preculturing B. lactis with BMOS to further enhance their potential synbiotic effects was assessed.

METHOD

Short-term fecal batch fermentations (48 h) were used to assess the microbial composition and activity modulated by BMOS alone, B. lactis grown on BMOS or dextrose alone, or their combinations on different three-month-old infant microbiota.

RESULTS

BMOS alone significantly induced acetate and lactate production (leading to pH decrease) and stimulated bifidobacterial growth in 10 donors. A further in-depth study on two different donors proved B. lactis ability to colonize the infant microbiota, regardless of the competitiveness of the environment. BMOS further enhanced this engraftment, suggesting a strong synbiotic effect. This was also observed at the microbiota activity level, especially in a donor containing low initial levels of bifidobacteria. In this donor, preculturing B. lactis with BMOS strengthened further the early modulation of microbiota activity observed after 6 h.

CONCLUSION

This study demonstrated the strong synbiotic effect of BMOS and B. lactis on the infant gut microbiota, and suggests a strategy to improve its effectiveness in an otherwise low-Bifidobacterium microbiota.

Effect of Bifidobacterium animalis subsp. lactis GCL2505 on the physiological function of intestine in a rat model

Bifidobacterium animalis ssp. lactis GCL2505 has been shown to proliferate in the human intestine. The intestinal dynamics and physiological effects of GCL2505 as well as the mechanism underlying proliferation in the gut were investigated. GCL2505 showed markedly higher resistance to free bile acids (cholic and deoxycholic acids) than other bifidobacterial species. The intestinal dynamics of GCL2505 and B. longum ssp. longum JCM1217^T was compared. The level of B. animalis ssp. lactis in the GCL2505‐administered group was remarkably higher than that of B. longum in the JCM1217^T‐administered group. The distribution of B. animalis ssp. lactis through the intestine of the GCL2505‐administered group revealed that GCL2505 proliferated in the cecum. The physiological effects of GCL2505 and JCM 1217^T were investigated. The cecal IgA level in the GCL2505‐administered group was significantly higher than that in the nontreated control group. In contrast, the JCM 1217^T‐administered group did not manifest any change in the cecal IgA level. Mucin excretion in the GCL2505‐administered group was significantly higher than that in the JCM 1217^T‐administered group. The thickness of the sulfomucin layer of the colon in the GCL2505‐administered group tended to be higher than that in the JCM 1217^T‐administered group. In a loperamide‐induced constipation model, fecal excretion in the GCL2505‐administered group was significantly increased compared with that in the loperamide‐treated control group. Short‐chain fatty acid concentration in the GCL2505‐administered group was significantly higher than that in the loperamide‐treated control group. These results indicate that the level of proliferation of probiotics in the intestine correlates with the magnitude of host physiological responses, such as IgA production and mucin secretion, which possibly affect gastrointestinal functions such as bowel movement to counteract constipation. GCL2505 exhibits high tolerance to secondary bile acids, which partially explains its higher rate of proliferation in the large intestine.