Lactulose in combination with soybean lecithin has a cryoprotective effect on probiotic taxa of bifidobacteria and Lactobacillaceae.

Lactulose is commonly used in pharmacy for constipation and hepatic encephalopathy treatment. The prebiotic effect of lactulose is also often mentioned. However, its cryoprotective effect in combination with lecithin on the main representatives of probiotics has not been tested yet. The 12 taxa of bifidobacteria and Lactobacillaceae members were used for the purpose. These were mixed in a ratio of 1:1 with lactulose + lecithin (finally 5.0% and 1.25%, respectively; LL). The 25% glycerol (G+) solution and cultures themselves were applied as positive and negative controls, respectively. Bacterial suspensions were stored at a mild freezing temperature (-20°C) until the end of the experiment (210th day). The LL solution had a comparable (insignificant difference at the P-value = 0.05) cryoprotective effect as the positive control in five of six bifidobacteria and in three of six representatives of Lactobacillaceae. The better cryoprotective effect was revealed in other Lactobacillaceae. At the end of the experiment, the generally accepted therapeutic minimum (>107 Colony Forming Units/mL) was determined in LL solution in five bifidobacteria and four Lactobacillaceae strains. The presented results improve knowledge about long-term mild cryopreservation of the most commonly used probiotics and could contribute to developing new forms of (nutri)synbiotics.

Preterm Life in Sterile Conditions: A Study on Preterm, Germ-Free Piglets.

Preterm infants born with immature organ systems, which can impede normal development, can also be highly sensitive to different biological and/or environmental factors. Animal models could aid in investigating and understanding the effects of different conditions on the health of these immunocompromised infants. The epitheliochorial placentation of the pig prevents the prenatal transfer of protective colostral immunoglobulins. Surgical colostrum-deprived piglets are free of maternal immunoglobulins, and the cells that are normally provided via colostrum. We bred preterm germ-free piglets in sterile conditions and compared them with their term counterparts. Enterocyte development and intestinal morphology, tight junction proteins claudin-1 and occludin, pattern-recognizing receptors, adaptor molecules and coreceptors (RAGE, TLR2, TLR4, TLR9, MyD88, TRIF, MD2, and CD14), and inflammasome NLRP3 transcription were all evaluated. The production of inflammatory mediators IFN-α, IL-4, IL-6, IL-8, IL-10, IL-12/23 p40, TNF-α, IFN-γ, and high mobility group box 1 (HMGB1) in the intestine of germ-free piglets was also assessed. In the preterm germ-free piglets, the ileum showed decreased lamina propria cellularity, reduced villous height, and thinner and less distinct stratification - especially muscle layer, in comparison with their term counterparts. Claudin-1 transcription increased in the intestine of the preterm piglets. The transcription levels of pattern-recognizing receptors and adaptor molecules showed ambiguous trends between the groups. The levels of IL-6, IL-8, IL-10, and TNF-α were increased in the preterm ileum numerically (though not significantly), with statistically significant increases in the colon. Additionally, IL-12/23 p40 and IFN-γ were statistically significantly higher in the preterm colon. Both blood plasma and intestinal HMGB1 levels were nonsignificantly higher in the preterm group. We propose that the intestine of the preterm germ-free piglets showed "mild inflammation in sterile conditions." This model, which establishes preterm, hysterectomy-derived germ-free piglets, without protective maternal immunoglobulins, can be used to study influences of microbiota, nutrition, and therapeutic interventions on the development and health of vulnerable immunocompromised preterm infants.

Cross-talk of human gut with bifidobacteria.

The gut constitutes a prominent part of the immune system. Its commensal microflora plays an important role in defense and in tolerance to diet allergens. Disturbances in immune regulations may lead to food allergy. Among commensal bacteria, bifidobacteria are able to induce mechanisms of immune tolerance. Comprehension of their mutual cross-talk with the host is necessary for understanding their role in the diet and in food supplements.