Elderly people are particularly vulnerable to COVID-19, with a high risk of developing severe disease and a reduced immune response to the COVID-19 vaccine. A randomized, placebo-controlled, double-blind trial to assess the effect of the consumption of the probiotic Loigolactobacillus coryniformis K8 CECT 5711 on the immune response generated by the COVID-19 vaccine in an elderly population was performed. Two hundred nursing home residents >60 yrs that had not COVID-19 were randomized to receive L. coryniformis K8 or a placebo daily for 3 months. All volunteers received a complete vaccination schedule of a mRNA vaccine, starting the intervention ten days after the first dose. Specific IgG and IgA antibody levels were analyzed 56 days after the end of the immunization process. No differences between the groups were observed in the antibody levels. During the intervention, 19 subjects had COVID-19 (11 receiving K8 vs. 8 receiving placebo, p = 0.457). Subgroup analysis in these patients showed that levels of IgG were significantly higher in those receiving K8 compared to placebo (p = 0.038). Among subjects >85 yrs that did not get COVID-19, administration of K8 tended to increase the IgA levels (p = 0.082). The administration of K8 may enhance the specific immune response against COVID-19 and may improve the COVID-19 vaccine-specific responses in elderly populations.

The study of different natural products can provide a wealth of bioactive compounds, and more interestingly, their combination can exert a new strategy for several neurodegenerative diseases with major public health importance, such as Alzheimer’s disease (AD). Here, we investigated the synergistic neuroprotective effects of a mixed extract composed of docosahexaenoic acid, Ginkgo biloba, D-pinitol, and ursolic acid in several transgenic Caenorhabditis elegans (C. elegans) and a senescence-accelerated prone mice 8 (SAMP8) model. First, we found a significantly higher survival percentage in the C. elegans group treated with the natural product mixture compared to the single extract-treated groups. Likewise, we found a significantly increased lifespan in group of C. elegans treated with the natural product mixture compared to the other groups, suggesting synergistic effects. Remarkably, we determined a significant reduction in Aβ plaque accumulation in the group of C. elegans treated with the natural product mixture compared to the other groups, confirming synergy. Finally, we demonstrated better cognitive performance in the group treated with the natural product mixture in both AD models (neuronal Aβ C. elegans strain CL2355 and the SAMP8 mice model), confirming the molecular results and unraveling the synergist effects of this combination. Therefore, our results proved the potential of this new natural product mixture for AD therapeutic strategies.

The breast milk microbiota has been described as a source of bacteria for infant gut colonisation. We studied the effect of Lactobacillus fermentum CECT5716 (Lc40) on growth and infection incidence of the infants, when the probiotic is administrated to the mothers. Moreover, whether such effects might depend on the interaction between the mother or infant microbiota and the probiotic administration. A total of 291 mother-infant pairs were studied for 16 weeks in a randomised double-blinded placebo-controlled multicentre trial. The Lc40 group (n=139) received 1 capsule/day containing 3×10⁹ cfu Lc40; the control group (n=152) received 1 placebo (maltodextrin) capsule/day. A positive and significant correlation of the Staphylococcus load between breast milk and infant faeces was only observed in control group. Additionally, the weight z-score of the infants whose mothers had higher values of Lactobacillus in their breast milk were significantly higher for the Lc40 group. We observed a significant lower incidence of conjunctivitis in the infants whose mothers received Lc40. A higher load of Staphylococcus in infant faeces significantly increased the risk of respiratory infections. Such incidence, under an absent or low Staphylococcus load in the faeces, was significantly 36 times higher in the infants in the control group than in the infants in the Lc40 group. However, the protective effect of Lc40 was gradually reduced as the Staphylococcus load of the milk increased. The administration of Lc40 to nursing women might influence infant growth and health but it seems to depend on its interactions with mother or infant microbiota. Registered in the US Library of Medicine (www.clinicaltrials.gov): NCT02203877.

The probiotic properties of Bifidobacterium breve CECT7263, as well as its safety, have been the focus of in several studies since 2008, including the sequencing of its genome in 2012. This study aims to complete the available genomic data to deepen the knowledge of some phenotypic characteristics of this strain.