Bacterial strains of the Lactobacillaceae family are widely used as probiotics for their multifaceted potential beneficial properties. However, no official recommendations for their clinical use exist since, in many cases, oral administrations of these bacteria displayed limited beneficial effects in human. Additional research is thus needed to improve the efficiency of existing strains with strong potential. In this context, we assess in vitro the effects of nine polyphenols to stimulate biofilm formation by lactobacilli, a feature enhancing their functionalities. Among these polyphenols, we identify trans-Resveratrol (referred to hereafter as Resveratrol) as a potent inducer of biofilm formation by Lacticaseibacillus paracasei (formerly designated as Lactobacillus paracasei) ATCC334 strain. This effect is strain-dependent and relies on the enhancement of L. paracasei adhesion to abiotic and biotic surfaces, including intestinal epithelial cells. Mechanistically, Resveratrol modify physico-chemical properties of the bacterial surface and thereby enhances L. paracasei aggregation, subsequently facilitating adhesion and biofilm development. Together, our in vitro data demonstrate that Resveratrol might be used to modulate the behavior of Lactobacilli with probiotic properties. Combination of probiotics and polyphenols could be considered to enhance the probiotic functionalities in further in vivo studies.

Introduction: Toxoplasmosis is of dual importance in both public and veterinary health due to the respective risk of transplacental transmission in primo-infected pregnant women and economic losses caused by abortions in mammals. One of the main routes of Toxoplasma gondii transmission to humans is the consumption of raw or undercooked meats containing parasitic cysts. Here, we performed the first epidemiological study to determine the seroprevalence and the risk factors of toxoplasmosis in livestock in Lebanon. Methodology: Using a modified agglutination test with a cut-off of 1:40, we tested the positivity rate of Immunoglobulin G antibodies in the sera of 100 sheep and 80 goats collected from 18 different livestock farms located in North Lebanon between March and June 2018. Results: Anti-Toxoplasma gondii IgG antibodies were detected in 42% of sheep and 34% of goats. Adults (> 1 year) were significantly more infected by T. gondii than the lambs (< 1 year) in both species (p < 0.05). Conclusions: These findings indicated that food animals are highly exposed to T. gondii in Lebanon and could be potentially a major risk factor of T. gondii infection to humans. Consequently, national prophylactic strategies should be implemented to control and to prevent T. gondii transmission between animals and humans.