Background: Lactic Acid Bacteria (LAB) are of special interest in the food industry due to their ability to produce metabolites. Among them, bacteriocins, which can inhibit the growth of altering microorganisms, and pathogens in a wide variety of foods, are considered safe for human consumption and are used as preservatives. Objectives: Evaluate the effect of a bacteriocin found by in silico methods on the microbiota present in Antioquian soft cheese. Methods: In this research, we design a synthetic bacteriocin, called Bac 22, found in the genome of Lactobacillus casei using the genomic mining methodology and bioinformatics tools. We also conducted a preliminary biological and hemolytic activities studies of the Bac 22 toward the microbiota present in the Antioquian soft cheese (Quesito Antioqueño). Results: The bacteriocin Bac 22 at a concentration of 100 μM presented a hemolytic capacity lower than 1% and reduced the CFU / g of total coliforms significantly when added to Antioquian soft cheese for eight days. Conclusions: The Bac 22 demonstrated a positive potential effect over the shelf life of a dairy product, such as the Antioquian soft cheese.

There is increasing evidence that the diet and nutritional status of women during pregnancy and lactation can modulate the microbiota of their milk and, therefore, the microbiota of the infant. An observational, descriptive, and cross-sectional study was carried out in a group of lactating women. Dietary intake during gestation and the first trimester of lactation was evaluated, and the microbiota was analyzed by 16S ribosomal RNA (rRNA) sequencing using the Illumina platform. Globally, Streptococcus spp. (32%), Staphylococcus spp. (17.3%), Corynebacterium spp. (5.1%) and Veillonella spp. (3.1%) were the predominant bacterial genera. The consumption of simple carbohydrates in gestation (rho = 0.55, p ≤ 0.01) and lactation (rho = 0.50, p ≤ 0.01) were positively correlated with Enterobacter spp. In lactation, a negative correlation was observed between the intake of simple carbohydrates and the genus Bifidobacterium spp. (rho = −0.51 p ≤ 0.01); furthermore, a positive correlation was identified between the intake of folic acid and Akkermansia spp. (rho = 0.47, p ≤ 0.01). Amplicon sequence variants (ASVs) associated with the delivery mode, employment relationship, the baby’s gender, birth weight, the Body Mass Index (BMI) of the breastfeeding woman, and gestational weight gain were recovered as covariates in a linear mixed model. The results of this research showed that the maternal nutritional status and diet of women during gestation and lactation could modulate the microbiota of breast milk.