Background: Lactiplantibacillus plantarum is a widely studied probiotic species; however, probiotic characteristics and safety profiles are strain-specific, requiring independent evaluation. This study characterized Lactiplantibacillus plantarum ATA-LPC98052 as a candidate probiotic raw material. Methods: ATA-LPC98052 was evaluated for hemolysis, acid/bile tolerance, Caco-2 adhesion, cytotoxicity, and storage stability. Subacute oral safety was assessed in Wistar rats by gavage for 28 days at 1.2 × 10¹¹ CFU/kg/day; the study design incorporated selected principles of OECD Test Guideline 407. Clinical, hematological, biochemical, organ-weight, and macroscopic endpoints were evaluated. Fecal microbiota was analyzed by 16S rRNA sequencing; WGS was used for taxonomic confirmation and genomic safety screening. Results: ATA-LPC98052 was γ-hemolytic and maintained 60% viability at pH 1.5 and 96% at pH 5.0, while viability ranged from 74% to 82% across 0.1–0.5% bile salt concentrations. Caco-2 cell viability was 99%, adhesion exceeded 90%, and the lyophilized preparation remained stable for 15 months, maintaining 9.6 log₁₀ CFU/g. Repeated oral administration caused no mortality or consistent treatment-related toxicological pattern. Longitudinal microbiota analysis showed no significant treatment × time effects on alpha diversity or Bray–Curtis community structure, and no genus-level MaAsLin2 association was FDR-significant. WGS confirmed L. plantarum identity and no contamination; ResFinder detected no acquired antimicrobial resistance determinants meeting specified thresholds, whereas CARD/RGI identified low-identity qacJ and vanY homologs requiring cautious interpretation. Conclusion: ATA-LPC98052 demonstrated favorable in vitro probiotic characteristics, technological stability, gut microbiota-modulating potential, and a favorable subacute safety profile under the tested conditions; however, microbiota findings were exploratory, and phenotypic MIC testing remains warranted.

Aim: This study aims to perform microbiological analyses of commercial and homemade infant formulas used in complementary infant feeding and to determine the antibiotic resistance profiles of pathogenic bacteria isolated from these formulas. Materials and Methods: Samples were taken from various homemade and commercially available infant formulas. The microbial content and antibiotic resistance profiles of the isolated pathogenic strains were analyzed using standard microbiological methods. Results: The study found that the microbiological quality of homemade infant formulas was lower compared to commercial formulas. It was observed that the microbiological quality of infant formulas was significantly affected by prolonged storage. Notably, the presence of pathogenic bacteria with multiple antibiotic resistances was detected in some samples, indicating potential health risks for infants. Conclusion: The study highlights the importance of microbiological safety in the preparation and selection of infant formulas. Additionally, the emergence of multi-antibiotic resistant bacteria underscores the necessity for increased awareness and the establishment of stringent standards.

Background/Objectives: Atopic dermatitis (AD) is associated with gut dysbiosis linked to early-life antibiotic use and Staphylococcus aureus colonization. Gum Arabic (GA), a prebiotic, may modulate this dysbiosis and influence AD-related microbial balance. This study evaluated whether GA could support AD-associated probiotics-Lactobacillus casei, Bifidobacterium bifidum, and Bifidobacterium infantis-under amoxicillin- or azithromycin-containing conditions, examined the response of S. aureus under the same screening conditions, and developed GA-phospholipid-based semisolid carriers for topical application. Methods: Probiotic strains were cultured with 1–5% GA in the presence and absence of antibiotics, and viable cell counts were assessed. Sixteen topical formulations containing propylene glycol or isopropyl myristate in a hydrogenated phosphatidylcholine base were prepared and screened for rheological properties and galactose release using in vitro release testing (IVRT) and HPLC-UV. Results: GA at 1–2% concentrations promoted probiotic growth in antibiotic-free conditions. GA preserved B. infantis viability under azithromycin exposure in this in vitro screening model. For S. aureus, numerical CFU differences were observed between antibiotic-only and GA-containing conditions; however, the present screening design was not intended to determine antibiotic interaction outcomes. Formulations F14 (2% GA + 7% IPM) and F15 (3% GA + 7% IPM) exhibited optimal spreadability. IVRT showed that 6 h cumulative galactose release varied by formulation (F6 > F10 > F14 > F15). Conclusions: GA demonstrated dose-dependent prebiotic activity and preserved B. infantis viability under azithromycin exposure in this in vitro screening model. For S. aureus, the observed CFU differences between antibiotic-only and GA-containing conditions should be considered exploratory only and do not allow for conclusions regarding interference with antibiotic efficacy. Optimized GA-HPC systems with suitable rheological and release characteristics represent promising candidates for further preclinical investigation.