As one of the adhesion-related surface factors on the cell wall of Lactobacillus strains, Leu-Pro-x-Thr-Gly (LPxTG) motif anchored proteins play a critical role in adhesion and molecular cross-talk with the host in the gastrointestinal tract (GIT). This study allows to understand that the combination of LPxTG-motif surface proteins (LMP) and fructooligosaccharides (FOS) can have a better promoting effect on lactic acid bacteria. In this study, molecular docking and molecular dynamics simulations were employed to investigate the interaction properties of LMP from Limosilactobacillus reuteri SH23 with small nutrient molecules in the host GIT. The thermodynamic parameters ΔG⁰, ΔH⁰, and ΔS⁰ were calculated as −4.850 kJ/mol, −219.071 kJ/mol, and −718.501 J/(mol∙K), respectively, for a binding constant of 1.414 × 10⁴ μmol/L at 298.15 K. Fluorescence spectroscopy and circular dichroism spectroscopy were also utilised to study the interaction of LMP with the small nutrient molecules. It was found that LMP interacts with the small nutrient molecule FOS primarily through van der Waals and electrostatic forces. The transition from β-folding and random coiling to α-helix and β-sheet also indicates structural changes in the protein during the binding process. Furthermore, the binding of LMP to FOS not only improved the adhesion of the strain to intestinal epithelial cells and increased the auto-aggregation of the strain, but also promoted the growth of L. reuteri SH23. These findings provide a better understanding of Lactobacillus and host interactions at the cell surface protein level.

Lipoteichoic acid (LTA), a bacterial cell surface macromolecule, plays a key role in probiotic–host interactions by engaging host pattern recognition receptors in the gastrointestinal mucosa. This study investigates the potential of Lactiplantibacillus plantarum LTA in combating intestinal pathogens and supporting gut health. We demonstrate that L. plantarum LTA, acting as a biosurfactant, significantly inhibits biofilm formation by various intestinal pathogens, including Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes. This is achieved by disrupting biofilm structures, reducing extracellular polymer secretion, and downregulating biofilm-related gene expression. Additionally, LTA effectively prevents pathogen adhesion to Caco-2 cells and reduces Escherichia coli-induced apoptosis. LTA also modulates macrophage inflammation by regulating cytokine secretion and decreasing NO and ROS production through the TLR4-MAPK-NF-κB signaling pathway. These findings provide valuable insights into the mechanisms by which L. plantarum LTA supports gut health and highlight its potential applications in preventing intestinal pathogen colonization and enhancing immune modulation.

The milk fat globule membrane (MFGM) is a three-layered membrane that surrounds milk fat globules. Its main components include proteins, carbohydrates, and lipids, which are mainly derived from the mammary gland cell membrane. Different milk sources vary in the composition of MFGM proteins, which have good emulsifying properties, gastrointestinal stability and safety. Some MFGM proteins have diverse bioactivities including anti-inflammatory, antiviral and intestine regulatory effects and enhancing the exercise performance of muscles. This paper reviews the composition, physicochemical properties and bioactivities of MFGM proteins, which will provide a reference for the research and application of MFGM proteins in the dairy industry and related food additives.

In this study, 10 novel anti-inflammatory peptides were identified from duck liver, and their molecular mechanism was demonstrated based on machine learning and molecular docking. Using Sephadex G-15 gel chromatography separation, reversed-phase high-performance liquid chromatography purification, liquid chromatography-tandem mass spectrometry identification, and BIOPEP database comparison, 10 novel anti-inflammatory peptides were initially found. Their splendid angiotensin-converting enzyme (ACE) inhibition and anti-inflammatory properties were confirmed by machine learning. With binding energies less than –20.93 kJ/mol, molecular docking revealed that they could efficiently bind to the active pockets of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), cyclooxygenase 2 (COX-2), and nuclear factor κB (NF-κB) proteins with efficiency, indicating that the compounds can spontaneously form complexes through hydrogen bonding and hydrophobic interactions with the protein binding pockets. In the lipopolysaccharide-induced RAW264.7 cell model, the release of NO, TNF-α, and IL-6 and the mRNA expression of inflammatory factors (TNF-α, IL-6, COX-2, and NF-κB) were significantly inhibited by these peptides. We concluded it might be due to their anti-inflammatory effects by inhibiting the protein phosphorylation of inhibitor of NF-κB (IκBα) in the cytoplasm and preventing the translocation of NF-κB p65 in the cytoplasm to the nucleus, thereby regulating the NF-κB signaling pathway. This study is essential for the screening of anti-inflammatory peptides and the investigation of the mechanism of action.

Lactic acid bacteria (LAB) fermentation is the simplest and safest way of food preservation, and the use of probiotics in yoghurt could provide dairy products with unique flavors, textures and health benefits. In this study, Lactobacillus bulgaricus, Streptococcus thermophilus, L. reuteri DSMZ 8533 and the potential probiotic strain L. plantarum A3 were used for the milk fermentation. Results found the texture properties such as hardness, consistency, and viscosity of the yoghurt were enhanced in the mixed culture condition. Furthermore, components like amino acid (leucine), vanilla (vanillin), C_18:3n6 (unsaturated fatty acids) were also accumulated in L. plantarum A3 fermented yoghurt, which leads to the significant sensory profiling difference compared with the former plain yoghurt. All these results proved L. plantarum A3 is a potential probiotic strain which could enhance the sensory and nutrition profiling of the fermented milk. Future work still needs to be done on the synergistic interaction between the traditional strains and the probiotics during the fermentation process.