Bacteriocins: Potential for Human Health

Abstract

Due to the challenges of antibiotic resistance to global health, bacteriocins as antimicrobial compounds have received more and more attention. Bacteriocins are biosynthesized by various microbes and are predominantly used as food preservatives to control foodborne pathogens. Now, increasing researches have focused on bacteriocins as potential clinical antimicrobials or immune-modulating agents to fight against the global threat to human health. Given the broad- or narrow-spectrum antimicrobial activity, bacteriocins have been reported to inhibit a wide range of clinically pathogenic and multidrug-resistant bacteria, thus preventing the infections caused by these bacteria in the human body. Otherwise, some bacteriocins also show anticancer, anti-inflammatory, and immune-modulatory activities. Because of the safety and being not easy to cause drug resistance, some bacteriocins appear to have better efficacy and application prospects than existing therapeutic agents do. In this review, we highlight the potential therapeutic activities of bacteriocins and suggest opportunities for their application.

Figure 1

Bacteriocins protect the human body from infection by inhibiting a wide variety of pathogenic microorganisms via different mechanisms. (a) For bacteria, bacteriocins can directly kill pathogenic bacteria by inhibiting the bacteria cell wall biosynthesis by complexing the lipid II and forming the pore in cell membrane, disrupting bacterial population sensing as a signaling molecule, or enters the cell via a transporter and interacts with critical enzymes (e.g., ATP-dependent protease). This eliminates the presence of pathogenic bacteria in the organism and reduces their migration to various extraintestinal organs, i.e., the lung, kidney, and liver. (b) For viruses, bacteriocins can inhibit the proliferation or transfer of viruses by blocking the synthesis of glycoproteins in the late stage of virus replication. (c) For parasites, bacteriocins can inhibit the parasites through mitochondrial membrane depolarization and reactive oxygen species production.

Figure 2

Bacteriocins inhibit the development of cancer by inhibiting the growth of cancer cells through various mechanisms. Bacteriocins increase the fluidity of cell membranes and form ion channels on cancer cell membranes, increasing the release of LDH. Bacteriocins promote the accumulation of intracellular ROS, increase the apoptotic index (bax/bcl2), reduce the expression of FOXM1 and MMP9, inhibit mitochondrial energy metabolism and glycolysis, reduce its energy supply leading to apoptosis and necrosis, or inhibit its migration and proliferation, which ultimately promotes the apoptosis and necrosis, inhibiting the migration and proliferation of cancers.

Figure 3

Anti-inflammation and immunomodulation effect of bacteriocins. (a) For the anti-inflammatory effect, some bacteriocins can increase anti-inflammatory cytokine levels, decrease proinflammatory cytokine levels, and maintain the balance between immune cells by inhibiting the activation of inflammatory signaling pathways in a state of inflammation. Some bacteriocins can act directly on pathogenic bacteria or reduce colonization of pathogenic bacteria by stimulating the production of antimicrobial substances. Some bacteriocins can promote the expression of intestinal tight junction proteins and strengthen the intestinal barrier. (b) For immune regulation, some bacteriocins can promote the body to produce inflammatory cytokines and promote the phagocytosis of macrophages, thus boosting the immunity and achieving immune regulation in the immunosuppressive state.