Various environmental contaminants including heavy metals, pesticides and antibiotics can contaminate food and water, leading to adverse effects on human health, such as inflammation, oxidative stress and intestinal disorder. Therefore, remediation of the toxicity of foodborne contaminants in human has become a primary concern. Some probiotic bacteria, mainly Lactobacilli, have received a great attention due to their ability to reduce the toxicity of several contaminants. For instance, Lactobacilli can reduce the accumulation and toxicity of selective heavy metals and pesticides in animal tissues by inhibiting intestinal absorption of contaminants and enhancing intestinal barrier function. Probiotics have also shown to decrease the risk of antibiotic-associated diarrhea possibly via competing and producing antagonistic compounds against pathogenic bacteria. Furthermore, probiotics can improve immune function by enhancing the gut microbiota mediated anti-inflammation. Thus, these probiotic bacteria are promising candidates for protecting body against foodborne contaminants-induced toxicity. Study on the mechanism of these beneficial bacterial strains during remediation processes and particularly their interaction with host gut microbiota is an active field of research. This review summarizes the current understanding of the remediation mechanisms of some probiotics and the combined effects of probiotics and gut microbiota on remediation of foodborne contaminants in vivo.

In this study, Lactobacillus fermentum DM7-6 (DM7-6), Lactobacillus plantarum DM9-7 (DM9-7), and Bacillus subtilis YF9-4 (YF9-4) were isolated from traditional fermented products. The survival rate of DM7-6, DM9-7, and YF9-4 in simulated intestinal gastric fluid reached 61.29%, 44.82%, and 55.26%, respectively. These strains had inhibition ability against common pathogens, and the inhibition zone diameters were more than 7 mm. Antioxidant tests showed these strains had good scavenging capacity for superoxide anion, hydroxyl radical and DPPH, and the total reduction capacity reached 65%. Then DM7-6, DM9-7 and YF9-4 were fed to broilers to study the effects on antioxidant capacity, immune response, biochemical indices, tissue morphology, and gut microbiota. 180 healthy broilers were allocated randomly into six experimental groups. SOD, GSH-Px, and T-AOC in broilers serum were detected, and the results showed probiotics significantly improve antioxidant capacity compared to CK group, while antibiotics showed the opposite result. Besides, IgA, IgM, IgG, TNF-α, and IL-2 indicated it could significantly improve immunity by adding probiotics in broilers diets. However, antibiotics reduced immunoglobulin levels and enhanced inflammation index. Biochemical indicators and tissue morphology showed probiotics had a protective effect on metabolic organs. Gut microbiota analysis proved antibiotics could significantly decrease microbial community diversity and increase the proportion of opportunistic pathogens, while probiotics could improve the diversity of gut microbiota and promote the colonization of beneficial microorganisms. In summary, probiotics DM7-6, DM9-7, and YF9-4 can improve the broiler’s health by improving antioxidant capacity and immune function, regulating gut microbiota, and can be used as alternative probiotics for antibiotics-free breeding of broilers.

To study the relationship between the microbial community structure and the quality of alfalfa silage by adding alfalfa-fermented green juice (aFGJ), the Box–Behnken design was used to optimize the process of preparing aFGJ. High-throughput sequence technology was used to detected the microbial community structure of aFGJ and silage samples, and two silage experiments were designed: silage with aFGJ (LZQC) and silage with no addition (CK). In addition, the chemical composition and fermentation quality of silage samples at different times were determined. The result showed that the optimal aFGJ culture condition for LAB quantity was an addition of 2.6% glucose to alfalfa green juice and an anaerobic culture at 35 °C for 49 h, and the number of viable bacteria can reach 8.0 × 10⁸ cfu·mL⁻¹. The main microorganisms (species level) were Lactobacillus brevis (57.63%) and Lactobacillus plantarum (37.31%). There was a significant increase in the relative abundance of Pediococcus. pentosaceus and L. plantarum and a reduction in L. brevis after silage for 70 days with the added aFGJ; meanwhile, the chemical composition (DM losses, aNDF) and fermentation quality (pH, NH₃-N/TN, LA) were significantly better than that of the CK group. The addition of aFGJ changed the types and abundance of microbial communities, increased the number of beneficial lactic acid bacteria (LAB), and decreased the number of harmful bacteria, which had a significant effect on the quality of the silage.

In recent years, the overuse of antibiotics in livestock feed has raised significant public health concerns. As a result, antibiotic-free breeding has become a key focus of sustainable agricultural development. Efforts to replace antibiotics in feed have largely focused on plant-derived...