Response of Fecal Bacterial Flora to the Exposure of Fumonisin B1 in BALB/c Mice

Effect of Fumonisin B1 and Hydrolyzed FB1 Exposure on Intestinal and Hepatic Toxicity in BALB/c Mice

Fumonisins, a class of mycotoxins, pose significant health risks due to widespread contamination. The presence of masked mycotoxins complicates risk assessments because of insufficient regulation and potential toxicity as well as in vivo transformation. This study aims to compare the toxic effects of continuous exposure to fumonisin B1 (FB1) and hydrolyzed FB1 (HFB1) on the gut-liver axis in mice. After 21 d of exposure to FB1 and HFB1, the distributions of FB1 and its metabolites in mice were analyzed, and their effects on intestinal morphology, gut microbial diversity, short-chain fatty acids (SCFAs), inflammatory factors, and hippocampal metabolites were assessed. The results revealed that the highest concentrations of FB1 (61.87%) and HFB1 (53.56%) were detected in the cecum, followed by the colon. Exposure to FB1 and HFB1 resulted in compromised intestinal integrity, villi atrophy, elevated levels of inflammatory factors, and decreased total SCFAs. Both FB1 and HFB1 led to a significant reduction in the Firmicutes to Bacteroides ratio. Blood biochemical analysis and liver metabolomics indicated that FB1 and HFB1 also induced disturbances in the liver homeostasis. The complex correlations observed between the metabolomic and microbiota results underscore the involvement of the gut-liver axis in the disruption induced by these two mycotoxins. These findings highlight the systemic effects of FB1 and HFB1 on liver and gut health, providing valuable insights for further research into their mechanisms and health implications.

Effects of Low and High Doses of Deoxynivalenol on Growth Performance, Blood Biochemistry, Histology, Metabolites, and Microbial Community in Adult Rats

Deoxynivalenol (DON) is a widespread mycotoxin which contaminates several crops, including maize, wheat, and barley. In this study, we investigated the effects of orally administered DON on growth performance, blood biochemistry, histology, the gut microbiome, and metabolism in rats. Six-week-old rats, acclimatized for one week, were subjected to different dietary treatments for 42 days, as follows: CON (control): 0.9% saline; T1: 0.5 ppm DON; T2: 50 ppm DON; and T3: 100 ppm DON. The T3 group had the lowest final body weight (298.5 ± 3.69 g) and average daily gain compared with the control group (338.9 ± 6.43 g, p < 0.05). The feed conversion ratio was highest in the T3 group (4.28 ± 0.28) compared with that in the control group (3.12 ± 0.13, p < 0.05). DON treatment significantly reduced serum levels of creatinine, amylase, urea nitrogen, and alkaline phosphatase, but not alanine aminotransferase. Fibrosis and apoptosis were exacerbated in various tissues with increasing DON concentration. The metabolite profiles of several tissues were significantly different in the DON-treated and control groups. In the cecum, DON treatment increased the abundance of Desulfobacteria, while decreasing that of Firmicutes. Our results indicate that DON levels above the maximum residue limit have serious health consequences for animals.

Effects of Deoxynivalenol Contamination on Growth Performance, Blood Biochemistry, Histology, Metabolomics, and the Microbiota: A Subacute Dose Oral Toxicity Study in Rats

Deoxynivalenol (DON), one of the most common mycotoxins, is frequently found in foods. This study investigated the effects of orally administered DON on the blood biochemical parameters, growth performance, histology, microbial composition, and metabolism of rats. After a 1-week adaptation period, 4-week-old rats were administered 0.9% saline (control), 1 mg/L DON (T1), 10 mg/L DON (T2), or 50 mg/L DON (T3) by gavage for 49 days. The DON-treated groups had significantly lower body weights than the control group (p < 0.05). Blood alkaline phosphatase, phosphate, cholesterol, amylase, and creatinine levels differed significantly between the DON-treated and control groups (p < 0.05). With increasing DON doses, fibrosis and apoptosis were observed in several tissues. In terms of metabolites, the bile acid biosynthesis pathway emerged as a potential biomarker, while the tryptophan metabolism pathway was found to be the most affected. The fecal microbiota showed significant differences in both alpha and beta diversity between the DON-treated and control groups (p < 0.05). In the cecal and fecal microbiota, the relative abundance of Firmicutes increased in the control and T1 groups, whereas Bacteroidota and Campylobacterota were more abundant in the T2 and T3 groups. In conclusion, our results showed that high DON exposure induces several dose-dependent adverse effects on rats.

Insights into the intestinal toxicity of foodborne mycotoxins through gut microbiota: A comprehensive review

Mycotoxins, which are fungal metabolites, pose a significant global food safety concern by extensively contaminating food and feed, thereby seriously threatening public health and economic development. Many foodborne mycotoxins exhibit potent intestinal toxicity. However, the mechanisms underlying mycotoxin-induced intestinal toxicity are diverse and complex, and effective prevention or treatment methods for this condition have not yet been established in clinical and animal husbandry practices. In recent years, there has been increasing attention to the role of gut microbiota in the occurrence and development of intestinal diseases. Hence, this review aims to provide a comprehensive summary of the intestinal toxicity mechanisms of six common foodborne mycotoxins. It also explores novel toxicity mechanisms through the "key gut microbiota-key metabolites-key targets" axis, utilizing multiomics and precision toxicology studies with a specific focus on gut microbiota. Additionally, we examine the potential beneficial effects of probiotic supplementation on mycotoxin-induced toxicity based on initial gut microbiota-mediated mycotoxicity. This review offers a systematic description of how mycotoxins impact gut microbiota, metabolites, and genes or proteins, providing valuable insights for subsequent toxicity studies of mycotoxins. Furthermore, it lays a theoretical foundation for preventing and treating intestinal toxicity caused by mycotoxins and advancing food safety practices.

Gut-Faecal Microbial and Health-Marker Response to Dietary Fumonisins in Weaned Pigs

This study investigated effects of dietary fumonisins (FBs) on gut and faecal microbiota of weaned pigs. In total, 18 7-week-old male pigs were fed either 0, 15 or 30 mg FBs (FB1 + FB2 + FB3)/kg diet for 21 days. The microbiota was analysed with amplicon sequencing of the 16S rRNA gene V3-V4 regions (Illumina MiSeq). Results showed no treatment effect (p > 0.05) on growth performance, serum reduced glutathione, glutathione peroxidase and malondialdehyde. FBs increased serum aspartate transaminase, gamma glutamyl-transferase and alkaline phosphatase activities. A 30 mg/kg FBs treatment shifted microbial population in the duodenum and ileum to lower levels (compared to control (p < 0.05)) of the families Campylobacteraceae and Clostridiaceae, respectively, as well as the genera Alloprevotella, Campylobacter and Lachnospiraceae Incertae Sedis (duodenum), Turicibacter (jejunum), and Clostridium sensu stricto 1 (ileum). Faecal microbiota had higher levels of the Erysipelotrichaceae and Ruminococcaceae families and Solobacterium, Faecalibacterium, Anaerofilum, Ruminococcus, Subdoligranulum, Pseudobutyrivibrio, Coprococcus and Roseburia genera in the 30 mg/kg FBs compared to control and/or to the 15 mg/kg FBs diets. Lactobacillus was more abundant in the duodenum compared to faeces in all treatment groups (p < 0.01). Overall, the 30 mg/kg FBs diet altered the pig gut microbiota without suppressing animal growth performance.

Effects of Fumonisin B and Hydrolyzed Fumonisin B on Growth and Intestinal Microbiota in Broilers

Fumonisins are mainly produced by Fusarium verticillioides and proliferatum, which causes a variety of toxicities in humans and animals, including fumonisin Bs (FBs) as the main form. After they are metabolized by plants or microorganisms, modified fumonisins are difficult to detect by conventional methods, which result in an underestimation of their contamination level. Fumonisins widely contaminate maize and maize products, especially in broiler feed. As an economically important food, broilers are often adversely affected by mycotoxins, leading to food safety hazards and high economic losses. However, there are few studies regarding the adverse effects of FBs on broiler growth and health, especially modified FBs. Our data shows that after exposure to FBs or hydrolyzed fumonisin Bs (HFBs), the body weight and tissue weight of broilers decreased significantly, especially the testes. Moreover, they significantly affect the intestinal microbiota and the relative abundance of bacteria from phylum-to-species levels, with the differentially affected bacteria mainly belonging to Firmicutes and Proteobacteria. Our findings suggest that both the parent and hydrolyzed FBs could induce growth retardation, tissue damage and the imbalance of intestinal microbiota in broilers. This indicated that the harmful effects of HFBs cannot be ignored during food safety risk assessment.