In vivo AFB1 detoxification by Lactobacillus fermentum LC5/a with chlorophyll and immunopotentiating activity in albino mice

Differential Regulatory Effects of Probiotics on Bone Metabolism by the Status of Bone Health and Delivery Route

Probiotics are known to have favorable effects on human health. Nevertheless, probiotics are not always beneficial and can cause unintended adverse effects such as bacteremia and/or inflammation in immunocompromised patients. In the present study, we investigated the effects of probiotics on the regulation of bone metabolism under different health conditions and delivery routes. Intragastric administration of Lactiplantibacillus plantarum to ovariectomized mouse models for mimicking post-menopausal osteoporosis in humans substantially ameliorated osteoporosis by increasing bone and mineral density. In contrast, such effects did not occur in normal healthy mice under the same condition. Interestingly, however, intraperitoneal administration of L. plantarum induced bone destruction by increasing osteoclast differentiation and decreasing osteoblast differentiation. Furthermore, when L. plantarum was implanted into mouse calvarial bone, it potently augmented bone resorption. Concordantly, L. plantarum upregulated osteoclastogenesis and downregulated osteoblastogenesis in in vitro experiments. These results suggest that L. plantarum can have distinct roles in the regulation of bone metabolism depending on bone health and the delivery route.

Association between anaemia and aflatoxin B1 and fumonisin B1 exposure in HIV-infected and HIV-uninfected pregnant women from Harare, Zimbabwe

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are poisons that contaminate poorly stored staple foods in resource-limited settings. Antenatal AFB1 and FB1 exposure may cause anaemia. We aimed to determine the associations of urinary aflatoxin M1 (AFM1) and FB1, biomarkers of AFB1 and FB1 exposure, respectively, with erythrocyte parameters and anaemia. A retrospective cross-sectional study was conducted in 68 HIV-infected and 61 HIV-uninfected pregnant women ≥ 20 weeks gestational age in Harare, Zimbabwe. AFM1 and FB1 were measured in urine via competitive ELISA, and levels were grouped into tertiles. The erythrocyte parameters assessed were haemoglobin (Hb), mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red blood cell (RBC), haematocrit (HCT), and red blood cell distribution width. Associations of urinary AFM1 and FB1 with erythrocyte parameters, and anaemia were assessed in a multiple regression controlled for potential confounders. The presence of FB1 in urine decreased Hb levels in all women (β= -0.98, 95% CI: -1.94, 0.02) and HIV-uninfected (β= -1.99, 95% CI: -3.71, -0.26). FB1 tertile 3 decreased Hb levels (β= -0.88, 95% CI: -1.74, 0.01) and HCT levels (β= -2.65, 95% CI: -5.26, 0.03) in HIV-infected. AFM1 tertile 2 decreased RBC levels in HIV-infected (β= -0.34, 95% CI: -0.71, -0.03). The presence of FB1 in urine increased anaemia risk in HIV-uninfected (OR: 10.68 95% CI: 1.02, 112.34). AFM1 tertile 2 increased macrocytic anaemia risk in HIV-infected (OR: 13.72, 95% CI: 0.92, 203.55). There is need to ensure food safety through monitoring and nutritional interventions to improve maternal-infant health outcomes.

Aflatoxin B1 exposure causes splenic pyroptosis by disturbing the gut microbiota-immune axis

Aflatoxin B1 (AFB1) causes serious immunotoxicity and has attracted considerable attention owing to its high sensitivity and common chemical-viral interactions in living organisms. However, the sensitivity of different species to AFB1 widely varies, which cannot be explained by the different metabolism in species. The gut microbiota plays a crucial role in the immune system, but the interaction of the microbiota with AFB1-induced immunotoxicity still needs to be determined. Our results indicated that AFB1 exposure disrupted the structure of the gut microbiota and damaged the gut barrier, which caused translocation of microbiota metabolites, lipopolysaccharides, to the spleen. Subsequently, pyroptosis of the spleen was activated. Interestingly, AFB1 exposure had little effect on the splenic pyroptosis of pseudo-germfree mice (antibiotic mixtures eliminated their gut microbiota, ABX). Then, fecal microbiota transplant (FMT) and sterile fecal filtrate (SFF) were employed to validate the function of the gut microbiota and its metabolites in AFB1-induced splenic pyroptosis. The AFB1-disrupted microbiota and its metabolites significantly promoted splenic pyroptosis, which was worse than that in control mice. Overall, AFB1-induced splenic pyroptosis is associated with the gut microbiota and its metabolites, which was further demonstrated by FMT and SFF. The mechanism of AFB1-induced splenic pyroptosis was explored for the first time, which paves a new way for preventing and treating the immunotoxicity from mycotoxins by regulating the gut microbiota.

An Insight into Different Experimental Models used for Hepatoprotective Studies: A Review

Numerous factors, including exposure to harmful substances, drinking too much alcohol, contracting certain hepatitis serotypes, and using specific medicines, contribute to the development of liver illnesses. Lipid peroxidation and other forms of oxidative stress are the main mechanisms by which hepatotoxic substances harm liver cells. Pathological changes in the liver include a rise in the levels of blood serum, a decrease in antioxidant enzymes, as well as the formation of free radical radicals. It is necessary to find pharmaceutical alternatives to treat liver diseases to increase their efficacy and decrease their toxicity. For the development of new therapeutic medications, a greater knowledge of primary mechanisms is required. In order to mimic human liver diseases, animal models are developed. Animal models have been used for several decades to study the pathogenesis of liver disorders and related toxicities. For many years, animal models have been utilized to investigate the pathophysiology of liver illness and associated toxicity. The animal models are created to imitate human hepatic disorders. This review enlisted numerous hepatic damage in vitro and in vivo models using various toxicants, their probable biochemical pathways and numerous metabolic pathways via oxidative stressors, different serum biomarkers enzymes are discussed, which will help to identify the most accurate and suitable model to test any plant preparations to check and evaluate their hepatoprotective properties.

Association of intestinal dysbiosis with susceptibility to multiple sclerosis: Evidence from different population studies (Review)

Understanding the relationship between microorganisms that live in our intestines and neuroinflammatory and neurodegenerative pathologies of the central nervous system (CNS) is essential, since they have been shown to have an immunomodulatory effect in neurological disorders, such as multiple sclerosis (MS). The gut microbiota can be affected by several environmental factors, including infections, physical and emotional stress and diet, the latter known as the main modulator of intestinal bacteria. An abrupt shift in the gut microbiota composition and function is known as dysbiosis, a state of local and systemic inflammation produced by pathogenic bacteria and its metabolites responsible for numerous neurological symptoms. It may also trigger neuronal damage in patients diagnosed with MS. Intestinal dysbiosis affects the permeability of the intestine, allowing chronic low-grade bacterial translocation from the intestine to the circulation, which may overstimulate immune cells and cells resident in the CNS, break immune tolerance and, in addition, alter the permeability of the blood-brain barrier (BBB). This way, toxins, inflammatory molecules and oxidative stress molecules can pass freely into the CNS and cause extensive damage to the brain. However, commensal bacteria, such as the Lactobacillus genus and Bacteroides fragilis, and their metabolites (with anti-inflammatory potential), produce neurotransmitters such as γ-aminobutyric acid, histamine, dopamine, norepinephrine, acetylcholine and serotonin, which are important for neurological regulation. In addition, reprogramming the gut microbiota of patients with MS with a healthy gut microbiota may help improve the integrity of the gut and BBB, by providing clinically protective anti-inflammatory effects and reducing the disease's degenerative progression. The present review provides valuable information about the relationship between gut microbiota and neuroinflammatory processes of the CNS. Most importantly, it highlights the importance of intestinal bacteria as an environmental factor that may mediate the clinical course of MS, or even predispose to the outbreak of this disease.

Aflatoxin B1 can aggravate BALB/c mice allergy to ovalbumin through changing their Th2 cells immune responses

Foods contaminated by Aflatoxin B₁ (AFB₁) frequently happen in the world and can cause a lot healthy damages to human beings, meanwhile, some of these foods are easily irritate food allergy. To investigate the effect of AFB₁ exposure on food allergy, three doses of AFB₁ were set, including 0.3 μg/kg · bw (LDAF), 7.5 μg/kg · bw (MDAF), and 100.0 μg/kg · bw (HDAF), respectively; food allergy model was constructed by the BALB/c mice allergy to ovalbumin (OVA). The changes of titer in OVA-specific immunoglobulin E (IgE), IgG, IgG1, IgG2a, as well as level of the mMCP-1 in sera were determined by enzyme linked immunosorbent assay (ELISA), respectively; the levels of interleukin (IL-4, IL-5, IL-13) and interferon (IFN)-γ in spleen were separately assessed using ELISA kits, and their relative genes expression were verified by Real-time fluorescence quantitative PCR (Q-PCR); the population of Th1/Th2/Treg cells were analyzed by flow cytometry. Results showed that when OVA-allergic mice were exposed to AFB₁, the production of OVA-specific IgE, IL-4, IL-5 and IL-13, and mMCP-1 were all increased, whereas the level of IFN-γ was decreased; the Th1/Th2 balance was disrupted and the development of Th cells tilted to the Th2 phenotype. The study would contribute to further understand the risk of fungal toxins in food allergy.

Lactobacillus plantarum and Deoxynivalenol Detoxification: A Concise Review

ABSTRACT

Mycotoxins are toxic secondary fungal metabolites that contaminate feeds, and their levels remain stable during feed processing. The economic impact of mycotoxins on animal production happens mainly due to losses related to direct effects on animal health and trade losses related to grain rejection. Deoxynivalenol (DON) is a trichothecene mycotoxin that has contaminated approximately 60% of the grains worldwide. Ingestion of DON induces many toxic effects on human and animal health. Detoxification strategies to decrease DON levels in food and feeds include physical and chemical methods; however, they are not very effective when incorporated into the industrial production process. A valuable alternative to achieve this aim is the use of lactic acid bacteria. These bacteria can control fungal growth and thus overcome DON production or can detoxify the mycotoxin through adsorption and biotransformation. Some Lactobacillus spp. strains, such as Lactobacillus plantarum, have demonstrated preventive effects against DON toxicity in poultry and swine. This beneficial effect is associated with a binding capacity of lactic acid bacteria cell wall peptidoglycan with mycotoxins. Moreover, several antifungal compounds have been isolated from L. plantarum supernatants, including lactic, acetic, caproic, phenyl lactic, 3-hydroxylated fatty, and cyclic dipeptide acids. Biotransformation of DON by L. plantarum into other products is also hypothesized, but the mechanism remains unknown. In this concise review, we highlight the use of L. plantarum as an alternative approach to reduce DON levels and toxicity. Although the action mechanism of L. plantarum is still not fully understood, these bacteria are a safe, efficient, and low-cost strategy to reduce economic losses from mycotoxin contamination cases.

HIGHLIGHTS

Isolation and Aflatoxin B1-Degradation Characteristics of a Microbacterium proteolyticum B204 Strain from Bovine Faeces

Aflatoxin B₁ (AFB₁) is one of the most harmful mycotoxins, raising serious global health and economic problems. Searching for biological approaches for effective and safe AFB₁ degradation is imminent. In our study, Microbacterium proteolyticum B204 isolated from bovine faeces degraded 77% of AFB₁ after 24 h, becoming the first reported bacteria from the Microbacterium family to possess AFB₁ degradation characteristics. Temperature variation showed little effect on its degradation ratio, demonstrating high thermostability of 75% and 79% after boiling and sterilization, respectively. We suppose that the components playing a key role during this process were proteins, considering the decreased degradation rate caused by Proteinase K. Cell viability detection on HepG2 cells indicated that the degradation products were much less toxic than pure AFB₁. Furthermore, B204 cell-free culture supernatant also degraded AFB₁-contaminated food, such as peanuts, corn and cheese. These results suggested that this strain with AFB₁ degradation properties could be a prospective candidate for application in the food and feed industries.

Limosilactobacillus fermentum, Current Evidence on the Antioxidant Properties and Opportunities to be Exploited as a Probiotic Microorganism

The unbalance in the production and removal of oxygen-reactive species in the human organism leads to oxidative stress, a physiological condition commonly linked to the occurrence of cancer, neurodegenerative, inflammatory, and metabolic disorders. The implications of oxidative stress in the gut have been associated with gut microbiota impairments and gut dysbiosis. Some lactobacilli strains have shown an efficient antioxidant system capable of protecting against oxidative stress and related-chronic diseases. Recently, in vitro and experimental studies and some clinical trials have demonstrated the efficacy of the administration of various Limosilactobacillus fermentum strains to modulate beneficially the host antioxidant system resulting in the amelioration of a variety of systemic diseases phenotypes. This review presents and discusses the currently available studies on identifying L. fermentum strains with anti-oxidant properties, their sources, range of the administered doses, and duration of the intervention in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of L. fermentum strains with capabilities of inducing anti-oxidant effects and health-promoting benefits to the host, envisaging their broad applicability to disease control.

Associations between Serum Aflatoxin-B1 and Anemia in Pregnant Women: Evidence from Guangxi Zhuang Birth Cohort in China

Aflatoxin B1 (AFB1) is a common toxic mycotoxin and is detectable in pregnant women. Animal studies have revealed that AFB1 caused the lysis of erythrocytes and a decrease in hemoglobin. We conducted a prospective cohort study in Guangxi, China, in order to evaluate the association between AFB1 exposure and anemia in pregnant women during the entire pregnancy. A total of 616 pregnant women from the Guangxi Zhuang Birth Cohort were included in the study. Serum AFB1-albumin (AFB1-ALB) adduct levels were measured. The effect of AFB1-ALB adducts on hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were analyzed by using multivariable linear regression. The risks of anemia from AFB1-ALB adduct exposure were assessed by multivariable logistic regression. We found that the AFB1-ALB adduct was significantly associated with a decrease in Hb (β = -4.99, 95% CI: -8.42, -1.30), MCV (β = -4.58, 95% CI: -7.23, -1.94), MCH (β = -1.86, 95% CI: -2.87, -0.85), and MCHC (β = -5.23, 95% CI: -8.28, -2.17) in the first trimester with the third tertile of AFB1-ALB adducts when compared with the first tertile. Furthermore, the third tertile of the AFB1-ALB adduct significantly increased the risk of anemia by 2.90 times than compared to the first tertile in the first trimester (OR = 3.90, 95% CI: 1.67, 9.14). A significant positive does-response relationship existed between AFB1-ALB adduct levels and anemia risk (Ptrend = 0.001). When dividing anemia types, we only found that the third tertile of AFB1-ALB adduct increased the risk of microcytic hypochromic anemia (MHA) in the first trimester (OR = 14.37, 95% CI: 3.08, 67.02) and second trimester (OR = 4.75, 95% CI: 1.96, 11.51). These findings demonstrate the correlation between maternal AFB1 exposure during early pregnancy and risk of anemia, especially MHA, and during different trimesters in Southern China. More efforts should be made to diminish AFB1 exposure for pregnant women.

Dietary Curcumin Alleviated Acute Ileum Damage of Ducks (Anas platyrhynchos) Induced by AFB1 through Regulating Nrf2-ARE and NF-κB Signaling Pathways

Aflatoxin B1 (AFB1) is a stable toxic metabolite threatening health of human and animal and widely contaminated animal feed and human food. This present study aimed to investigate the effects of dietary curcumin on ileum injury in ducks induced by AFB1 administration and explore its underlying mechanisms. Ducks (N = 450, one-day-old male) with a similar weight were randomly assigned to 3 groups, containing the control group, AFB1 group (60 μg AFB1 kg⁻¹ body weight) and curcumin (500 mg curcumin kg⁻¹ diet) + AFB1 group. AFB1 administration markedly increased the ileum damage, AFB1-DNA adducts in the plasma and oxidation stress and inflammation. Adding curcumin into diet protected the ileum against morphology damage induced by AFB1 administration, decreased AFB1-DNA adducts in the plasma and eliminated oxidation stress and inflammation in the ileum of ducks. Anti-oxidation and anti-inflammatory effects of curcumin could protect the ileum against acute damage via activating Nrf2-ARE signaling pathway and inhibiting NF-κB signaling pathway. Conclusively, curcumin was a dietary anti-oxidation and anti-inflammation agent via activating Nrf2-ARE signaling pathway and inhibiting NF-κB signaling pathway to protect ileum against acute damage induced by AFB1 administration.

Bacillus amyloliquefaciens B10 can alleviate liver apoptosis and oxidative stress induced by aflatoxin B1

Aflatoxin B1 (AFB1) is a mycotoxin often found in food and livestock feed. It can affect human and animal health and is especially damaging to the liver. This study aims to evaluate whether Bacillus amyloliquefaciens (hereafter referred to as B. amyloliquefaciens) B10 can alleviate the toxic effects of AFB1 and, if so, what mechanism is responsible for its action. Specific pathogen-free (SPF) Kunming mice (5-6 weeks old) were divided into four groups (Control, AFB1, B10 strain, and AFB1 + B10 strain) and conducted continuously via gavage for 28 days. Oxidation indices (MDA, T-AOC, SOD, GSH-Px, and CAT) were then measured using their liver tissues and liver coefficient were calculated. Apoptosis was determined using the TUNEL method. Gene expression was determined for Bax, Bcl-2, BIP, CHOP, JNK, Caspase-12, Caspase-9, and Caspase-3, and protein expression was detected for Bax, Bcl-2, and Caspase-3. Our results showed that AFB1 induced the oxidative damage and apoptosis in the livers of mice. However, for mice given B. amyloliquefaciens B10, the biochemical indices, pathological changes, the expressions of genes and proteins related to oxidative stress and apoptosis were significantly reversed. The results indicate that B. amyloliquefaciens B10 antagonizes oxidative damage and apoptosis induced by AFB1 in the livers of mice. The results of this study are of significance for the future use of this strain to reduce the harm of AFB1 to human health and animal reproductive performance.

Aflatoxin Detoxification Using Microorganisms and Enzymes

Mycotoxin contamination causes significant economic loss to food and feed industries and seriously threatens human health. Aflatoxins (AFs) are one of the most harmful mycotoxins, which are produced by Aspergillus flavus, Aspergillus parasiticus, and other fungi that are commonly found in the production and preservation of grain and feed. AFs can cause harm to animal and human health due to their toxic (carcinogenic, teratogenic, and mutagenic) effects. How to remove AF has become a major problem: biological methods cause no contamination, have high specificity, and work at high temperature, affording environmental protection. In the present research, microorganisms with detoxification effects researched in recent years are reviewed, the detoxification mechanism of microbes on AFs, the safety of degrading enzymes and reaction products formed in the degradation process, and the application of microorganisms as detoxification strategies for AFs were investigated. One of the main aims of the work is to provide a reliable reference strategy for biological detoxification of AFs.

Aflatoxin B1 and Sterigmatocystin Binding Potential of Non-Lactobacillus LAB Strains

Research on the ability of lactic acid bacteria (LAB) to bind aflatoxin B1 (AFB1) has mostly been focusing on lactobacilli and bifidobacteria. In this study, the AFB1 binding capacities of 20 Enterococcus strains belonging to E. casseliflavus, E. faecalis, E. faecium, E. hirae, E. lactis, and E. mundtii, 24 Pediococcus strains belonging to species P. acidilactici, P. lolii, P. pentosaceus, and P. stilesii, one strain of Lactococcus formosensis and L.garviae, and 3 strains of Weissella soli were investigated in MRS broth at 37 °C at 0.2 µg/mL mycotoxin concentration. According to our results, among non-lactobacilli LAB, the genera with the best AFB1 binding abilities were genus Pediococcus, with a maximum binding percentage of 7.6% by P. acidilactici OR83, followed by genus Lactococcus. For AFB1 bio-detoxification purposes, beside lactobacilli, pediococci can also be chosen, but it is important to select a strain with better binding properties than the average value of its genus. Five Pediococcus strains have been selected to compare their sterigmatocystin (ST) binding abilities to AFB1 binding, and a 2-3-fold difference was obtained similar to previous findings for lactobacilli. The best strain was P. acidilactici OR83 with 18% ST binding capacity. This is the first report on ST binding capabilities of non-Lactobacillus LAB strains.