Biological reduction of aflatoxin M1 in dairy products using probiotic strains: a systematic review and meta-analysis

Aflatoxins are naturally occurring toxic substances produced mainly by species of the genus Aspergillus that can contaminate almost all foodstuffs. Apart from the harmful effects they have on human and animal health, they can be secreted unchanged in animal milk and cause contamination of milk and its products. Aflatoxin M1 (AFM1) is the major and most toxic type of aflatoxin after aflatoxin B1 (AFB1). The use of probiotic strains to reduce the amount of aflatoxin in milk and by-products has been observed in many studies. In this systematic review and meta-analysis, articles in PubMed, Scopus, Google Scholar and ISI Web of Science were searched to find eligible studies that reported reduction of AFM1 using probiotics in dairy products. The results were pooled using a random-effects model. In most studies, the efficiency of probiotics in milk has been tested by Lactobacillus strains. The results indicated that probiotic microorganisms could significantly reduce AFM1 by 55.76% (confidence interval (CI): 54.35%, 57.16%; I2 = 100%). Besides, the rank order of AFM1 reduction in dairy products based on probiotic strain subgroup was: Lactobacillus 51.99% (CI: 50.14%, 53.85%, I2 = 100%), Saccharomyces 67.36% (CI: 65.05%, 69.67%, I2 = 100%), Bifidobacterium 54.80% (CI: 54.18%, 55.43%, I2 = 99.9%), and 61.90% (CI: 53.80%, 70.00%, I2 = 100%) by a mix of strains. Considering the high binding potential of AFM1 to probiotic strains, these microorganisms can be recommended as a safe system to reduce AFM1 in dairy products.