Bentonite Clays as Adsorbent Material for Mycotoxins and the Hematological Parameters Involved in Tilapia Species: A Systematic Review

Abstract

Aquaculture allows sustainable fish farming to meet global demand; however, fish feed can contain mycotoxins and contaminate animals and humans. Bentonites are clayey materials composed mainly of montmorillonite and are used to reduce or diminish the toxicity of aflatoxins to animals and humans. In this sense, new cheap technologies from natural resources are necessary for controlling fungi and mycotoxins in food. However, information on the potential adverse effects on fish health and performance caused by adding bentonite clays to reduce mycotoxin exposure is scarce. Thus, this systematic review aims to analyze recent studies focusing on the use of bentonite clays as adsorbent materials for mycotoxins in fish feed. In this systematic evaluation of the literature on the subject, which was conducted in Cochrane, Science Direct, PubMed, and Scopus, 1,878 publications from the last 10 years were found, but 1,871 of them were excluded, leading to the selection of only seven for this study. The articles were classified according to the main theme of fish detoxification, the use of natural or chemically modified bentonite clays through adsorbents to remove mycotoxins. The results of the risk of bias analysis of the included studies (seven) were carried out according to the Down and Black criteria. The studies showed that hematological parameters such as total serum protein, albumin, alanine aminotransferase, aspartate aminotransferase, N-urea, and creatinine were altered in some fish species due to contamination by aflatoxin B1 in the diet. On the other hand, the use of bentonite reveals that it has the potential to reduce the effects of aflatoxicosis in fish, causing an increase in body weight, changes in serum enzymes related to humoral immunity, and changes in gill morphology and liver tissue. Contamination of fish diets (especially tilapia) by aflatoxins B1 produces severe changes in all investigated parameters and is extremely dangerous for fish productivity and public health. It was observed that adding clays to tilapia diets reduces the effects of aflatoxicosis while improving economic output and lowering health hazards by adsorbing aflatoxins B1. Thus, the use of bentonite clays is one of the most promising decontamination techniques that can be used by pisciculture.