Primavera otoño 2020 (Año LXIII Núms. 122-123) Año LXIV Núm. 124-125 horizontes PRIMAVERA / OTOÑO 2021 PUCPR 56 such as the addition of hormones, vitamins, antibiotics, immunostimulants, antibiotics, and probiotics in hatcheries (Huerta-Rábago et al., 2019). Diseases in shrimp are directly related to gut microbiota since it dramatically influences shrimp physiology, metabolism, and host immunity (Angthong et al., 2020). The hepatopancreas is an organ in the digestive tract that contains a great variety of microorganisms; if an imbalance occurs in the shrimp flora, this causes the alteration of the organ, creating diseases (Guzmán-Villanueva et al., 2020). Another effect that hinders hatcheries is the production of toxins in the environment, such as poor water quality with high or meager contents of nitrogen compounds that could be controlled by maintaining a balance in the pond's microflora (Arias-Moscoso et al., 2018). The use of antibiotics in hatcheries There were three common bacterial genera in shrimp; Rhodopirellula, Vibrio, and Ketogulonigenium. Vibrio was one of the most important because some species were pathogenic for shrimp; therefore, the abundance of this genus in the natural shrimp flora could be harmful if the growth of Vibrio is not controlled (Huerta-Rábago et al., 2019). To control pathogens in hatcheries, aquaculturists use many chemicals and antibiotics. Usually, oxytetracycline, chlortetracycline, amoxicillin, and sulphadiazine are the common antibiotics added to shrimp hatcheries. However, this raises many concerns for the health of the human consumer (Dawood et al., 2019). Also, antibiotic treatment is ineffective, and some microorganisms have developed resistance to erythromycin, ampicillin, and nalidixic acid. Most microbial infections were susceptible to nitrofurantoin, chloramphenicol, oxytetracycline, and tetracycline (Babu et al., 2021). Thus, the development of natural and healthier alternatives is an urgent need for aquatic animal breeders (Dawood et al., 2019). Probiotics as alternative medicine in shrimp Researchers use probiotics to eliminate antibiotics in hatcheries (Huerta-Rábago et al., 2019). The objective is also to obtain sustainable farms that contain few toxins to avoid alternative problems and bring products that can be considered organic (Ferreira et al., 2017). Unlike mammals that acquire bacterial flora from their parents, shrimp obtain their intestinal flora from the environment. Many microorganisms compete with the shrimp immune system (Rajeev et al., 2021). The application of probiotics in shrimp hatchery food is to replace pathogenic bacteria with healthy bacteria in the gastrointestinal tract (Ahmmed et al., 2018). Several studies showed that Vibrio spp. pathogens become harmful to shrimp once the flora is altered. However, to reduce the risk of diseases, the application of probiotics should contain Bacillus spp. and Nitrobacter spp. for a healthy farm (Ferreira et al., 2017). Guzmán-Villanueva et al. (2020) demonstrated the difference in probiotic concentrations and their effect on the genetic expression of oxidative enzymes and bacterial composition in the digestive tract or hepatopancreas of shrimp. A higher concentration of probiotics was not necessarily beneficial because the ideal was to balance the concentration of the aqueous medium and the microorganism concentration (Guzmán- Villanueva et al., 2020). The concentration of the probiotic depends on the species to be cultivated; for shrimp, the ideal probiotic medium is concentrated with microorganisms to observe some physiological changes during the short term (Guzmán-Villanueva et al., 2020). Probiotics increase bacterial diversity within the pond and make droppings less toxic to shrimp species in hatcheries (Wang et al., 2020). The most common microorganisms used in the first antibiotics were lactic acid bacteria,