The US catfish aquaculture industry faces numerous reoccurring challenges, including fish losses from environmental stressors and infectious diseases. The consequence of prolonged stress within an aquaculture setting is a general decrease in production efficiency, especially decreased growth and disease resistance. Over time, stress modulation and disease treatment have been limited to the use of chemical drugs. How ever, there has been a growing focus on safer alternatives because these chemical drugs are known to have various adverse effects on the environment and human health. In this experiment, therefore, we wanted to investigate if t ryptophan as a nutraceutical could modulate farming stress and increase immune responses against virulent Aeromonas hydrophila (vAh; ML09-119) . We had four different experimental groups of channel catfish (Ictalurus punctatus): (1) control fish fed with control feed, (2) control fish fed with tryptophan-treated feed; (3) stressed fish fed with control feed; and (4) stressed fish fed with tryptophan- treated feed. After five weeks of feeding, we challenged the catfish with vAh and kept the fish in the challenged condition for 72 hours. We collected fish blood samples and extracted serum for sera lysozyme activity analysis before and after the disease challenge. Based on our preliminary data, tryptop han increased the lysozyme activity in both stressed and unstressed groups before and after the disease challenge. An increased lysozyme activity could infer an overall improvement in the innate immune response of fish under different rearing conditions. If proven, this finding may change the farming practices of catfish and reduce the usage of chemical treatments while maximizing profits and protecting the environment.