**Abstract**

The use of antibiotics as disease control agents has become contentious due to rise in drug-resistant bacteria such as *Psuedomonas aeruginosa* and *Aeromonas hydrophilla*. Studies have shown antibacterial potentials of some probiotics such as *Lactobacillus acidophillus* as promising alternative. Therefore, effects of diets fortified with *Lactobacillus acidophillus* on gut ecology and health status of African River prawn, *Macrobranchium vollenhovenii* were investigated. Prawns fed diets fortified with *Lactobacillus acidophillus* were challenged with *Psuedomonas aeruginosa* (1 × 107 cfu/mL) and *Aeromonas hydrophilla* (5 × 105 cfu/mL) using bath method for 14 days. Total viable and total enterobacteriaceae counts were determined on plate count agar and McConkey agar, respectively. Haemolymph (mL), total haemocyte count (cells/mL), catalase (mg/g protein), superoxide dismutase (mg/g protein, respiratory burst activity (μmoles) and survival rate (%) were evaluated using standard procedures. Data were analysed using descriptive statistics and ANOVA at p = 0.05. Results revealed that *Marobranchium vollenhovenii*-fed supplemented diets had reduced bacteria load, gut flora dominated by beneficial bacteria, enhanced immune system and protection against *Aeromonas hydrophila* at 103 cfu/mL inclusion level and could be used as immunodulation against *Aeromonas* infection.

**Keywords:** gut microbiota, innate immune response, infection, bacteria

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
