Microbial manipulations to improve fish health and production – A Mediterranean perspective

Abstract

The interactions between the endogenous gut microbiota and the fish host are integral in mediating the development, maintenance and effective functionality of the intestinal mucosa and gut associated lymphoid tissues (GALTs). These microbial populations also provide a level of protection against pathogenic visitors to the gastrointestinal (GI) tract and aid host digestive function via the production of exogenous digestive enzymes and vitamins. Manipulation of these endogenous populations may provide an alternative method to antibiotics to control disease and promote health management. Applications of probiotics for Mediterranean teleosts can stimulate immune responses, enhance growth performance, feed utilisation, digestive enzyme activities, antioxidant enzyme activities, gene expression, disease resistance, larval survival, gut morphology, modulate GI microbiota and mediate stress responses. Although considerably less information is available regarding prebiotic applications for Mediterranean teleosts, prebiotics also offer benefits with regards to improving immune status and fish production. Despite the promising potential benefits demonstrated in current literature, obtaining consistent and reliable results is often difficult due to our incomplete understanding of indigenous fish GI microbiota and their subsequent host interactions which mediate and drive both localised and systemic host immunological responses. Additionally, the probiotic and prebiotic (biotics) mechanisms which mediate host benefits at the mucosal interface are poorly understood. Future studies focused on these interactions utilising gnotobiotic techniques should provide a better understanding of how to extract the full potential of biotic applications to promote immune function of Mediterranean teleosts.

Issues of Antibiotic Resistance in Aquaculture Industry and Its Way Forward

“…Probiotics are the live microbial feed additives that modulate gastrointestinal microbial communities of the host whereas Prebiotics are non-digestible forage additives stimulate the activity or abundance of beneficial gastrointestinal bacteria. Both of these have received widespread attention, showing the improved production, health and disease resistance of aquatic animals (Dimitroglou et al, 2011).When probiotics and prebiotics are used together to an animal so that the probiotic bacteria can grow easily with the help of the probiotics, this system known as the synbiotic.…”

Health Status of Marron, Cherax cainii (Austin, 2002) Fedcustomized Probiotic Bacillus mycoides

“…Supplementation of probiotics, particularly with host origin strains, restores and improves microbial population (diversity and density), as the added probiotic provides a favourable environment for the indigenous intestinal bacteria, whereas potential pathogens are suppressed [58,27,28,69,27]. Reduction of either population or diversity will reduce protection provided by the indigenous microbiota [29] and diminish other beneficial contributions including enzymes, amino acids, and vitamins [60][61][62]20].…”

“…However, other than immunity modulation, numerous health benefits could be obtained with probiotic supplementation [1] such as improved growth [8][9][10][11][12][13][14], improved enzyme activity [15][16][17][18][19][20] and improved stress tolerance [21][22][23], whereas modulation and restoration of intestinal bacteria population [24][25][26][27][28][29] as a contribution to the overall health status of the host has been underestimated [30,31].…”

Acceptance of fermented anchovy(Engraulis anchoita)

“…The anchovy processed by lactic acid fermentation is an alternative to the development of a new product (DiMitrogLou et al, 2011). The lactic acid fermentation is a method of food preservation and transformation by important chemical modifications of raw materials, forming preservative agents.…”