Portal de Periódicos da CAPES

Probiotic Modulation of the Gut Microbiota of Fish

2014; Wiley; Linguagem: Inglês

10.1002/9781118897263.ch8

1365-2095

Daniel L. Merrifield, Oliana Carnevali,

Aquatic life and conservation

A growing body of literature is available on the effects of probiotics on fish growth performance, digestive function, immunity, disease resistance, fecundity, oxidative stress and deformities but, perhaps surprisingly, many of these studies have not investigated the effect of probiotic applications on the gastrointestinal (GI) microbiota. Despite the debate on the precise definition of a ‘probiotic’ for aquaculture applications, the different definitions are consistent in that host benefits are driven, in part at least, by modulation of the host microbiota. Too often fish probiotic studies either lack a microbial investigation, or conduct the minimum assessment: enumeration of probiotic levels. Given the complexity of the gut microbiome, and its importance to the host, it is not sufficient to determine only the probiont levels and to attribute host benefits solely to the direct presence of the probiotic, which is usually only present as a minor component of the total microbial population. Changes in the indigenous populations must be examined as these potential changes are also factors involved in driving host benefits. This chapter summarizes the findings of studies which have addressed this topic and discusses the data to support the claims of probiotic ‘colonization’. From the literature it is clear that a greater emphasis on understanding the effects of probiotics on the complex microecology of the GI tract of fish is essential, and future studies must incorporate quantitative techniques to determine microbial abundance as well as elucidating microbial functionality and activity.