Prebiotics effect on growth performance, hepatic intermediary metabolism, gut microbiota and digestive enzymes of white sea bream (Diplodus sargus)

Abstract

This study aimed at evaluating the effects of short-chain fructooligosaccharides (scFOS), xylooligosaccharides (XOS) and galactooligosaccharides (GOS) on growth performance, hepatic metabolism, gut microbiota and digestive enzymes activities of white sea bream juveniles. Four diets were formulated: a control diet with fish meal (FM) and plant feedstuffs (PF) (30FM:70PF) and three test diets similar to control but supplemented with 10 g of scFOS, XOS or GOS per kilo diet, which were fed to fish during 12 weeks. Prebiotics had no effect on growth, feed efficiency or gut microbiota.Plasmatic triglycerides were lower in fish fed XOS than FOS and GOS diets. Malic enzyme activity was lower in fish fed XOS than FOS diet. Fish fed XOS diet had lower fatty acid synthetase (FAS), a key lipogenic enzyme and higher alanine aminotransferase activities. Fifteen days after the start of the trial, an enhancement of total alkaline protease, trypsin and lipase activities was observed in fish fed prebiotics, but such effect disappeared at 12 weeks. In conclusion, scFOS, XOS or GOS seem to have limited applicability in white sea bream feed. K E Y W O R D S

Prebiotics as functional ingredients: focus on Mediterranean fish aquaculture

“…Both in gilthead sea bream and white sea bream (Guerreiro et al . 2016c, ), it was observed a relation between gut microbiota population and digestive enzymes activities as the one reported in common carp by Hoseinifar et al . ().…”

“…2014a; Guerreiro et al . ,c,d, ), or even a tendency for decreased growth in fish fed high prebiotic levels (Hoseinifar et al . 2011b).…”

“…In white sea bream (53 g), scFOS, XOS or GOS incorporated at 1% in PF‐based diets induced no changes in gut microbiota after 12 weeks of feeding (Guerreiro et al . ) (Table ).…”

“…Studies that simultaneously measured digestive enzymes activities and gut microbiota population are, however, uncommon (Guerreiro et al . 2016c, ). Recently, Hoseinifar et al .…”

“…In white sea bream (53 g) fed 1% scFOS, XOS or GOS on a PF‐based diet, only minor effects were observed on digestive enzymes activities (Guerreiro et al . ) (Table ). At 15 days of trial, scFOS and XOS lead to an increase in total alkaline protease activity, whereas GOS increased trypsin activity.…”