Nutritional Programming Improves Dietary Plant Protein Utilization in Zebrafish Danio rerio

Abstract

33Nutritional Programming (NP) has been shown to counteract the negative effects of dietary plant 34 protein (PP) by introducing PP at an early age towards enhancement of PP utilization during later 35 life stages. This study explored the effect of NP and its induction time on growth, expression of 36 appetite-stimulating hormones, and any morphological changes in the gut possibly responsible 37 for improved dietary PP utilization. At 3 days post-hatch (dph) zebrafish were distributed into 12 38 (3 L) tanks, 100 larvae per tank. This study included four groups: 1) The control (NP-FM) group 39 received fishmeal (FM)-based diet from 13-36 dph and was challenged with PP-based diet 40 during 36-66 dph; 2) The NP-PP group received NP with dietary PP in larval stage via live food 41 enrichment during 3-13 dph followed by FM diet during 13-36 dph and PP diet during 36-66 42 dph; 3) The T-NP group received NP between 13-23 dph through PP diet followed by FM diet 43 during 23-36 dph and PP diet during 36-66 dph; and 4) The PP group received PP diet from 13-44 66 dph. During the PP challenge the T-NP group achieved the highest weight gain compared to 45 control and PP. Ghrelin expression in the brain was higher in T-NP compared to NP-FM and 46 NP-PP, while in the gut it was reduced in both NP-PP and T-NP groups. Cholecystokinin 47 expression showed an opposite trend to ghrelin. The brain neuropeptide Y expression was lower 48 in NP-PP compared to PP but not different with NP-FM and T-NP groups. The highest villus 49 length to width ratio in the middle intestine was found in T-NP compared to all other groups. The 50 study suggests that NP induced during juveniles stages improves zebrafish growth and affects 51 digestive hormone regulation and morphology of the intestinal lining -possible mechanisms 52 behind the improved PP utilization in pre-adult zebrafish stages. 53 54 56Replacement of fishmeal (FM) in fish diets with plant protein (PP) has been an ongoing 57 challenge in the aquaculture industry. High-quality PP sources such as soy or pea protein 58 concentrates and wheat or corn gluten have been widely used by the feed industry since their 59 digestibility in some species is comparable to FM. However, their price can often exceed the cost 60 of marine raw materials. Although some progress with utilization of lower-quality PP, such as 61 soybean meal, has been made, a number of concerns must still be overcome including low 62 palatability, imbalanced amino acid profile, and a presence of anti-nutritional factors responsible 63 for inducing intestinal inflammation, to maintain acceptable growth rates and feed efficiency 64 values at high FM substitution levels. Thus, the aquafeed industry has focused on ways to 65 include some of the more cost-effective alternative sources of protein that will not only help to 66 further replace FM but also substitute some of the expensive high-quality PP concentrates and 67 provide more flexibility in feed formulations using a wider range of available raw materials. 68Nutritional progra...

The Effect of First Feeding Exposure of Larval Largemouth Bass to a Formulated Soybean Meal‐Based or Soy Saponin‐Supplemented Diet on Fish Growth Performance and Gut Microbiome

“…Similarly, Zambonino‐Infante et al (2019) reported that European Bass Dicentrarchus labrax that were programmed with a high‐carbohydrate diet (34%) at mouth opening (6 dph) did not achieve higher weight gain compared to the non‐programmed fish. Conversely, Kwasek et al (2020) exposed Zebrafish to an SBM diet at 13 dph (stage of postmetamorphosis), and the programmed fish achieved a higher weight gain than non‐programmed individuals when an SBM diet was provided again to adults. This suggests that the NP method and fish age are critical for observing positive NP effects.…”

“…Nevertheless, it appears that ingestion of the SBM diet alone does not suffice for NP to take effect. Perhaps if the NP stimulus was introduced at a later stage (in the form of a dry diet) when fish were fully metamorphosed (Kwasek et al 2020) or introduced in a different form (e.g., SBM‐enriched Artemia nauplii), an induced epigenetic change would have been reflected by the different phenotype of the NP‐PP group during the PP challenge.…”

“…Nutritional programming has only recently received more consideration in fish, and some studies already report the possibility of "imprinting" fish at a young age with alternative ingredients or nutrient levels to improve their utilization later in life. Although there has been a successful attempt to program the next generation of fish through broodstock feeding (Izquierdo et al 2015), most of the fish NP studies have focused on introducing the nutritional trigger during larval (Vagner et al 2007;Perera and Yúfera 2016;Zambonino-Infante et al 2019;Kwasek et al 2020;Molinari et al 2020) and juvenile (Geurden et al 2013(Geurden et al , 2014Kemski et al 2018) stages. These studies have presented various outcomes, many of which were likely affected by the acceptance of diets designed for NP.…”

“…Geurden et al (2013), who first reported successful NP with PP in Rainbow Trout, suggested 21 d. The general notion, however, would imply that NP should be long enough to expose the animal to the potential NP trigger and short enough to prevent any negative side effects caused by prolonged exposure. The mechanism behind NP is also not fully understood, although the few investigations available on NP with PP indicate possible endocrine and morphological adaptation of the digestive system (Kwasek et al 2020;Molinari et al 2020) and/or modulation of pathways regulating the sensory perception of odor, taste, and vision (Balasubramanian et al 2016). Nutritional programming has been found to be a promising approach to offset some of the negative effects of PP (Kwasek et al 2020;Molinari et al 2020).…”

“…The mechanism behind NP is also not fully understood, although the few investigations available on NP with PP indicate possible endocrine and morphological adaptation of the digestive system (Kwasek et al 2020;Molinari et al 2020) and/or modulation of pathways regulating the sensory perception of odor, taste, and vision (Balasubramanian et al 2016). Nutritional programming has been found to be a promising approach to offset some of the negative effects of PP (Kwasek et al 2020;Molinari et al 2020). Clarkson et al (2017) programmed Atlantic Salmon with a 90% wheat gluten-based diet, and when fish were challenged with a wheat gluten diet later in life, the previously programmed fish achieved a 24% higher average weight compared to nonprogrammed individuals.…”