Yeast β-Glucans as Fish Immunomodulators: A Review

Abstract

Administration of immunostimulants in fish is a preventive method to combat infections. A wide variety of these biological molecules exist, among which one of the yeast wall compounds stands out for its different biological activities. The β-glucan that forms the structural part of yeast is capable of generating immune activity in fish by cell receptor recognition. The most frequently used β-glucans for the study of mechanisms of action are those of commercial origin, with doses recommended by the manufacturer. Nevertheless, their immune activity is inefficient in some fish species, and increasing the dose may show adverse effects, including immunosuppression. Conversely, experimental β-glucans from other yeast species show different activities, such as antibacterial, antioxidant, healing, and stress tolerance properties. Therefore, this review analyses the most recent scientific reports on the use of yeast β-glucans in freshwater and marine fish.

Stakeholder perspectives on the 2023 Ghana National Aquaculture Development Plan: An integration within the ecosystem approach framework

“…This can reduce the development of drug‐resistant bacteria and increase the effectiveness of antibiotic treatments. Alternative treatments through immunostimulants, namely β‐glucans plant‐based products such as neem tree leaves and ginger, to enhance the immune system are considered sustainable options (Collado‐González & Esteban, 2022; Machuca et al., 2022; Mohammadi et al., 2020; Zornu et al., 2023). Disease management was among the justifications as farmers treated infected fish in desperation (Table 3).…”

O uso de imunomoduladores na alimentação de peixes: Uma revisão

“…O mecanismo de ação do β-glucano se dá por meio de receptores específicos na superfície dos macrófagos. Nos peixes, o β-glucano pode favorecer a estimulação dos mecanismos de defesa não-específicos, estimulando a atividade fagocitária dos macrófagos e aumentando assim sua capacidade para eliminar os patógenos (Machuca et al, 2022).…”

Hematological changes in Florida pompano (Trachinotus carolinus) supplemented with β‐glucan and Pediococcus acidilactici synbiotic

“…Their immunomodulatory properties are suspected to be related to their molecular structure (degree of branching) and molecular weight with high‐molecular‐weight β‐glucans, with branching ratios between 0.2 and 0.33, generally being the most potent immunomodulators (Hadiuzzaman et al, 2022; Han et al, 2020; Rieder et al, 2011). Because β‐glucans are components of yeast and fungal cell walls (composing 30%–60% of Saccharomyces cerevisiae cell walls), they are recognized by pattern recognition receptors (PRRs), like the C‐type lectin receptor dectin‐1 (also known as β‐glucan receptor) (βGR), scavenger receptor (SR), complement receptor 3 (CR3), and toll‐like receptor (TLR) as pathogen‐associated molecular patterns (PAMPs) and thus trigger both pro‐inflammatory (IL‐1β, IL‐9, IL‐6, and TNF‐α) and anti‐inflammatory (IL‐10 and IL‐11) cytokine release and immunological gene expression (del Valle et al, 2023; Machuca et al, 2022; Meena et al, 2013; Petit et al, 2019; Pogue et al, 2021). Beta‐glucans have proven to be an effective immunostimulant in fish with several papers reviewing the modes of action and beneficial effects in detail (Hadiuzzaman et al, 2022; Machuca et al, 2022; Meena et al, 2013; Petit & Wiegertjes, 2016; Pogue et al, 2021; Rojo‐Cebreros et al, 2018).…”

“…Because β‐glucans are components of yeast and fungal cell walls (composing 30%–60% of Saccharomyces cerevisiae cell walls), they are recognized by pattern recognition receptors (PRRs), like the C‐type lectin receptor dectin‐1 (also known as β‐glucan receptor) (βGR), scavenger receptor (SR), complement receptor 3 (CR3), and toll‐like receptor (TLR) as pathogen‐associated molecular patterns (PAMPs) and thus trigger both pro‐inflammatory (IL‐1β, IL‐9, IL‐6, and TNF‐α) and anti‐inflammatory (IL‐10 and IL‐11) cytokine release and immunological gene expression (del Valle et al, 2023; Machuca et al, 2022; Meena et al, 2013; Petit et al, 2019; Pogue et al, 2021). Beta‐glucans have proven to be an effective immunostimulant in fish with several papers reviewing the modes of action and beneficial effects in detail (Hadiuzzaman et al, 2022; Machuca et al, 2022; Meena et al, 2013; Petit & Wiegertjes, 2016; Pogue et al, 2021; Rojo‐Cebreros et al, 2018). The antioxidant effects of β‐glucans and other prebiotics likely center around their immunostimulant activity through the activation of immune cells, production of mitochondrial reactive oxygen species, and their role in subsequent expression of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione‐s‐transferase (GST), and glutathione peroxidase (GSH‐Px) (Machuca et al, 2022; Pogue et al, 2021).…”

“…Beta‐glucans have proven to be an effective immunostimulant in fish with several papers reviewing the modes of action and beneficial effects in detail (Hadiuzzaman et al, 2022; Machuca et al, 2022; Meena et al, 2013; Petit & Wiegertjes, 2016; Pogue et al, 2021; Rojo‐Cebreros et al, 2018). The antioxidant effects of β‐glucans and other prebiotics likely center around their immunostimulant activity through the activation of immune cells, production of mitochondrial reactive oxygen species, and their role in subsequent expression of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione‐s‐transferase (GST), and glutathione peroxidase (GSH‐Px) (Machuca et al, 2022; Pogue et al, 2021). Probiotics are live microorganisms that, when supplemented at adequate amounts and duration, confer increased viability, enhanced immune function, and promote the growth and general welfare of a host (Ringø et al, 2010).…”