Selective Manipulation of the Gut Microbiota Improves Immune Status in Vertebrates

Abstract

All animals develop in association with complex microbial communities. It is now well established that commensal microbiota is essential for the correct functionality of each organ in the host. Particularly, the commensal gastro-intestinal microbiota (CGIM) is a key factor for development, immunity and nutrient conversion, rendering them bio-available for various uses. Thus, nutritional inputs generate a positive loop in maintaining host health and are essential in shaping the composition of the CGIM communities. Probiotics, which are live exogenous microorganisms, selectively provided to the host, are a promising concept for manipulating the microbiota and thus for increasing the host health status. Nevertheless, most mechanisms induced by probiotics to fortify the immune system are still a matter of debate. Alternatively, prebiotics, which are non-digestible food ingredients, can favor the growth of specific target groups of CGIM. Several metabolites are produced by the CGIM, one of the most important are the short-chain fatty acids (SCFAs), which emerge from the fermentation of complex carbohydrates. SCFAs have been recognized as key players in triggering beneficial effects elicited by simple diffusion and by specific receptors present, thus, far only in epithelial cells of higher vertebrates at different gastro-intestinal locations. However, both strategies have shown to provide resistance against pathogens during periods of high stress. In fish, knowledge about the action of pro- and prebiotics and SCFAs is still limited. Thus, in this review, we briefly summarize the mechanisms described on this topic for higher vertebrates and discuss why many of them may operate in the fish gut representing a model for different mucosal tissues

Fish intestinal microbiome: diversity and symbiosis unravelled by metagenomics

“…Nevertheless, we are still in the early stages of understanding the complex interactions between the gut microbiome and its host and how the bacterial communities can be most effectively manipulated to improve fish health and aquaculture production (Montalban‐Arques et al . ).…”

Dietary effects of soybean products on gut microbiota and immunity of aquatic animals: A review

“…Even though some papers addressed the effect of SBM, SPC and SO on the gut microbiota of fish, further investigations are needed, as the intestinal microbiota influence: development, digestion, nutrition, immunological functions and disease resistance (Montalban‐Arques et al., ; Romero, Ringø, & Merrifield, ). According to Purchiaroni et al.…”

B cells and their role in the teleost gut

“…However, while colonization with normal microbiota has a positive effect on host immune regulatory functions, any disturbance by stress, antibiotic treatment and other factors may contribute to the development of disease (Pérez et al, 2010). Not surprisingly, the manipulation of microbiota has recently received more attention and these new findings have been summarized in a number of extensive reviews (Lazado et al, 2014; Montalban-Arques et al, 2015; Nayak, 2010). Despite recent progress, the influence of microbiota composition on mucosal B lymphocytes of teleost remains largely unknown.…”