Locally adapted gut microbiomes mediate host stress tolerance

Abstract

While evidence for the role of the microbiome in shaping host stress tolerance is becoming well-established, to what extent this depends on the interaction between the host and its local microbiome is less clear. Therefore, we investigated whether locally adapted gut microbiomes affect host stress tolerance. In the water flea Daphnia magna, we studied if the host performs better when receiving a microbiome from their source region than from another region when facing a stressful condition, more in particular exposure to the toxic cyanobacteria Microcystis aeruginosa. Therefore, a reciprocal transplant experiment was performed in which recipient, germ-free D. magna, isolated from different ponds, received a donor microbiome from sympatric or allopatric D. magna that were pre-exposed to toxic cyanobacteria or not. We tested for effects on host life history traits and gut microbiome composition. Our data indicate that Daphnia interact with particular microbial strains mediating local adaptation in host stress tolerance. Most recipient D. magna individuals performed better when inoculated with sympatric than with allopatric microbiomes. This effect was most pronounced when the donors were pre-exposed to the toxic cyanobacteria, but this effect was also pond and genotype dependent. We discuss how this host fitness benefit is associated with microbiome diversity patterns.

Microbiome mediated tolerance to biotic stressors: a case study of the interaction between a toxic cyanobacterium and an oomycete-like infection in Daphnia magna

“…Analysis of the recipient microbiomes showed that selection of bacterial groups was also stressor dependent, with a stronger selection of bacterial strains in the Microcystis and combi treatment in Daphnia that received a natural microbial inoculum, as shown in the beta diversity analysis. This is conform as suggested in Macke et al (2017Macke et al ( , 2020 and Houwenhuyse et al (2021).…”

“…Body size, in addition, was lower for individuals exposed to Aspergillus compared with the control, whereas the opposite was observed for the total number of brood. Trade-offs between survival and body size under stress were previously found in Daphnia (Adamczuk 2010 and other organisms (Sterck et al 2006, Mogensen andPost 2012) with Houwenhuyse et al (2021) suggesting a role of the microbiome for this trade-off under Microcystis stress. Here, we did, however, not find support for such a trade-off.…”

“…The first brood of the second generation was discarded, whereas eggs from the second brood were collected to obtain axenic (i.e. germ-free) juveniles following protocol from Bulteel et al (2021) and Houwenhuyse et al (2021).…”

Gastrointestinal Development and Microbiota Responses of Geese to Honeycomb Flavonoids Supplementation

“…The gut microbiome is considered the host second genome, which emerged as a key determinant of many aspects including the capability of shaping developmental, physiological and reproductive phenotypes ( 5 ), the enhancement of feed digestibility and nutrient absorption throughout the digestive tract ( 2 ), and the inhibition on intestinal pathogenic bacteria ( 6 ). Further, unlike other environmental factors, the microbiomes may be transmitted between generations carrying the potentiality to alter traits beyond the limits of the host's genetics ( 7 ), and further worked on shaping the phenotypes of the progenies.…”

“…Further, unlike other environmental factors, the microbiomes may be transmitted between generations carrying the potentiality to alter traits beyond the limits of the host's genetics ( 7 ), and further worked on shaping the phenotypes of the progenies. Previous studies showed that gut microbiome is highly malleable by environmental factors ( 5 ) while symbiotic bacteria can increase bioavailable nutrient pools ( 7 ), which ultimately benefited the growth of the eukaryotic host.…”